Sbc 64cc heads compression ratio chart. Staying at 64cc with a .
Sbc 64cc heads compression ratio chart My first though it to check valve adjustment. arms,Ground up disc brake Jan 14, 2022 · Question: W/ 302 Chevy 4" bore 3" stroke (Z-28 motor) . 64cc Cylinder Heads, Should give me the desired compression ratio. Choose a flat top piston and play with the Piston Down Bore number to get 9. metal gasket of . Jun 21, 2014 · Running the 70cc heads with same . Feb 16, 2011 · I need to find out the compression ratio of my 96-00 stock 350 5. Sep 26, 2018 · I think it is doable or even take a little more out of the Heads? Static compression ratio of 10. Apr 30, 2020 · 1957 283 power pak heads. Apr 23, 2020 · The 383 has domed pistons 11. The amount the piston is under the deck makes a pretty big difference in compression ratio. Nov 1, 2000 · Number Crunching. I don't have all the specs of the motor to figure the compression ratio, but I know it is 8. Dec 8, 2004 · A 406 with flat tops and 58cc chambers makes 12. Use (-) for Dome and (+) for Dish. Your crate motor may have dished pistons which would end up giving you a low compression ratio with the 72cc heads. 020 steel shim head gasket. Depending on the amount of material removed, the intake may also require milling to compensate. what i'm reading is that a 400 with the stock 24cc dish volume pistons with the 64cc heads would have a compression ratio of 9. Apr 12, 2019 · For example, the Dart 215cc aluminum head is offered in both 64cc and 72cc chamber sizes. Aftermarket heads 64cc=lower compression. My first car back in Dec '71. From doing research it appears it makes around 10. 25:1 compression ratio 63. Castings ending in 191 are the low compression 76cc head. 3 to 1 you will need the above specifications on your motor. Jun 5, 2012 · I'm trying to get an accurate compression estimate because i just bought a set of 305 cylinder heads 601 casting which have been ported and machined to have 58cc chambers and 2. 25 CR points. If you're interested in building a 383, search the Chevy forum for "stroker" and you'll hit some good info. The compression ratio is the ratio between two elements: the gas volume in the cylinder with the piston at its highest point (top dead center of the stroke, TDC), and the gas volume with the piston at its lowest point (bottom dead center of the stroke, BDC) Jul 26, 2015 · Vortec heads will accept more compression than old open chamber heads without detonation, the distributor needs to be curved to not more than 34 to 36 degrees total. specific Compression Ratio you are looking for. com when used with 64cc heads (mortec. Is anyone running a similar combo and with what compression ratio? With this roller cam and heads on a 350 Iam running 9. 041 inch thick head gasket and the piston is between 0. Just by changing to smaller 64cc heads, the compression ratio improves from 8. 5:1 or slightly less, there are many factors as well as this is a ball park figure without exact measurements and a compression calculator. Apr 17, 2010 · Craig 70' ElCamino 414 BBC,781 heads stock valves bowl blend and port smooth,1. Then change the head to 64cc and the gasket to . 1 Feb 12, 2008 · I also have a question for you. 7:1 static compression I believe (18cc dished pistons with the Etec 170 heads 64cc chambers) and it runs great on pump gas. 5:1 is the max CR recommended for iron heads on an SBC. Remember you can use different thickness head gaskets to alter the CR. 039 gasket will put it at 9. 038 compressed gasket thickness piston . 7% by going from 8:1 to 10:1 but only 2. 02 intake and 1. Let's take a look at how all these volumes interact by detailing the simple math that's used to determine compression ratio. 7 vortec engine w/std bore. Rialto Ave. and so on. 25:1. 3:1 if the head is 64cc. 2 bolt blocks are used in light duty high compression trucks. 040" over Vortec heads cut guides and springs good to . 8. 23 Mount Erin Rd, Blair Athol NSW 2560, Australia +61 2 9607 2299 Check this, there are some variables to take into account when calculating the compression ratio, this site will hopefully make it easier for you. 2:1 with the 75cc heads and 10. I have three different heads to choose from. Speed Pro says that with connecting rods, heads and overbore I should be producing a 9. These guys also say that for running pump gas, cranking pressure should not exceed 165, although I have witnessed fellows using 200+ with everything matched up well and the chamber and piston cleaned up to prevent hot Mar 8, 2005 · That compression will be good with a 294 cam. That would be perfect. Nov 27, 2022 · The heads are 64cc. 1 will burn regular maybe even at 9. rule thump for compr. Except for 2 or 4 bolt blocks the bottom ends are the same. Oct 24, 2019 · Current thinking puts the static compression ratio limit at 9. They are TRW L 2304 030 oversize. Jan 18, 2012 · I have the dreaded 350ci 290hp sbc crate motor from GMPP. However, as it's already been mentioned, you'll need to know what the piston to deck clearance is. I'm looking for a streetable "pump gas" engine with compression around 9. 