Reply With QuoteWhat size is the engine?
Right now my motor is 10.5 to 1 c/r with 95cc cylinder heads, and I can't find the paper work on the pistons(forged trw dome tops), but I was possibly going to run a cylinder head w/ 75cc and was curious if anybody could estimate what the c/r would move up to ? I know that without the piston specs that is a difficult thing to do but I was just looking for a guess or opinion. Also what is the formula to figuring out compression ratio ? Thanks.
What size is the engine?
Sorry about that , its a 466ci.BBF
Right now my motor is 10.5 to 1 c/r with 95cc cylinder heads, and I can't find the paper work on the pistons (forged trw dome tops), but I was possibly going to run a cylinder head w/ 75cc and was curious if anybody could estimate what the c/r would move up to ? ...its a 466ci.BBF...Thanks.76Miller,
If you have L2443-030's in your 466 with 95cc heads and wish to swap to 75cc heads, your compression ratio will jump to about 13.2:1, slightly more if your block is zero decked.
LO
Thank you for the reply, Its hard to say if the hp gains would be worth the race gas prices????The heads I was thinking of running were the P-51's. I know they flow really well, and the c/r increase will help w/ power but....what is your opinion?????
You will certainly make more power; how much more power depends on your cam and your overall engine combination. And a mis-matched combo might be little help at all.
Also, to run the P51's you will likely need new pushrods & new rocker arms (depending on what you currently have now), and most important to note is that the P51 heads have a relocated intake valve that will not align with the valve pockets in your dome top pistons. The valve pockets very likely will need to be notched for piston-to-valve clearance, let alone their needing to be notched due to the misalignment with the valve layout with the cylinder head you are considering for the performance upgrade.
The TFS 429/460 Street/Strip head would be a much better choice under your circumstances, with what little I know about your engine combo. You can always port the heads that you have and maybe change the cam.
LO
Lakes-
Thank you for the helpful info. I have one more question for you, what Ford block would you run for a 532ci. build ? It will be n/a, with a big shot of nitrous on it. If you could come to a price also, I will be needing one soon. Thanks for your time.
All of the Ford cylinder block castings (C8VE, C9VE, D0VE, D1VE, D9TE) are suitable for a 521/533 combo. How much hp you want and how you intend to get it will determine the suitability of the particular block and/or whether it should receive upgrades.
The addition of nitrous oxide warrants a 4-bolt main cap conversion. I am not a fan of running nitorus as I have seen first hand the additional stresses it places on engines including melted pistons, blown head gaskets, burnt valves, severe cap walk, etc. Further, most people that step up to the 4.3 stroker's find that they have more power than anticipated and are usually very happy with their build sans nitrous.
Blocks are in stock, $125 for a fresh teardown. Thermocleaned and magged blocks are also available, and also with Stage 1 prepped oiling mods as outlined on the Technical Pages (www.highflowdynamics.net) of our website.
If you were inquiring in regards to a quote for a complete 4.3 stroker build, then please call so that we may discuss details and more accurately close in on a figure.
LO
ive always been told that for every 10cc in the combustion chamber area,give or take that is good for 1 point in the compression,for instance with a 95 cc head going to a 85 cc that put you from 10.5 to 11.5,this is a rough estimate b/c of deck hieght bore size and other factors but i have found it to be pretty close.
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