Need to lower compression!!!

[xYoung347x]

I have a 347 Stroker motor 9.7-9.8 compression with AFR 185 heads (don't know what CC I got) and ported Edelbrock RPM. What other heads thats out there will lower my compression? I've been trying to sell my motor to get another one with a bit lower compression so I can start on my single T70 turbo. I guess I just try to lower it as much as I can with this motor but need some help.

 

[mstangfrk95GTS!]

thicker head gaskets?

maybe have some one do some bowl work on the heads

if they are 60 cc heads you should be ok as long as you dont go over 10 lbs or so on the boost

 

[VIPERn94Five-0]

thicker head gaskets?

maybe have some one do some bowl work on the heads

if they are 60 cc heads you should be ok as long as you dont go over 10 lbs or so on the boost

why not some low comp pistons??....no use in selling a perfectly good motor and buying a different one with lower compression...


Anthony

 

[yellow5.0cobra]

YOUNG.

I told ya, you will be ok till 8-10psi, depending on inlet temp, which you will have to monitor by some sort of temp device to keep safe.

Or you can do it the EASY way, rip the heads off and open the combustion chambers ~3cc's, then get a slightly thicker gasket(not the most recommended thing to do)... and you will more than likely see 9:3:1... and that is plenty to work with, well BETTER than 9.8.1.

come to think of it, my cobra which is 9:8:1 from factory has put down 422rwhp with 8psi thru a blower, and i had plenty of air fuel to work with(i was still rich as a pig). also one of my friends got a cobra and hes planting close to 500rwhp on stock bottom end(97 cobra).

but all in all, you will be OK with your motor, just dont look for 15psi!

10psi(turbocharged) should be making damn near 550-600rwhp on a 400hp 347 combo(assuming that is what it SHOULD be making +/- 15hp)

 

[moneypit94]

Hey i got a set of thick (.060) copper head gaskets you could try... They are slightly used but copper head gaskets can be reused multiple times..

my pistons are supposed to be right at 9.69:1 and im pushing 10 lbs of boost with my supercharger... I run 91+ octain in it all the time.

 

[4Jenna]

8-10 psi will only satisfy you for so long. If your doing something that serious (347/T-70) you need to build a ideal setup to get the potential outta it.
Start with a real block (don't know what you have), then shoot for 8.5-8.8 comp. Otherwise it's a matter of time.

 

[mo_dingo]

8-10 psi will only satisfy you for so long. If your doing something that serious (347/T-70) you need to build a ideal setup to get the potential outta it.
Start with a real block (don't know what you have), then shoot for 8.5-8.8 comp. Otherwise it's a matter of time.

But you are on the right track. Porting the cc's and thicker head gasket should be enough. Just do the math before hand.

If need be, you can swap out to dished pistons.

But if you block can't take it, doesn't matter what comp ratio you see, it will still split.

Give us some info on the bottom end combo.
Scott

 

[xYoung347x]

bottom end is stock with a main girdle, Im already making close to 400rwhp so I could only squeaks out like another 100rwhp.

 

[yellow5.0cobra]

exactly my point... 10psi will definantly knock 100rwhp out of the 347.


READ MY DAMN POSTS!!!!!

 

[xYoung347x]

I hear ya Pete, sorry for getting your blood pressure up. Starting the project once I sell my long tubes, get some headers, and some tubes from summit.

 

[yellow5.0cobra]

lol...

who is paul?

im pete.

and nah, i was kidding... just bored... no blood pressure problems here.

 

[xYoung347x]

thats right Im sorry, I was mistaken you for someone else. SORRY

 

[xYoung347x]

Well actually your name slip out of my mind, I knew it but all the damn fireworks knock some brain cells out. Anyways hows your turbo coming along or did you updated on some other post? let me know, Im always interested in your work.

 

[yellow5.0cobra]

any updates... hmm... possibly tomorrow i will have some pics of the downpipe for ya... or at least some pics of the during process of it being hacked and what not.

gotta pick up the cam from my buddies house asap to get it uploaded.

if i have a big enough paycheck on tuesday i will call up summit and order a bunch of u bends and get a header flange from someone and some small tubing and make a a/c compatable version. if not this week(hopefully) then in 2 weeks... because im on a tite schedule with my 94!

 

[xYoung347x]

Thats great, well what side are you gonna put the new turbo project on? if you were to keep P/S and can loose ac which side would you recomand putting the turbo on?

 

[yellow5.0cobra]

i would still throw it on the driver side just for the hell of it.

lots of the easy to come by intercoolers have a LEFT in and a RIGHT out... the rare intercoolers have both inlet and outlet on the same side.

so i mean.. its a cost factor thing... you can pick up a nice sized intercooler that is generic for about $250, but when you have to modify crap for it to fit... then ah its not worth it.

but ya driver side is cool with me...

also no problems with heat soaking the intake pipe tract, becasue believe me, it gets DAMNNNNNNNN HOT.

so tubing goes out oneside of the car and in another side, and the air most likely gets cooler because of travel anyway.

on the new a/c compatable project i will put the turbo on the driver side and see what happens.



but as pictures show above, my current setup stays as it is till i finalize the a/c compatable setup.

 

[xYoung347x]

well theres one problem you solved for me.