1/10 of a point for every . 0:1 compression ratio 76. Assuming the above, a 72cc chamber would put you at around 9. Maybe this will help. 319 dome,MSD,Holley 850 vac sec. They had flat top pistons and 64CC heads. A change to the 64cc heads will bring the actual ratio up to about 9:1, depending on all the other factors outlined in the equation above. With the 64cc heads you can always use thicker headgaskets or have the chambers cleaned up and polished to drop the C/R. 8+ to 1 compression with a 64cc head, and that is if the block was not deckedif block was decked, it will be over 11 to 1, as high as 11. Nothing else will Aug 22, 2010 · It has iron 462 Camel Back heads @ 64cc making for a 9. What is finaly my compression ratio? Is it 10. a set of 64CC heads or even 70CC heads will wake up a SBC with power due to improved flow and combustion chamber size. 2:1 while the larger 72cc chamber reduces the compression to 9. 2:1 w/ typical flattop. Sep 3, 2022 · So this is kind of a revisited thread from a post I created a little while ago about 400 compression. Sep 24, 2004 · I'd go with the 64cc heads which would allow flexibility in you choosing the compression ratio. 79:1. 040" thick, a down in the hole piston of about a stock . I've seen several cases where guys swapped 64cc heads onto a dished piston 400, all had nasty problems with pinging/detonation. 01:1 (too much for iron heads and pump gas). 3. I'm thinking the compression ratio might be too high with 64cc's but maybe the vortec's efficient combustion chamber might allow it to work? Dec 30, 2009 · Sample: 4. 024 inch below the deck. iron heads, stock or stock type cam, higher compression = detonation on pump gas. 7 pump gas)? Or it would be better to go for 70cc heads? With everything the same but the 70cc heads the results are SCR 10:1, and DCR 7. you should forget those 58cc cast iron heads. I've got Vortecs at 64cc, Bowtie phase II at 64cc and also have some 441's and 882's at 76cc. Even if you have flat top pistons with valve reliefs, you need to add cc's. 12 :1. 3:1. Jul 24, 2000 · Using Pat Kelly's calculator your dynamic compression ratio is a little over 7. 50 less compression also. 5:1 with 76cc heads. My 406 is running a 285* cam on 106*LDA with 10. Aug 17, 2006 · You could get 10. Nov 11, 2001 · the size of the combustion chamber ultimately changes the compresion ratio the 76 cc will lower the comp. 704" lift, Billet Hogan's Intake with W2A Intercooler, Holley Dominator EFI on E85, Injector Dynamics ID2000 Injectors, Stef's #1705R oil pan May 20, 2019 · I plugged my numbers into a compression ratio calculator and got that number. I have a 400 sbc with 125 compression per cylinder. I looked up flat top 327 pistons in summits catalog and they claim to give a 327 with 64 cc heads a 9. It shows for example a gain of 3. id rather stay around 10. 5:1 with a 64cc chamber, the heads below could be the hot ticket. 0. Roller,Speed pro +. 48" crank (/2) = 1. 25-. 789:1 Dynamic: 8. (in fact the link you posted shows 9. Mar 22, 2011 · Use Summit's compression ratio calculator. 32:1 . Using the OP's specs shown above You could bore block to 4. I think . 010” removed the on heads or block. but I'm using stock pistons and need to make sure my compression will be fine. 02/1. When your heads are off you can measure your deck height and figure your piston relief and go somewhere like smokemup. If you want to figure it more closely, you must know exactly which piston & gasket will be used. the compression is 8. Jump to Latest 2. 5:1 to 9. 6 to 1 on 64cc ). 7" rod = 7. 5 with 64cc. Then you can calculate your static compression ratio. 041" is the thickest you can buy, and I'm running . 005" cut I don't like putting them together with wide quench either, they can get finicky on fuel grade with wide quench. If you are building an engine on a budget, think about the economics of heads and pistons. 015" to above . I also looked up the cam specs and ran what your dynamic compression will be, with the 76cc heads it is 7. 9. The 1969-70 350/300 with it's 10. Apr 8, 2011 · Most folks are doing the opposite, exchanging 76cc heads for 64cc heads to raise their compression ratio. Dec 8, 2002 · 400 SBC COMPRESSION RATIO. 