Head Swap.. 452 to Trickflow

[Big Sugar]

Hey guys

Looking to swap out my 452's for a set of Trickflow 240's. Just have a couple of questions.

My 440 is .30 over has SRP flat top's with valve reliefs they are sitting about 12 thousand below deck. was told by builder the motor was 10.5:1.

Will I have any issues with the dramatic drop in CC's ? (452 88cc open chambe)r (trickflow 75cc )
( My 452's have been Ported and polished and quite possibly shaved. But I don't have the build info.)


What gasket thickness and Brand should I be looking for ?

Do the heads need to be re-torqued after a heat cycle or a few hundred miles ?

 

[Garys1969RR]

Your C/Ratio is going to be around 11.5 to 1 with the 75 cc head, and a .040 thick head gasket. The fel pro 1009 may be right for you, its a .039 compressed thickness. That would give you .051" of squish which should work well.

- - - Updated - - -

The calculators show your current set up at around 10.2 to 1 C/R, taking into account that your pistons have 5 cc of valve relief in them. Check the K B C/R calculator, it is very helpful.

 

[Big Sugar]

Gary

So When I pull the heads should I reconfirm the piston top depth before ordering my gasket ?

And should the heads be re-torqued after a heat cycle ?

 

[Garys1969RR]

Yes its always good to confirm your piston to deck clearance. If you are using an aluminum head, then you can't use the .020" thick steel head gasket. That leaves you with the .039 and thicker options. I don't normally re torque my head bolts. My iron headed 451 has been running for 3 years now with no issues. .020 steel shim gasket. There is also a perma torque head gasket that isn't supposed to require re torquing. IQ 52 seems to like the 1009 fel pro, and I'm sure that one would work well for you.

 

[IQ52]

And here I thought I like to use the 8519PT1 for everything up to 12:1 and I used the 1009 after that. I guess I just forgot.

 

[Garys1969RR]

Oh so that's it. I guess I forgot. Good info there. Thanks for clarifying that.

 

[Pysyko]

Hey Big Sugar!
Please confirm with Garys1969RR and IQ52...
But if your previous heads were shaved, there is a possibility your intake has been shaved as well...
I remember seeing in a DC book... 0.012 off the intake for every .010 off the heads?
Please verify my thoughts... It's been a long time & I am only suggesting you check...
I don't want to you to have any weird issues after getting your new heads on...
Good luck with your engine!!
I am thinking I will eat mac & cheese a few more months and then try get a set of trick flows as well...

 

[Big Sugar]

Cheers Thanks for the Reminder !