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Engine Rebuilt, almost no compression
Topic Started: Oct 26 2013, 06:18 PM (3,401 Views)
Frozen_Joker
Elite Member
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I still have the same compression with the retime. So I am beginning to wonder about this head gasket.
Everything else was good. And considering I am getting low compression across all cylinders, It would have to be something as a whole.
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Hydrojim
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What brand of head gasket did you use?
Edited by Hydrojim, Oct 27 2013, 04:00 PM.
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Frozen_Joker
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Fel-Pro. And I have never had an issue there. But I think I am now. Because I just now looked at some pics of different brands and Fel-Pro. Fel-Pro looked totally different. In fact when I lined it up it didn't look right having holes where there was no holes in the block. Also I noticed some of the holes in the gasket were A LOT smaller than the holes in the block.
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PTA2PTB
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I'm totally awesome! I swear.

Geo Glenn
Oct 26 2013, 08:55 PM
PTA2PTB
Oct 26 2013, 08:46 PM
IMO, the easiest - and surest, way to determine which of the two camshaft gear timing marks to use, is to reverse engineer it: start by aligning your crankshaft pulley's index mark with the TDC mark on your timing cover. Pull off your distributor cap and align your rotor with the #1 spark plug tower of the cap (you may want to make a mark on the dizzy housing with a sharpee before pulling the cap, to help pinpoint that spot). With your crank set to TDC, and your dizzy set to the #1 plug tower, now attempt to install your camshaft gear. Try both orientations. One of them should be spot on. The other, not so much.
:whistle PTA2PTB is banished back to the humor department. No distributor on a G13BB engine.

:smackface Oops, I guess I got my wires a little crossed there, and forgot what type of engine were were talking about. *PTA2PTB recoils at the thoughts of having distributed misinformation* :'(

I still think it's a timing issue - involving the cam, for the the compression to be that low, and on all cyl's, following a fresh rebuild. Since he has lash-adjuster rocker arms, it can't be hydraulic lifters that are too pumped full of oil.

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Frozen_Joker
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I have adjusted the rocker arms as per torque specs and everything. I have triple checked timing. Still the same compression.
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PTA2PTB
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I'm totally awesome! I swear.

Frozen_Joker
Oct 27 2013, 04:03 PM
Fel-Pro. And I have never had an issue there. But I think I am now. Because I just now looked at some pics of different brands and Fel-Pro. Fel-Pro looked totally different. In fact when I lined it up it didn't look right having holes where there was no holes in the block. Also I noticed some of the holes in the gasket were A LOT smaller than the holes in the block.
If you were losing that much compression, through all 4 cyl's, all that compressed gas would have to be going, somewhere; and be detectable.

Take your radiator cap off and look inside, while someone cranks the engine over. If you were losing that much compression through your headgasket, there's a fair chance you'll see bubbles coming up in the radiator. If not, it would have to be going into your oil galleys. Not sure how you'd go about finding it, butt if you open up a passage - somewhere, you should encounter an oil-fart; which would be a relief, to have, at least, found it, even if the thought of having to replace it, stinks.
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Frozen_Joker
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No bubbles from the radiator. And no fart from the oil cap or anything. The exhaust blows out the piece of paper and doesn't suck it in.
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PTA2PTB
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Did you "disengage the fuel injector wire harness at the couplers" (like you're supposed to), before doing the compression test?
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Frozen_Joker
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Yes sir. I torqued the head bolts down to 49Ft Lbs. Should I go further?
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Hydrojim
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is your throttle all the way open during the compression test?
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Frozen_Joker
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Yes it is Hydro.
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Old Man


can you post a pic of your cam to crank timing gear. try to include the complete gears.

sometimes I have seen experienced mechanics swear by their timing and even after they checked them (the same way each time) I have found the timing to be off. Sure would like to see a pic of your timing belt & gearing complete.
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Frozen_Joker
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That would require removing several things and lifted the motor high enough to get the shot. I left the time cover off for the time being so I didn't have to remove 20 parts just to retime. I have the cam gear set at this http://geometroforum.com/single/?p=295571&t=3519698, and the crank gear set at this http://ecomodder.com/forum/showthread.php/how-advance-timing-12617.html with the number one piston at the top of its compression. Scroll down to see the crank pic, that is where mine is at.
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PTA2PTB
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If it were mine, as an absolute last resort, before doing something more drastic, like tearing the head back off, I would:

pull the timing belt off
remove the valve cover
rotate the camshaft so the lobes are pointing away from the intake and exhaust valve rockers
test the compression on that cylinder
If it comes way up, you have a timing issue, involving the orientation of your belt on your camshaft relative to your crankshaft. If your compression reading stays the same for that cylinder as your previous test, then back way off the lash adjustment screw on both valves, so that there's absolutely, positively, no pressure on the valve stems by the rockers, and do the compression test again. If it still doesn't come up, then you have SERIOUS problem, somewhere. You probably will have to tear the head back off and investigate, if that turns out to be the case.
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Frozen_Joker
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I am tempted to do that anyway cause I am none to happy looking down into the oil galleys and seeing such a itty bitty hole. I will try timing it and re-torquing the rocker arms back down again. If I still have no luck, I am gonna start pointing my finger at the odd looking head gasket. Once it is timed again I will take a couple new pics of where I have it timed at and upload them. But I think for today, I am calling it a quits. This car is getting under my skin today. Lol.
Edited by Frozen_Joker, Oct 27 2013, 04:53 PM.
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