82 overdrive gear,Quick Performance 9",True trac posi 3. 04 bore 3. m. For example, if your block was zero decked, the compression would be 9. I want to build a 350 Chevy with iron heads and a 10. I used this compression ratio calculator. Here's the plan so far: 383 Stroker; 9:1 compression: This sucker's going to run on 87 octane and like it. Feb 21, 2009 · These are replacement 1970 LT1 pistons and TRW says thay produce 10. 015, gasket bore 4. Use headgaskets anywhere from . 030 deck height, 5cc valve reliefs, and a . Your dynamic compression ratio is 8. Oct 6, 2008 · The heads are aluminum but what is the limit with pump gas. 015 gasket, that puts it at 9. 12. That should be compatible with premium gas. Oct 25, 2022 · KB piston site has a great calculator for compression ratio if you know the piston cc’s, thickness/diameter of gaskets, piston to deck, bore , stroke, etc. I would put them into '79 350 cid sb Chevy with stock 76 cc iron heads, Crane 296 Fireball cam and st Feb 22, 2011 · If the heads are still 64cc and haven't been ground bigger in the chamber to deshroud the valves, using a flat top piston in a undecked block you will only get about 9. 038 for the Felpro head gasketThis seems low to meI would expect around a point higherIs this a bad calculator or are my inputs off? Nov 18, 2010 · swapping from that dished piston to a flat top will increase compression but nothing really to write home about. 07:1 compression ratio. 005; Install 64cc (or 65cc) heads; Install the H345DCP30 pistons (1. I am going to do a build similar to the Goodwrench quest in Chevy Feb 19, 2005 · Go over to the ROSS Racing Pistons website and play with their "Compression Ratio Calculator" sim. 8:1 with no problems even on 87 octane. As a guess …. 030 Pistons Dome column: 0 Cylinder head volume: 60 cc 10. With 22cc dish pistons and 64cc heads the compression ratio will be 9. Info from Chevrolet specifications and backed up by Alan Colvin's Chevrolet by the Numbers 1965-69 and 1970-75 editions. 5:1 for use with iron heads and 10. 35 would be good with the XE268 cam and a 72cc iron head IMO. 1 with 57cc heads it goes up to 9. 000 bore - 3. 025, stroke 3. Less on smaller engines. Apr 10, 2023 · I have a 355ci small block Chevy that I bought that has dished pistons but I don’t know anything about them. Your dynamic cranking pressure is 166. 030 Sep 17, 2006 · I bought a set of speed pro hyper H615P +. 76 PSI. If we apply both chamber sizes to a flat-top 350ci small-block with 6cc valve reliefs, the compression ratio for the 64cc head would be 10. Effective stroke is 2. 2:1. Dec 29, 2003 · Just by switching to 64cc heads your compression goes to 11. Remember also that OE heads that are called 64cc rarely are that small unless you mill them. 5 to 1. 445/. 8:1 compression Hoping it will run well. 041" head Mar 22, 2008 · I had to rebuild the original 283 in my 64 Chevelle. 0:1 compression ratio. these are not dragster heads, but with a mild porting the will flow very well. I'm going to keep using the MSD programmable ignition which may give me some options. Feb 9, 2011 · 385 sbc 4. What options for pistons are there for the 327 with 64cc heads to keep compression ration around 9- 9. 039" on mine. 5 with these heads the trucks they originally came on were scheduled for regular 87 unleaded. 3just ran across it by accident. 060 Dart SHP 180cc runner/64cc chamber Summit 1103 cam. It has 76cc heads and an advertised compression ratio of 8. Dec 22, 2014 · You really need to do the compression ratio calculations or use an online calculatorbecause a flat top piston 400 is 10. You can buy a pair of new Vortecs for only a little more than a premium rebuild of the 76cc heads. [ 03-14-2004, 01:48 PM: Message edited by: Eric68 ] Compression Calculator. 2:1 as Federal Mogul declares? Sep 26, 2016 · Here are the figures I used to figure cr. So I was wondering what compression ratio that would make? Oct 25, 2014 · My . 030"-over, old TRW pistons rated at 11. 5:1 compression. 781 (350 Chevrolet) with a compression ratio of 8. May 12, 2008 · 95% of piston manufacturers calculate their compression ratios with these specs. 76 cc chamber, a flat top piston, . Sep 8, 2007 · Or Vette aluminum heads like your ZZ4 has on it. 039 gasket i'd get 10. 025". I am thinking this is a little low, compression ratio calculator numbers are as follows: Static: 9. Jun 6, 2020 · Working on a fresh rebuilt 350, and I did a compression test, all cylinders read 140 psi. 64cc heads and flat-top pistons are about perfect for a little 307. 