Dumb is as Dumb does (exaust valve / head gasket replacement)

Sometimes I wonder about my IQ

Managed to bend the exhaust valves on the rear bank. Happened while torquing cam pulley bolts.
Love making work for myself!!!
Will have the head off this weekend assuming I don't have to use a hand grenade to get it loose from the studs.

Any ideas on a solvent / prenetrant that will help. From what I've read it might turn into a real nightmare getting the head off. I'm not a machinist and don't have correct equipment to make a head puller as illustrated on this forum. If push comes to shove I can cobble something together but am concerned about making a bad situation worse.

So wondering about head gaskets. Anyone have experience with the Cometic MLS gaskets?

Plan on getting exhaust valves from Superformance. Any opinions good or bad?

Any cross reference for the valve seals or valves for that matter. I'm only planning on doing the exhaust valve seals unless the intakes are leaking and require disassembly.

Can the rear header with heat shields in place actually be removed with the cylinder head in place and not jacking the engine up and forward. I have mine completely disconnected along with the e-brake and I can't figure a way to get it out of the car either from the top (obvious) or the bottom.

It appears the only way to remove the heat shield is to cut it off?

Rather than cut the heat shield off I may just replace the header the the Superformance one. Anyone have opinion on the quality. Price is pretty good.

If I get the new header I plan on using exhaust wrap to keep the heat down. Any opinions re ceramic coating vs wrap.

Thanks

Barry

 

It's a 2V. I will have the head ready to remove this weekend so I don't know what kind of problems I'll run into. Based on what I've read the solvents don't seem to do much good but they can't hurt. Another forum (Alpha) recommend Acetone and ATF so if I have trouble (likely) I'll try PB Blaster and maybe Acetone/ATF. and a dead blow mallet. If that doesn't work I'll seriously consider the "rope" method per Mike's thread. I'm aware of the potential problem of moving the sleeves and opening up a whole new barrel of snakes. I suppose the rope method could bend a rod but I doubt it as there isn't much angularity that close to TDC. I wouldn't use the starter in any case, just a long breaker bar.

Still wondering about the quality, fit and longevity of Superformance headers. I'm not going to put the rear header back on with the heat shield in any case, can't stand the way they look and they rattle like crazy no matter what I do. It sounds like it takes a cut off wheel and snips to remove the heat shields. I hate to do that as I'm trying to save all the original parts for future restoration if desired.

Quick question. Are the original headers Stainless Steel?

The head gasket is still an open question but it sounds like the MLS type have potential compression issues due to the cylinder sleeves protruding above block which in turn could cause compression issues which as I take it could cause water leaks. I've never had any head gasket issues with the original (I think) gaskets so maybe I'll just get the standard ones from Superformance. I does make me wonder, though, why shops like Carid sell the MLS type.

I will decide how far to go with a valve job based on intake valve leakage and if a quick lap doesn't seal the new exhaust valves.


Barry

 

Doing it with engine in car so I'm not going to mess with front head. Compression and leak down were great, no smoke out exhaust and virtually no blow by. Passed CA smog with flying colors. Will replace exhaust valves and seals on rear bank as all four old ones are bent. (don't ask) I doubt seats or pistons are damaged as I did this myself while torquing cam pulley bolt. I will check guides but I think they are OK. Will also check liner protrusion and block and head flatness. Only reason I'm doing this to adjust valves and change cam seals due to small leak. After reading all the threads I can find my main concern is the replacement head gasket. I prefer MLS but am concerned about sleeve protrusion and block and head surface smoothness.

Barry

 

Derek
I'm in California, a ways from you, however I may take you up on the valves and seals. I need 4 2V exhaust valves and seals. Are the valves OEM spec for 2V engine? Since the engine is still in the car I can't really hook up a pulley system or hang it from the rafters to pull the head off. I'll find out this weekend just how stuck it is. Who knows it may pull right off.(yeah right). As your in the UK do you have any experience with the Superformance headers and their standard replacement head gasket not the Elring one.

