does anyone know the compression ratio of the sohc 1.8 l engine

 

8.9:1

nice and low, good for turbo.

 

It's 8:1. You're not going to make good power with that, even with a turbo.

 

First Gen 9:1
2nd gen 9.1:1
10:1 or higher is fine for turbo, and not that difficult to achieve reliably with common sense and premium fuel, but then if you're going turbo you'll be using premium anyways.

 

thats for the dohc

 

What? 10:1 for turbo? Are you insane? FI is all about high boost and low compression. Boost is more efficient at making power than compression is.

 

It's not 8:1 ....

 

10:1 or higher is definantly not what you want for a turbo. You'd be blowing head gaskets and predetinating left and right. You don't want to go any higher than 9:1 with a turbo setup, exspecially if your planning on running a lot of boost.

 

Sigh.
Tuning is the Key.
Why do Top fuel cars run 14+:1 compression and have over driven superchargers??
If you tune properly and use high quality materials (IE headgaskets, rod/main studs etc..) you WON'T have problems.

 

Thank you my point exactly. The thinking of low *** compression with turbo is like 15 year old thinking. And my old '93 DX driver manual said the compression is 8:1.

 

Probably because they run ALCOHOL or NITRO fuel. Which is NOT street legal, nor available to you on the street. Plus, if you run these types of fuel, you have to change your oil every 5 mins.

Not really. Boost is MORE EFFICIENT at making power than COMPRESSION. Your engine can only handle handle X amount of pressure (X= boost + compression). Boost can be intercooled. Compression cannot. 8:1 + 10lbs boost makes more power than 10:1 + 8lbs boost. Once you understand that, you'll understand why every single (streetable) FI car uses low compression + high boost.

I have mine right here. SOHC: 8.9:1, DOHC: 9:1 compression.

 

hey the cars are old so the 8:9 ratio isnt going to be right so check for ur self

 

The owners manual says 8.9:1... however you should do a compression test to see what you're REALLY at.

 

Fine, believe what you want, but there are streetable cars with high boost and high compression. Its NOT that hard.

 

midnight, you are correct...high compression + boost is possible with proper tuning...using low compression on a turbo engine just allows for more error with fuel control...that is why tuners like it because most DIY guys like it, it's cheaper and easier, NOT better...why do you think more modern turbo cars run higher compression than before...fuel delivery systems are more efficient and can be VERY fine tuned..most cars though are 10:1 or less compression ratio anyway, unless they are higher end sports cars and are perfectly capable of running boost