00, Head gasket compressed thickness . Are you stuck with EITHER the 58cc heads or the flat top pistons? There are a few things you can do with pistons and/or heads to get your CR back down into pump gas territory. Nov 13, 2013 · With a 64cc head this engine will only be 9:1 comp. Mill the heads to 64cc would get 10. I went back with flat top pistons and the original heads. 4 bolt blocks are more complicated they can be found in some light duty and 1101 W. 6:1. Aug 4, 2006 · Just use the compression ratio calculator by clicking on the link below. With the 280 cam the DCR was too high. Aug 9, 2003 · i have a set of 882's on my 350 with the 4 dish pistons. e. How much will this add to my compression ratio? May 25, 2005 · I've been doing a lot of reading in the bowtie forum. 02 and use a g. He's running a sloid mechanical255/266 duration & 540/534 lift Comp cam, 461 heads 2. 030 over with 64cc headsI figured in . 040 over to get a clean cylinder wall. I really dont want to burn my pistons up. Feb 12, 2008 · If it is the case that your pistons will put you at 10. I have been thinking about putting some new edelbrock e tec cylinder heads on it with 64cc chambers. 5 exhaust pipe it cam guessing 9-1 compression its in 3400 pd jeep 411 4 speed engine seems a little under powered what do you recommend different cam thiner head gadgets thanks for any input Apr 4, 2002 · A friend of mine has a set of TRW forged pistons and I'd like to buy them. com says 64cc) in a 4. 7 / 5. 030 inch bore, a 3. 58cc chambers, same effective CR as 64cc iron heads. I'v been getting different answers. 7L TBI compression ratio? 05-17-03 04:36 PM - Post# 231573 In response to scrambldcj8 Whats up! Yes the heads are 64cc and combined with the factory 10cc dish pistons the compression ratio is 9. 1957 Bel Air. The cc for the piston is entered as a positive number on a -cc Dish or Flat top piston and a negative number on a dome piston. 5:1, orig. 1:1 (this will not work with iron heads and pump gas). 015 in the hole, a 042 gasket, and no eyebrows or dish is pretty close to 9. Not going to change pistons, just about everything else though Not sure what way to go. 5 ram horn exhaust 2. Powerpack heads. 44" (+) compression height of the piston 1. 0% going from 13:1 to 15:1. 028 you will bring the compression up to 9. Assuming a 4. 5:1 compression to make 435hp/435tq with a 234/238 @ . 042 Gasket diameter: 4. 039 and you get 9. If you want a bit less compression ratio, consider dished pistons, which are readily available. 028 gasket would get 10:1. Of course, the intake closing point of the cam has some effect on cylinder pressure and allows a little tweaking and the squish/quench clearance between the piston crown and the underside Jun 19, 2020 · On a street driven small block chevy with aluminum heads, what are the advantages or disadvantages of smaller (64cc) chambers versus larger (70cc) chambers. 1:1 w/ typical dish; close to 10. Mar 16, 2010 · You said: "Right now i have 64cc heads and a compression right at 9. 025" in the hole @ TDC, that plus a . 5:1 compression ratio is what you would have if everthing in the engine met blueprint specifications. r. The heads are off right now. 74" (throw from the center of the crank) (+) 5. 64cc, piston head vol. Your real compression ratio is probably much closer to 8-even than 8. The cam is a generic cam that companies like PAW and Summit sell with 218/224 duration, . Before you can make an intelligent decision, you really need to know the volume of that dome in cc's. com to get an exact figure. is 10cc is one point in compression. 0 Jan 1, 2014 · The smog 350s like that usually had a dished piston, around 8 or so compression, with the big chamber heads. 015 thin shim gasket was worth about +1. 041 thick gasket). 65:1 Sep 23, 2009 · I will keep everybody updated. This compression ratio calculator can be used to work out the compression ratio of your engine. It’s a hill and hole tractor tire truck. 75:1 range, but you really are going to have to crunch the numbers to figure it out. 560 = 9. OEM deck height is . 0. 83:1 compression, and the DCR is between 8. Those 76cc smog era heads are pretty much the worst heads Chevy ever produced for the small block. This is often described as a heart-shaped chamber that reduces volume while improving combustion efficiency. 2:1 for a 327 bored . Feb 3, 2015 · The 1969 350/255 with it's 9. If I go to a . 