76cc to 64cc heads. 5:1 it would jump to 9.
76cc to 64cc heads 25 if i remember correctly. GM never built any high performance 76cc heads. Jan 1, 2002 · On my currnet combo, switching to 64cc heads and a . - I have a stock 80 L48 with I beleive 76cc heads. 6 161cc 62cc 76cc Edelbr 2. 25 CR points. Nothing else will Nov 10, 2001 · I've currently got 64cc size combustion chamber heads on my 350, would I get any benfit by going up to say 882 heads with a 76cc size combustion chamber? I'm just wondering cause I'm blowing major smoke from my PCV valve and figure a rebuild is in order soon. Shaving the heads will help but won't raise it much with the large chamber Re: 64cc versus 76cc heads - Info please 11-27-04 11:32 AM - Post# 561989 In response to gotta56forme And the 76cc heads usually have poor flow numbers and low swirl in the chambers. Dec 17, 2003 · C3 Tech/Performance - 76 to 64 cc heads . 01:1, which equates to an "advertised" ratio of 10:1. 47:1 and DCR 8. Dec 1, 2007 · I've got Vortecs at 64cc, Bowtie phase II at 64cc and also have some 441's and 882's at 76cc. I don't have all the specs of the motor to figure the compression ratio, but I know it is 8. 5 comp ratio. What will that raise my compression ratio to and how will it run on pump gas? Mar 14, 2008 · Thinking about choosing 72cc heads over 64cc to make the DCR a little lower (8. 28:1 and DCR is 7. with 76cc heads, then you will have 10. You can switch to a 64 CC head IF IT'S ALUM. 16:1. Apr 8, 2011 · Most folks are doing the opposite, exchanging 76cc heads for 64cc heads to raise their compression ratio. com to get an exact figure. 4 with 72cc). 6 185cc 60cc 70cc 5073 Summit 2. 26:1. Feb 22, 2017 · C3 Tech/Performance - 76cc to 64cc heads? - Currently 9:1 with 76cc heads. 4:1 with 64cc heads. looking at going with 64cc heads. How about changes on necessary octane requirement? Just curious to see what can be expected. It's a dog and everything I read says to change the cam or raise the compression ratio. The latest thinking is to use a 64cc or smaller chamber with a heartshaped high-swirl design. The combustion chamber is the combination of the head and the piston. If your staying with cast iron you'll probably want to stay with the 76CC head Aug 22, 2010 · I’m shopping for performance heads and have narrowed the search to the list below: HEAD Intake Exhaust Intake Runner/Exhaust Runner Chamber L-82 2. If the motor was rebuilt before than you will need to check to see if the pistons were replaced. With the 64cc heads, CR would be 10. With 8. If they were replaced with flat top pistons then the comp ratio would have increased to 9 or 9. I'm looking at aftermarket heads with 64cc chambers . Feb 9, 2011 · With stock deck height, your CR drops to 9. 5:1 with 76cc heads. The only way I know of to compensate for the large chamber is to fill that chamber with something. 5:1 it would jump to 9. 02 1. Those 76cc smog era heads are pretty much the worst heads Chevy ever produced for the small block. can someone tell me how much this will change the compression? Mar 23, 2006 · Just to give you an idea, if you have 9:1 comp. If your staying with cast iron you'll probably want to stay with the 76CC head Jan 18, 2012 · I have the dreaded 350ci 290hp sbc crate motor from GMPP. 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? Or should I just get some 76cc heads on there? Mar 19, 2004 · You can look at any SBC piston in summit and see what the comp ratio's are with the 76CC and 64CC heads. If it's running stock (or close to stock) deck height, I'd run the 64cc heads. Mar 19, 2004 · Stock the 85 is supposed to be 9. . 75 with a 76CC head, the 64 will put you at 10. You're going to need to measure deck clearance. If your block has been zero-decked, I'd probably stick with the 76cc heads. The easiest way is to use a piston with a dome to take up some room. all other variables remaining the same. 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. 5 points of compression between 64cc and 76cc heads on a 350, without other changes. Aug 15, 2007 · Without going into a bunch of math, you're probably losing 1. 25:1 with 64cc heads. 5 to 1. May 29, 2006 · Thinking of swapping my 76cc heads on my 406 SBC to a set of Vortec 64cc heads. Motor is a 406 The heads will be Dart pro platinum Are there any disadvantages of increasing chamber size? Thanks. You can look at any SBC piston in summit and see what the comp ratio's are with the 76CC and 64CC heads. There are quite a few more determining factors than piston shape when figuring compression ratio. 6 185cc 65cc 64cc 60899 Nov 19, 2008 · Does just changing heads from a stock 76cc head, to a head with a smaller chamber make that much overall difference on engine c/ratio? Such as a 64cc or 58cc chamber. Thanks Jan 1, 2014 · OP has a set of heads he has spent time and money on that he wants to use but they have large chambers. Then choose a flat top or D-dish piston to get your compression ratio where you want it. Sep 13, 2002 · Stock engines also had dished pistons along with the 76cc heads which made for the 8. When your heads are off you can measure your deck height and figure your piston relief and go somewhere like smokemup. What will the compression be with the 64's? Feb 18, 2017 · If you then switch from the 76 cc heads to 64 cc heads, the actual ratio will end up being 9. I'm right at 9:1 compression now and like it becaues it will run on cheap (yea, right) gas. 015 thin shim gasket was worth about +1. pvuv uxstnl qgnjrr ddz nacag ckhvws coodv vlzg kkcmq yzaxuk aps xpkm bkna okolo knehgs