Deepa

I am about to install cam/heads/timing chain/cover or my 91 L98.

I have a new set of ARP head bolts, new felpro head gaskets, and will make sure the gasket surfaces are perfect and clean.

I have read about using sealant on the head bolts. The bolts from ARP seem to be coated in oil. Should I clean them before I put the sealant on?

More importantly, which sealant should I use on the head bolt threads? Do they all need sealant? I have the factory manual for torque sequence and foot pound values.

As far as the timing chain cover, I bought a new one from summit. I also have a new fel pro one piece oil pan gasket going on. Which order should I install them? The timing cover has a U shaped groove the gasket fits in. I have heard of people grinding the 3rd side of that loop so it can be removed without messing with the oil pan gasket. Any ideas for me?

After I get the heads on, I will be able to measure the pushrod lengths. I do not know how to do this. I have the measuring tool. Its an adjustable pushrod to get you the correct size. Just need to know how much preload to use on it etc etc. I have the GM performance hydraulic roller lifters if that matters.

Thanks,

Mike

JAKE

Here's a link to a site with the procedure to determine the correct pushrod length. It's absolutely the BEST one I've found in all my reading. Although there will probably be different (sometimes over the top) recommendations, the procedure in Circle Track magazine is the one I use.

http://www.circletrack.com/techartic...gth/index.html

Yes, you need thread sealant on all the head bolt threads and, also lubricant under the heads of the bolts and washers. Use ARP lubricant since you're using their bolts. It'll give you the most accurate torque readings. Follow the sequence shown in many of the manuals and use at least three steps, then go over all of them on last (4th) time.

Be sure to use a steady, even pulls on the torque wrench. No sudden, jerky pulls.

I'm not in favor of modifying the timing chain cover, the T/C gasket or the oil pan gasket. My thinking is the engineers designed those to minimize the possibility of any leak, so, to me, it's not worth the risk.

When it comes to how much preload, you'll probably get responses all over the map. Many use LESS than the recommended amount (which is one full turn or, in the case of my 96 LT1, one full turn +/- 1/4 turn) then end up with a noisy valve train and in a few cases valve train failures. The failures often occur when the self-aligning rocker arm(s) jump off the valve stem tip.

Hope this helps.

Jake

rpoL98

you need to rinse the head bolts with solvent. I use brakleen. oil doesn't help the teflon thread sealant.

i also use brakleen to rinse the threads in the block after i've chased the threads. again just to get a better seal against the water jacket.

the oil on the bolts is to prevent rusting. I'd recommend that you spray-paint the bolt heads for the lower row of head bolts with engine enamel to prevent rusting. the ones that are below the exhaust ports. the others are bathed in oil so they're preserved.

Deepa

Jake, Thanks for the pushrod article. Explains a lot.

RPO, I'll throw a quick coat of paint on them.

What kind of thread sealant has worked well for others?

Deepa

I bought the permatex high tack thread sealant.

http://www.permatex.com/products/Aut...et_Sealant.htm

Will this work well for the head bolts?

I have ultra gray in stock at home, and I bought some of the right stuff also.

I do not want to do this twice, so any input on the sealer would be great.

Thanks,

Mike

rpoL98

for threaded sealing with water jackets, for the bolt threads, I prefer a sealant with teflon, like liquid pipe Thread Sealant with Teflon.

GREGGPENN

During my recent engine build, I found the one gasket that remained a paper style. If it's the same for you, it's the timing cover gasket. Everything else in the motor is rubber, rubber-like, or rubber coated.

The recommendation I got and will pass on here is to soak/coat any paper gasket in silicone. I just squirted some out of a tube and rubbed it into the paper. You'll clearly see it soaking into the paper.

I do this on wax paper so it won't stick. You can do both sides at once. Wipe off ALL of the excess silicone to prevent humps/bumps in your gasket.

I got this idea from my builder who'd observed the timing gasket to be one of the few he had trouble with. Over the years, he'd come to the conclusion that oil "wicks" thru paper gaskets. By coating anything that's paper with silicone, you prevent that.

IMPORTANT: Make sure you coat the EDGES of any paper gasket too. Otherwise, oil could still wick from edge-to-edge, in-between your silicone sandwich layer.

ddahlgren

Jake the article is interesting and old news for me but as you and they say to use a hydraulic lifter and turn the engine over what do you do about the collaping plunger as there is no oil pressure to hold it up. On another thread I remember also seeing something quoted that the proper preload for the LS lifters is 0.070 but may be wrong, but is that is correct the proper turns would be 1.7 turns with a 3/8 stud and 1.4 turns with a 7/16 stud as they have a different thread pitch.
Any thoughts?
Dave

355tpipickup

subed for my head cam swap! where can i find torque specs for this swap? sorry not tryin to jack the thread.

Deepa

what year and what torque value do you need?

Cam sprocket bolts call for 20 ft pounds in the service manual for my 91.
Head bolts are 67 per the manual, 70 per the AFR instructions.
Lifter guide holder calls for 12 foot pounds.

My cam install went well. I needed to jack the motor up 1/2 an inch to get clearance. I may have been able to force it out but there is no way i wanted to damage a bearing.

I ordered the incorrect timing chain. Cloyes part # 9-3100 was for the non hydraulic roller cams. Cloyes part # 9-3145 fit perfectly and i installed the set today. OEM crank timing, cam sprocket at 12:00, crank sprocket at 12:00, cam dowel pin at 9:00. THis puts piston 1 at TDC on the compression stroke. I went and rotated the motor so the dots were aligned at 6:00 cam and 12:00 crank to make sure I was not one tooth off. Now that my cam is timed correctly, i can go and get my timing cover installed and oil pan.

I just have to make sure I get the cam dowel back to 9:00 to make sure piston 1 is at TDC compression stroke. Not going to be fun when I can't see the cam anymore. Gonna have to be precise when I rotate the motor so the pan clears the counter weight up front.

I am hoping to get the intake on the day after christmas. i need to figure out pushrod lengths at the moment. Gonna read up a bit and that link above. It seems like the stockers are too short for my application.

219/219 cam, tpis cnc'd afr heads, scorpion 1.6 NSA roller rockers, gm perf hydraulic lifter.

I need to figure out preload for the lifters. I was thinking 1/2 turn. Does this mean I get the rocker tightened down so there is 0 free play between the roller tip and valve tip, then tighten another 1/2 turn on the rocker bolt?

Thanks all.

Mike

GREGGPENN

Kinda hard to imagine you'd really want to tighten LS7 lifters to 1.7 or 1.4 turns (depending on your studs). One full turn is probably the most you should consider....maybe 1.25 turns with 1 3/8" studs.

For heads, you can use the AFR rating for torque over factory rating for lower quality bolts.

1/2 turn preload does mean 1/2 turn past zero lash (no free play).

I recently saw a post with this interesting recommendation...

1/4 turn if you race and will recheck after races.
1/2 turn if you'll recheck once/yr
3/4 turn for a 2-5yr recheck
1 full turn if you never want to check them again.