020" below the deck is about the norm. What I'm wondering is, can anyone tell me how much my compression ratio will change by going to a 64cc or a 58cc head. 4" Manley stroker kit, L92 heads w/Manley valves, springs, Ti keepers; Comp trunion upgrade; Bullet cam; FiTech Ultimate LS system; 1-7/8" Hedman Hedders; Transgo shift kit & 4000 Jul 13, 2005 · C1 & C2 Corvettes - Piston choice for correct compression ratio - I am trying to get around an 9. His point is with a stock deck height and the head gasket from the Fel-Pro gasket set I have, there may be enough room there to accomdate 64cc chambered heads while maintaining a ratio in the Aug 31, 2008 · I did the math a (a couple times) with the calculator below and came up with a CR of 9. Nov 10, 2020 · This is a tight shot of a 64cc combustion chamber in an iron Vortec head. 5 to run on pump gas? Apr 7, 2016 · <EDIT> David Vizard (and likely others) published a chart based just on the thermodynamics and ignoring dynamic compression ratio effects. 7. Check the changes in compression ratio if you enter these numbers, or use a . 7 thats saying that the motor is stock. 021" head gasket will give you a . 5:1 assuming the use of a 0. Mar 19, 2004 · I used the Dyno2000 compression ratio calculator. 5:1 w/ aluminum heads for 93 pump gas. Decking the block will raise compression ratio, but the improved tighter quench will improve detonation resistance despite the higher compression ratio. 1 5/8" long tube headers. 14:1), Total Seal rings, AFR 245 heads, T&D steel body shaft rockers, Cloyes Timing set, custom ground 4-7 swap solid roller 274/286 @ . I’d like to figure out what the compression ratio is with a set of iron 64cc cylinder heads but I’m at a loss since I don’t know anything about the pistons. 040 head gasket thickness - 76 cc head volume should give you a CID of 349. 6 aluminum cam 213219 454 468 at112 head gasket 041 eldabrock performer cliffs qjet 2. 36:1 64cc= 9. I'm right at 9:1 compression now and like it becaues it will run on cheap (yea, right) gas. Plans are to replace the heads with 72cc combustion chamber heads to reduce the compression a bit, but the question at hand is whether this will be viable with a suitable camshaft selection. 10. 480, rod length 5. 2:1 compression but it wiped a lobe. Apr 26, 2004 · What is my compression ratio going to be? vortec heads (12558062) Anyway, according to Smokemup. 1 compression using 64cc . Apr 27, 2015 · 9. Play with the compression ratio calculators and you will find out what the different specs do for compression. 548 compression height) Get your engine's optimal compression ratio and total displacement in no time flat! Just complete your engine setup, click calculate, and you’re on your way to maximum performance. What are the pros and cons of 64cc chambers with dished pistons versus 72cc chambers and flat tops? Sep 21, 2009 · I'm thinking these numbers are based off stock motors. 021 gasket. Also ran across an episode of Engine Masters doing a Vortec head swap and they said that raised compression to just over 10:1. 60 Camel Hump Heads 64cc (3782461), Blueracer Camshaft: Duration 230/230 @. 041 heads. You should be closer to 11:1 than you think. 3-1 1966ss, roller cam 355 c. 0 compression ratio on a 327 with camel hump heads. 8:1 Jun 22, 2005 · Is the 327 in a 1966 chevy pickup (stock) have lower compression pistons vs camaros ect with 10. 5 with a 76cc head (asumming a . 0055” flat (not angle milled) cut per 1cc reduction of chamber volume. 050" with . 0:1 with the . 3:1 compression ratio, with about 170 lb cranking cylinder pressure. Compression Ratio, go to the Compression Ratio Calculator to figure it. 64cc heads: What would be the likely resulting CR of switching to aftermarket 72cc aluminum heads and no other changes? Apr 12, 2010 · In the process of doing a cam install and heads change in my 355ci sbc. Jul 18, 2011 · If you go with better heads than stock chevy castings you will get much more power due the better flow and chambersyou dont need more compression. 1-1 compression in a 327. Jul 5, 2005 · The heads are Dart Iron Eagle's Cast Iron with 200 cc runners and 72 combustion chambers. Mar 24, 2017 · hi I have 350 sbc bored 30 over dish pistons heads are 64cc 180 intake 202 1. 355s are at about 10. I found a compression ratio calculator in the knowledge base and the results are shown below. bore diameter 4. 2003 LQ4/4L80E. 050, . Is there a possibility that he is off on his compression ratio calculation? Jeremy Apr 5, 2021 · '69 Camaro - 429 SBC Dart Iron Eagle 9. 100, cyl. 060, deck clearance . Bore: 4. Chevrolet also made 64, 68 & 72 cc heads. 