speez302

I have a '94 Pro SOHC and was interested to see if I could raise to compression ratio by shaving the head. If so, how much can be shaved off?

What kind of a gain can be expected with head shave, port match & polish, bored exaust manifold, 2.5" exaust w/ free flow cat, RX-7 VAM, & bored intake?

jeremy

you should just swap in the lx motor ---its only 450.00 here is a link

http://cgi.ebay.com/ws/eBayISAPI.dll...474287103&rd=1

speez302

thanks but I really would like to retain the SOHC.

Protoss

i dotn see why, but it is your choice, if you want to raise the compression swap in a set of dohc pistons.

imho you are better off swapping engines, there is the same if not more work involved with changing pistons than swapping engines, believe me i've done it many times.

Protoss

if you want you can IM me via AIM.

Roddimus Prime

I know this is OT, but it goes along the same lines....

In the turbo ford circle I'm from the SOHC turbo motors are unstopable....a lot of people have converted over to the DOHC ranger heads and lost gobs of power. I think it's just so many parts are designed for the SOHC cam it will just make more power....this of course is only one example of why it's better to stay SOHC, but I think people put too much importance on DOHC motors....They both get he same job done it's just that the DOHC motor does it with twice the parts!

midnightblue97

That didn't make sense at all.

macdaddyslomo

umm yeah Rod...that really didnt make a whole lot of sense....try this on for size. DOHC motors are not necessarily more powerful than SOHC...but they are usually more efficient...and in most cases they have more valves...also a DOHC usually has more options in cam profiles, plus they usually are able to rev higher....in this case the DOHC protege motor DOES make more power and has way more performance parts. the swap is a better idea than upping compression by shaving the head or doing a piston swap. less work involved, and cheaper too.

Roddimus Prime

I agree the swap would be better.....what I'm pointing out is that DOHC is not ALWAYS better than SOHC. In the case of the turbo fords an 8valve SOHC can have much larger port sizes. It's basically just a way to get air in and out.....some people prefer to have 4 smaller ports and some 2 larger ports. Also, the 2.3L sohc ford motors can easily rev up 8K with proper valve train. I know the DOHC 2.0L is a good set but Wagner and I are shooting for 8K rpms with my RACE NA cams and all new titanium valvetrain.

I do agree that a dohc motor is typically stronger throughout the powerband where the sohc motor has to be tuned to run in one primary range.

I guess what I'm trying to say is: Corn is good isn't it?

= )

macdaddyslomo

lol, yeah that makes a bit more sense. just to point out "it's basically just a way to get air in and out "....isnt that how you make more horsepower on ANY engine...moving in and out more air.... ..just screwin with ya....so the AEM is gonna allow you to rev to 8K ? gonna get a big ricer Monster Tach too ???

Roddimus Prime

the AEM doesn't make it rev that high...the valvetrain does!! The AEM just controls the rev-limiter! I'm also not going to go that high on the stock internals.....I'm doing it from the ground up....I want this motor to last!

itzkcatz

Thats a 95-98 es bp also, Might bew different to just swap in a first gen. I would upgrade to the Dohc. Or put the Dohc head on your Sohc engine.

midnightblue97

Jon, you know what everyone says about swapping the dohc head onto the sohc block.
I'm not an engineer by any stretch, but from several different posts and shiut that I've read, ther sohc head is a really crapp design and not a very good base for performance, even with extensive head work.

UCSBgeek

http://www.billzilla.org/2v4v.htm

Roddimus Prime

what a good read. He's obviosuly more of an engineer and not a mechanic!!