americanmcss

Finally got around to checking my compression yesterday and was shocked to see how high it was (180-190 in all four). I read my haynes manual and it said that above normal compression could be caused by excessive carbon build up in the combustion chamber. I wouldn't be suprised at all, although It doesnt burn any oil, and the engine runs great, and gets really good milage for what it is.

Im thinking about replacing the head because Ive got some bad exhaust manifold stud situations. The front bottom stud is completely broken off, and the two top ones have slightly stripped threads. I went to a shop to get a quote for an extraction and helicoil, and they told me to expect around $200. I can get a new head shipped to my house for that kind of money.

So if I were going to take the head off (1987 4x4 w/ 22re) what are some of the tips and tricks to do it. Are there any mistakes you guys have made that might make it a little easier. I've got the haynes manual which I know isn't the greatest, but its better than nothing, and a good buddy of mine is a somewhat competent mechanic and he would be helping out. I know that labeling vaccuum lines and hoses and taking a lot of reference pictures and of course separating hardware, are all 110% important. Anything else I should know before jumping into this?

corax

180-190 isn't really all that high for compression. Have you thought about drilling and heli-coiling the head you have on now before you just yank it off? You're gonna have to remove the exhaust manifold to yank the head anyway, so you might as well try before you go to all the effort of putting on a different head. Just make sure you use a NEW sharp drill bit and make sure you're centered before drilling the old stud out. Helicoils are cake once you do one.

BTW, I'm not sure I would trust a $200 cylinder head.

Ezrider_92356

here is mine at 6k miles after rebuilding my motor



nothing to be concerned about as long as its even all the way across

bobby_duce

thats what i was told along time ago from a master mechanic and thats what ive always gone by and its never failed me. he said its better to have them all about the same even if it seems "low" of corse within reason. its better than having 3 out of the 4 high and one low cause that could be a sign of internal problems.

sb5walker

Higher compression gives you the potential for a bit more power, but in practice may make the motor more prone to detonation. If the motor has a knock sensor (I understand some 22REs don't), then the computer may be pulling back the timing, which will reduce power and gas mileage. So with any motor that has higher than spec compression, it's best to burn higher octane gas, at least 89 octane rating. Also it's more important not to have lean running, so make sure injectors are all clean and flow is balanced between them. Otherwise some cyls will be leaner than others, which puts exhaust valves at risk. Also important to have a good functioning EGR to keep combustion temps down.

EDIT: If you think there may be carbon build-up, feeding some water into the intake will help clean it up:
https://www.yotatech.com/forums/f116...l#post51124041

Yes, water really does work: http://www.files.thinksitout.com/Alt...f%20engine.pdf

Moonfish

In my self education about outboard motors, I've read repeatedly that you don't really read a cheap compression gauge for the exact number but look for uniformity. You can check them cold and get one reading, a different one with a bit of oil and another one if the engine is hot.

If you read about other people's exhaust manifold fixes, I think they ran a 5/16 tap in there and used a 5/16 stud of some sort.

americanmcss

Why do you say that? Its a remanufactured original head with new oem valve train parts (no cam). Its no high performance head but its up to oem spec.

americanmcss

Well I have heard that 180-190 is relatively high since all the research I have done says that 170 is normal. Im not getting any detonation, which is nice and it does seem to have a decent amount of power and gets 22mpg.

Im not too excited about doing the extraction myself...I tried it once with a mopar head which was out of the car, and ended up breaking the easy out in the hole. The machine shops even said they couldn't get it then. I may end up trying I suppose, since I really dont have much to lose anyway.

xxxtreme22r

I agree, EB's heads are great, have not yet seen anyone have a problem with them. Myself included. His bare head is $248. Complete ready to bolt on with OEM sized valves: $348. This is all including shipping.

JamesD

Are you using a cheap compression gauge set? If so I would check it against another.

James

americanmcss

Not sure if you would call snap-on cheap, but id say its pretty reliable for the day to day guy...lol

corax

I just don't see that $200 would even cover parts, not to mention the labor to tear down/clean/inspect/reassemble a cylinder head. You get what you pay for is all I'm saying. If the company has a clean reputation for that price, then I stand corrected.

Team420

If you are concerned about carbon build-up.... Why not do the seafoam trick? Maybe time for a valve adjustment? Honestly tho... I wouldnt be too concerned about those specs, as long as they are all within 15psi of each other... Should be fine

Marc

Doesn't mean it's working correctly.
I'd try another for comparison.

shaunneuhaus95

also if u do the helicoil your self, do not use a carbide drill, use a hss drill there more forgiving on someone and wont snap as easily

Kaptain

I definitely wouldn't bother with a new head in this case. Just take care of the exhaust stud threads and go from there.

I would never pull the original head off unless absolutely necessary. I've come across way to many threads of the headgasket failing within 5-15k miles after removing it. For whatever reason it's just not the same (Gasket brand, not checking straightness of head\block, surfaces not 100% clean, improper torque...etc - too many factors involved).

americanmcss

Well Ive decided to try the helicoil myself but its still going to be a chore. Looks like im going to have to remove/reposition the power steering pump and its accessory structures in order to get a drill square on that hole. Im also going to try and sefoam the truck as well and see if that takes care of some of the carbon build up as well.