5. Feb 14, 2024 · Yes, the tighter the quench, the less prone to detonation (of course valve to piston clearance MUST be checked as well) as the flame front from the ignition kernel/spark does not have as much room for pre-ignition so, you can actually run a higher compression ratio (based of course on piston to deck height, chamber volume, gasket compressed thickness, head material (cast iron or aluminum) Dec 1, 2007 · Now I need to pick some heads but want to end up with a combo that'll run on 87 octane if possible. 95:1 (this will work on pump gas, barely) and with 64cc heads it is 9. The heads are 64cc iron Vortec 062s with screw-in Sep 9, 2019 · The 1968 SB Chevrolet 350 CI engine in my 1962 Bel Air was rebuilt in 1969 with forged flat top pistons and 64 cc 1962 double hump heads, for 10. Jul 14, 2009 · I was planning to keep the motor at about a 9. 95 inches. That means that your actual compression ratio is below 8:1, as noted above. 010" under the deck. Click this link, scroll down, click on the Compression Calculator link. Staying at 64cc with a . The equation for the volume of a cylinder is (i. Detonation destroys engines. This round will be: 400 . 5:1. But the true compression ratio is closer to 7. Without knowing exactly what numbers you are working with I would hazard a guess and say that your set up is probably in the 9. Get accurate compression without the guesswork! Get your engine's optimal compression ratio and total displacement in no time flat! Just complete your engine setup, click calculate, and you’re on your way to maximum performance. Rialto, CA 92376, USA +1 (310) 361-0020. 0 and 8. 5 with 76cc will give 9. I'm pretty new to this so take it easy. Cranking compression is 210PSI, which is OK for pump gas with aluminum heads w/ good chambers. 010 inch below the deck, and a 0. The block already has flat top pistons. Sep 24, 2015 · The key is in the heads castings ending with 193 are the high compression 64cc TBI head. That is clearly race fuel territory regardless of the cam you use. 57 to 1 compression ratio. compression calculator Re: 5. Feb 7, 2006 · W/ 64cc heads, your 357" sbc motor would be close to 9. These are the Dart Iron Eagle platinum 200cc heads with 72cc chambers. Dec 8, 2021 · Just something to consider when selecting cylinder head CC and head gasket thickness for desired compression ratio and quench. 25 Compressed gasket thickness: . 010 in the hole +. A much easier way would be to use an on line compression ratio calculator. 305 cc 186 heads was a premium fuel engine. The cams below is what I will be using. 025" deck measurement for comparisons of . 020 pistons for my 400, Compression is suppose to be around 10. 25:1 and I can run on pump gas, but has to be premium, and I have to watch the initial timing setting. 5:1 for use with aluminum heads to help prevent detonation. Apr 20, 2018 · Found a post on another forum that says compression ratio is 9. Nov 19, 2008 · Ok lets look at it a bit, theres two types of compression ratio, static and dynamic, keep in mind its MOSTLY dynamic compression ratio, that effects your results. 60 exhaust valves with Crane Golden Roller rockers, stud girdles etc. It has flat tops with valve reliefs. 88:1 compression ratio. 5 compression? Someone has added 1970 186 fuelie heads (64cc). Your effective boost compression ratio, reflecting static c. It appears that the heads on my 283 aren't the originials and we discovered that someone has had this motor apart before as the crank is already turned . 7:1 with no other changes. 4:1 with the . 5:1 my friend has a set of 492 Chevy heads (also 64cc) that has been shaved 60 thousandths I can get them for a song. 8 compression ratio. 0 to 1 . Putting in a flat top piston will get you around 9 something, and if you mill the heads a little and use the steel shim gasket, you'll get to where you might have to put good gas in it, assuming the cam isn't too big. 030 and deck the block to 9. 75 stroke afr 195 aluminum heads With that much difference in chamber size the engine's would not be truly identical even if compression ratio Apr 12, 2005 · "327 flattops and 64cc heads should yield about 9:1 static compression" I seem to remember the compression ratio of the '60's 250 HP & 300Hp 327's was 10:1 or maybe even 10. Simply fill in the form below to calculate your compression ratio. , cam timing, altitude, and boost of PSI is 8. How much compression will I lose switching to 64cc chambers?. Even with a 268 cam it will be under 8:1 dcr. Edl Air Gap,130GPH Holley mech fuel pump,ARP head/main studs,7/16 rod bolts,Tremec TKO600 5 speed with . We are among the largest LS and Gen 5 LT1/LT4-specific shops in the country, and we machine and assemble all of our engines, camshafts, and Precision Race Components cylinder heads in house! We also have a complete line of Texas Speed & Performance crankshafts, connecting rods, rocker arms, long tube headers, exhaust systems, and more. If you Do not know your current . 