Thanks

Barry

 

Derek
A little out of sequence here. I read the thread on the Elring gaskets and water sealing seemed to depend on liner protrusion same with the MLS type. Is Henry Chin on this site?
I know it sounds cheap but $500.00 sounds expensive for a head gasket (unless I read the Superformance web site wrong). The cylinder pressure in the US spec engine with 8 to 1 compress (or something close) can't be high enough to cause combustion sealing problems. It sounds like most of the head gasket problems experienced have to do with water leakage again probably attributable to block / head surface finish or liner protrusion in the case of MLS gaskets or warped head or block which will probably leak no matter what kind of gasket. The engine has never been overheated so I doubt the head or block is warped but I will check.

Barry

 

Derek

Thanks for the help. I'll know more after I get the head off. Hopefully its just replacing the exhaust valves and seals. I will take a look at your blog.

Barry

 

Bent all four valves because as I was torquing the cam pulley bolt the belt jumped a tooth. Had the cams locked with paper under the cam caps. I felt it but thought it was just rotating, it wasn't. So I did it again. Then later clicked it over with the starter as a final valve lash check which bent the valves (I had been using the starter to rotate the engine to set the lash for several days prior to this so I didn't bother to check the cam timing again, after all, all I did was tighten a bolt). I was checking the valves in the front head and when I got the the rear there was excessive lash on all four exhaust valves. I checked and sure enough the exhaust cam was out of time. I timed it again and had zero compression. As I said dumb. It surprises me that the belt jumped a tooth (at least twice) but that's what happened. Really stupid on my part but I live with what I've got.

Yeah I figured there is no way to get the heat shield off without trashing it. I'm considering getting a replacement Superformance rear header and wrapping it with exhaust wrap as I would like to keep the original for future restoration is desired.

Barry

 

I had already plugged two of the air sample tubes because they broke off on there own. Apparently the PO had removed some kind of bracket that holds them. (the front ones are fine) so in any case I will remove the remaining two . The air injection manifold gave me no problems once I moved the header away from the head although the header nuts were a bit of a pain. Even though the header is free of the head and disconnected from the muffler and u-tube I cannot get it out. The heat shield hits the rear firewall (for lack of a better term) and I can't get it back far enough to clear the head. I removed the e-brake assy but still no luck. Since I'm pulling the head anyway I'll just remove it then.

Barry

 

The belt actually jumped 3 teeth. Since I didn't realize it was jumping a tooth each time but I stopped each time I felt it move (thought whole engine was rotating). There is definitely no compression on the rear bank cylinders and more than 60 thou clearance on the rear exhaust valves. It just never occurred to me that the belt would jump a tooth. What apparently happened was that I didn't have the exhaust cam locked tight enough and it moved one tooth each time. I'll know better next time. What actually bent the valves was using the starter to do a final lash check before putting the cam covers back on.
I'm wondering if it cracked the timing belt pulley which might in turn cause the pulley to jump a tooth. I was torqued the bolt to 80ft lbs. I've probably built a couple of hundred drag racing engines all the way to top fuel and never had anything like this happen. Not much I can do about it except give up (never) or fix it.
At least this gives me the chance to really clean and detail the diff and rear of engine as well as the back of the engine compartment.

Barry

 

Yeah your probably right. Just didn't want to get that far into it right now. I do like to drive it since I got it running again and don't mind (to much) the patina that comes with a unrestored 42 year old car. It's all original except the paint which is only 35 years old. I'm afraid if I rip it apart one thing will lead to another and I'll end up with a garage queen 5 years later. This was my daily driver for 10 or 12 years and we drove it everywhere. You would of thought it was a 4x4 off road jeep. Belly pan and front valance looks like they've been through a war and the paint has it's share of rock chips and a couple of creases low down where I hit boulders or something. Once in Yellowstone had a grisly bear stand up and rest his paws on the top (no damage). Long days and nights in parking lots cleaning filters and carbs due to bad gas in some out of way burg as well as changing points and such. Even spent some time in a bank parking lot (for the shade) tightening all the suspension bushings which shrunk to the point they clunked due to four 110 degree days in Arizona. Had to actually loosen the belly pan once or twice to get the gravel out. Kinda sounds like ROADKILL now that I think about it.

Until this happened I planned on a slow march through a long list of things to fix and cleanup. But nothing that would keep if off the road more than a week. That's kinda out the window now.

Barry