Warped Cam Cover?

BeachWagon · Post by **BeachWagon** » 22 Apr 2019, 11:53

I've been scouring the site as well as the web in general a bit and could not find any information in regard to my issue.

So I'm nearing the end of a head gasket job on my 96 850R wagon. The head was warped beyond what I was comfortable with having repaired, so I opted for a known good replacement head instead. The donor was a 95 850 turbo. It was fine. I had the bottom mating surface shaved a few thousandths for a fresh surface, installed new valve stem seals, hand lapped the valves, and installed with a new gasket. No big deal, it went together great. NEw head studs torqued down rather nicely to spec and in sequence with the two step torque and 130 degree spin on an angle gauge. Then came time to install the cams and cover. I used anaerobic sealant, and installed the cams, oiled all the cam bearing journals and then installed the cover with the drawdown tool. Torqued all of those little 10mm bolts in correct sequence to 12 ft lbs.

Now comes the problem and it's driving me nuts. My cams are VERY stiff, especially the exhaust cam.... to the point that i have trouble rotating just the cam with a large prybar. Out of curiosity, I installed all new timing components and tried to spin it at the crank by hand. Exhaust cam was so stiff, the timing belt was trying to jump teeth with the tensioner load. Not right at all.

Is it possible that my cam cover is also warped? For the record, yes I am using the original cam cover. It did not have this problem before i tore down the top end. In fact, the engine ran rather smoothly. My thought is that if both the head and cam cover were warped in the same manner, the cams would still turn normally. Now that I have a flat/true head, installing a warped cam cover might give me this issue right? Is it possible to even have the cover warp without just breaking? If so, how far and wide are my options for a donor car? Would the cover from a 98 S70 be sufficient?

Thanks in advance.

Post by **June** » 22 Apr 2019, 12:09

I believe you have to have the cover to the head you used. June

BeachWagon · Post by **BeachWagon** » 22 Apr 2019, 12:14

I sure hope not, that one is now long gone with the car it was in.

Post by **erikv11** » 22 Apr 2019, 13:06

It is posted all over the forums that the P80 cam cover is matched to the head, and they should not be mixed. That said, people have also posted up about mixing them just fine, and I don't recall if I've seen a post where mixing them was a problem. Doesn't mean it will work for you, but it gives hope.

I doubt that installing a (slightly) warped cam cover would do this, as the cover is soft aluminum and will bend to match the head even if torqued down in sequence. One main point of the sequence is to draw the cams straight down, otherwise they may crack the slots in the head.

My first guess is that the cams are in fact not installed correctly, apologies for wasting your time if they are but ... were the timing belt sprockets ever removed, or left on the cams? Are you sure you didn't switch I and E cams while the sprockets were off? Did you use the slots in the back of the cams for timing when they were installed? Was the crank on the mark (not at TDC, but on the mark) when you installed the cams? I can only think of these obvious things as possibilities.

BeachWagon · Post by **BeachWagon** » 22 Apr 2019, 13:15

Sprockets were left on the cams, which were marked with "E" and "I" on the face. Crank is indeed right on the mark, and is locked in place with the crank locking tool. Cams were lined up with the cam locking tool on the back end, and the timing marks with the shroud on the front end.

It's a damn shame that I can't get the cam cover that came with this head!!! Maybe I'll luck out and another cover will do the trick.

Post by **RickHaleParker** » 22 Apr 2019, 14:38

Did you use a Cam Cover Press to remove and install the Cam Cover?
What is the Volvo part number stamped on the Cam Cover?

Post by **precopster** » 22 Apr 2019, 19:13

Which surface did you machine? The upper surface of the head or lower surface of the cam cover?

Either way the clearances for the cams are shot. You should NEVER have them machined. Two thousandths and it will squeeze the cams too tightly. The new head you fitted should have been supplied with its own cam cover.

Only use this matching one or risk a matching/clearance issue , even if NOT machined, just Volvo at its finest throwing you a curve ball...

BeachWagon · Post by **BeachWagon** » 22 Apr 2019, 19:53

The lower surface of the head that goes against the engine block was machined. Neither the cam cover nor the top part of the cylinder head were touched. Unfortunately the cam cover that came on the replacement head was left behind and is now crusher food. Just gotta figure out what i have to do in order to keep moving with the head i have.

Post by **precopster** » 22 Apr 2019, 20:15

If assembly grease is used and cams/crank are in correct position you may need to replace head with a matching cover or keep trying cam covers until one fits. Sorry to break the bad news....... I wish there were a quick fix.

A machinist may be able to measure upper and lower cam journals and work out how to match them but this would involve removal of the head so you can bring it to a machinist and possible machining of the cams by machining as well.

We recently had a guy here on MVS with the same conundrum. He had to get another head with the original cover.....

Post by **abscate** » 22 Apr 2019, 20:18

Get a new complete head , skim it, move forward. Learning experience, move on.