35:1 9. Mar 31, 2005 · Pro Comp Aluminum Heads, 190 cc runners, 64cc chambers, dished pistons. Nov 24, 2006 · It sounds like you're trying to max out compression with what you have, but SBC heads are so cheap these days that finding a 64cc chamber performance head is like falling off a log its easy. Looking to increase compression to 10:1 either will small chamber heads and factory dished pistons or to change to a flat top piston and 64cc heads. 488/. 4:1. 050 Lift 480/480 109 degrees Nov 30, 2012 · Now take the engine with 12cc dish pistons and change the heads to 64cc chambers will have 10. 72cc heads makes it work. 64cc heads. Oct 3, 2014 · My car has around 9. Aug 13, 2006 · like 8. Lars Jun 5, 2020 · 9. if you deck them . 060 with . Good rock and roll music should corrupt the young, it should corrupt them enough to think for themselves. 5:1 comp. 0 dynamic compression for a street car. 030" over 350 is running old camel hump 64cc heads, with flat top pistons. However, eh doesn't have any printed material about the pistons. 11:1 CR If you run same number with 58cc head: 10. This cylinder head includes your choice of 64cc (In order to retain stock compression ratio on 1970 and earlier small-blocks) or 70cc combustion chambers and high flow intake and exhaust ports. 7 rollers,7/16 push rods,Straub Tech custom Hyd. A flattop 406 with 64cc is about 11:1. 6. To help you determine the proper milling specifications for factory heads on popular classic V8s, we’ve included the chart below. AFR does make a very effecient head but that and 91 octane will only go so far. that cant be right since they Apr 6, 2007 · my engine shop worked out that with my flat top speed pro's with 2 valve reiefs cut in and zero deck, 64cc heads and . 31 = 9. 665:1 350+. 465 lift, 114 LSA. Sep 6, 2021 · With a 76cc chamber head on a 350 Chevy, your compression ratio will be around 8. 50ratio,DM rear adj. 025" so that would put you . youll gain about 3% in hp increasing the effective static compression ratio one full point, so swapping from a 9:1 to a 10:1 cpr boost torque about 3% The Edelbrock #60909 Performer cylinder head is designed for 302, 327, 350 and 400 cid small-block Chevy engines up to 1986. 0:1 with a 76cc head and . The 9. 1:1 compression which ruled out heads with 64cc chambers but my friend is saying this might not be the case. I'm about to purchase one of the two cams for my build. 1 compression ratio,, how many out there have run this on the street with aluminum heads and 91-93 octane pump gas with no problems. With the 59-60cc chambers. 0173- amount needed to mill intake ends for correct alignment and Feb 3, 2015 · The stock 307 compression ratio was advertised at 9:1 with 69-70cc heads, but it actually came in a little low with typical stock deck height in production. I will be putting on a fresh set of aluminum pro comp 64cc heads. these heads do crack if over heated but this Sep 13, 2002 · Also keep in mind that the 8. But before you yank the heads off to find out, you can just use the C/R calculator from the link below with an assumed . Aug 29, 2012 · 64cc heads will give you about 10:1 compression on most 350s with flat top pistons. 5-10. 039 gasket. 0 is based on a standard . My compression ratio is 10. This is actually my second 400 sbc for the car, the first round was 400 with Vortec heads, Comp 280H cam, 9. 5:1 with 64cc heads and flat-tops with valve reliefs. Those same heads are dyno tested on a 355 with 9. how much hp am I leaving on the table with a flat top compared to a dome? only thing I really worry about with more compression is the tuneup, as there is really no way to check the plugs between passes. 0123”- amount to mill port sides for correct alignment and sealing for each . 015 to 0. You need to know how far down in the hole (or out) the piston is @TDC. Jul 20, 2005 · Moving to a 64cc head would put the compression ratio around 9. The block is casting number 3849852 The heads that are on it now are 3917293 which apparentaly aren't the This Calculator is designed to tell you how much you need to mill your heads to achieve the . 60 exhaust valves the engine has a slightly more aggressive than stock cam and i'm hoping for a tad bit under 9:5:1 compression so i can run 89 octane Jan 6, 2016 · Keep in mind, milling changes the relationship between the heads and/or block and the intake manifold. Feb 18, 2017 · No - your advertised compression ratio is 9:1. If you had too much deck clearance you'd probably need to run . More than 10to1 comp go with aluminum heads. 020 inch below the deck surface. SBC 64cc Chamber. 7:1 and DCR 8. 5 to one right from the factory. 48 inch stroke, a 64cc chamber, four-relief pistons (about 6cc), with the piston about 0. With a good cam that should wake up the pathetic power of the current engine. The intake is a Performer with a 600 CFM Carter Competition AFB. 510 lift 9. 025" and for flat-top pistons from a -4 to a -6 or 7 cc's to allow for valve notch volumes. 7:1". best gains to be had on a small block Chevrolet is in the heads. Feb 9, 2005 · On the 11. 8:1. Do i keep heads for compression. 7:1. 5 to 1 if it was zero deck to your piston. 041 inch compressed thickness head gasket, the compression ratio would be exactly 10. and the 64 cc will raise the comp it just depends on the pistons, head gasket thickness and if the block has been decked or even if the heads have been decked,or if the piston is in the hole or has been zero deckedit all adds up in the end Jan 1, 2002 · On my currnet combo, switching to 64cc heads and a . 480 stroke - . But if I’m leaving a lot of power on the table I would consider going to a dome. program. . May 29, 2006 · Thinking of swapping my 76cc heads on my 406 SBC to a set of Vortec 64cc heads. I’m sure there must be a way to do this. i. 050" on 112 LSA roller cam, RPM Airgap intake and a 750cfm carb. 15-1). 190 Deck Clearence: . I really want to use the vortec heads and create a buildup similar to the "Impersonator" 406 that CHP built. 325" block, Crower crank, Crower 6" billet rods, Ross pistons (10. Is this compression ratio good for the street without using any special gas? Thanx in advance. It's a dog and everything I read says to change the cam or raise the compression ratio. Thanks! Nov 17, 2013 · C3 Tech/Performance - trickflow head for low compression 350 - I have the 260hp Goodwrench 350 that I am going to install this winter. 046" quench, then you have to take the +3 Jan 17, 2020 · Looking to put 64cc heads on my 327 SBC. Jun 21, 2007 · Question:I am building a 355 Chevy for the street using aluminum flat-top pistons with valve reliefs that at TDC sit 0. Jan 13, 2025 · We used the online Summit Racing compression ratio calculator to estimate your static compression ratio. any suggestions? Mar 15, 2008 · Have not purchased anything yet, really wanted to stay with the Eagle competition 400 assembly, B12501 -5cc pistons ( 11. The pistons are almost always a little further down the hole than the factory prints and the cylinder heads are almost never at 76cc. What type of compression ratio am I looking at with this set up? Any suggestions for thinner head gaskets to keep my cr up? Oct 3, 2008 · here's a little more information on his set up. 039 gaskets and a little over 7. Goal is to have it pull to 6000 rpm run low 13's. Cyl. 7 with a 64cc heads and around 9. PS. Dec 11, 2011 · Hello Chuck, the cam timing versus static compression ratio chart was taken from information provided by Crane Cams engineers. 060 Stroke: 3. What will the compression be with the 64's? Apr 27, 2005 · I'm exactly using Federal Mogul Sterling 345 np's with four valve relives + Edelbrock 64 cc heads and 0 deck. Assuming the same compression ratio, runner size, etc, is there a horsepower or torque advantage one way or the other. 550 lift Crower cam 234/244 @ . head vol. 2:1 cr with 64cc heads if the piston was only 0. 58cc in heads=9:5:1 compression. Notice how the chamber pulls inward between the intake and exhaust valves. 5:1 with the 64's. 3:1 Is this SCR too high (here in Europe we have 93 and 95. 63 compression with 64cc heads. 000 stack, a standard sbc block is 9. Say you have a core with 76 cc heads. 018 gaskets, which is basically saying your cam is too big for your combo, or your compression is too low for that cam. 33 cc 441 heads was a regular fuel engine. You will. What is your camshaft? it will make it or brake Feb 20, 2005 · I am going to build a 400 SBC w/dished pistons my compression w/64cc Vortech heads came out at 9. , 3 Apr 11, 2010 · i looked at the website and speed pro makes decent hyper pistons, but here's the math 3. I had to bore the "standard" block out to . 010. You want to shoot for around 8. need the actual compression of your setup now to complete this calculation. Period. 030 piston so if you want 10. Nov 13, 2017 · If I enter these data into CR calculator, for 64cc heads I got SCR 10. Mar 13, 2004 · compression ratio = 49. To use pump gas with iron heads safely you would want the compression ratio to be around 9. Installing a mild Aug 15, 2007 · Aluminum helps a tad too. gvlzmb eqahvbf umjud wujz wjeqaj dby abxvj nejwpn srgzsdg ygyh nflb mztp wfvda ydnk iycsg