Cams not turning after cam cover install

Mabes101 · Post by **Mabes101** » 20 Oct 2018, 06:53

Hey all,

First time posting here. I've run into an issue that is a bit concerning during a head install on a 1995 850 Turbo. Long story short I had to replace my head because a few months back, I got too excited about some NA cams I had pulled from the yard and during the removal of my Turbo cams had them roll and crack the head in the car. So I went to the yard, grabbed a new head, and followed Robert DIY's and the Haynes manual for install. I got the cam cover on last week and noticed that the cam sprockets were virtually impossible to move in either direction. All my timing marks are lined up and can confirm the pistons are all in the right positions. I have now attached a new timing belt and my aux belt. Just tried to crank the engine over by hand to see if the timing marks were still in line after a few turns but was only able to turn the crankshaft to the point that the timing belt loads up with tension. No movement in the cams. I guess I'm wondering if anyone knows where I should start troubleshooting in order to get everything moving again. I know block isn't seized, problem definitely seems to be at the cams. Could my anaerobic sealant be keeping the cams from turning? or could my seals be lodged in the head weird.

Cheers,

Post by **erikv11** » 20 Oct 2018, 09:05

Welcome to MVS!

It' not the sealant or seals, those aren't strong enough to lock up the cams.

Are you certain the crank is on the mark? With the crank on the mark, I'd take off the timing belt and try each cam one at a time. Are they both jammed up, or just one of them? You should be able to rotate the cams freely with the crank on the mark.

It sounds like the cam cover has to come off again, but I'm curious where cams and crank are relative to the marks. Did you use the cam slots, are you sure you didn't switch the intake and exhaust cams? They are labeled you can check.

Mabes101 · Post by **Mabes101** » 20 Oct 2018, 17:40

Thanks erikv11

I wasn't able to move the cams with the belt off. Cam cover is off again, and I am now doubting what I thought was the timing mark on the crank. I thought I had seen a barely visible tick taken out of the end of the valley between two teeth, but now I feel like my eyes are playing tricks. Using the mark I think I see cylinder 1 is just shy of TDC, which I thought was right. I can confirm the cam marks are correct based on the factory marks that were on the cam sprockets and my own marks which i made prior to taking the cover off in the first place. I am going to try and use a liberal (but not ridiculous amount) of assembly grease on the journals when I put the cams in again. Maybe they weren't lubed up enough when I put the cover on last time?

I thought I was seeing something similar to this https://i.ytimg.com/vi/orDjbXKq24U/maxresdefault.jpg

Mabes101 · Post by **Mabes101** » 27 Oct 2018, 05:31

So here is where my head is at right now. This is my fault due to the mix match of parts I have been combo'd to make what I thought would be a working head. Here is where the parts have come from to the best of my knowledge and some numbers. If there is anyone on here who may know if the parts won't work or know what I should do please let me know. I'm about ready to start over with all cams lifters and head from the same car (I realize was the best thing to do in the first place). I've tried measuring parts of the original head and parts against the one I am trying to put in and with the exception of the lifter height in the car I can't see many other differences. Strange thing was that the lifters from the 1995 850 sat lower in the head than the lifters the head came with (Both hydro) which is not what I was expecting. I thought maybe the lifters from the 850 were putting too much pressure on the cams, though it seems the original would have put more?

Lifters - 1995 Volvo 850 Turbo (Head they came from has 3340 - 1.2 on cam cover and 1001664 P01)
Head - Came from what I remember was a NA late model 850 or early s70 (Wasn't the RN)
Cam cover - Late model 850 or early s70 (Not RN) Numbers 3340 - 3.1 and 1001671 P02
Cams from 1995 Volvo 850 Turbo

Thanks

Post by **precopster** » 27 Oct 2018, 06:00

Did you mismatch cam cover from another head? This would be my first suspect. They were machined to match.

Mabes101 · Post by **Mabes101** » 27 Oct 2018, 06:12

Thanks precopster,

Yeah, I seem to remember I did. I had pulled the cover with no issues on one car and while pulling the head off the same car I had a cam roll on me and crack a journal on the left side. The cover from the car I found the head I am trying to put in was already gone. I should add that I've tried putting the cover on, bolted down to just past finger tight and still couldn't turn the cams. I may just have to bite the bullet today and get a complete head and all the parts from the same car. Bummer but I'm really running out of ideas, and if you're saying that they are machined to mate basically only with each other then it may be time. Lesson learned.

I've also been reading that I should only pull from a turbo 850 due to sodium filled exhaust valves. Is there and other reason I should not use an NA head?

Post by **precopster** » 27 Oct 2018, 06:24

Did you lube the cams with assembly lube?

I'm not saying unmatched head and cam cover will absolutely cause cam lock up but other instances of this on other threads have ended badly for that reason.

Mabes101 · Post by **Mabes101** » 27 Oct 2018, 06:26

I lubed the journals in the head and cover. Do I need to be lubing the lobes of the cams as well?

Post by **precopster** » 27 Oct 2018, 06:34

I don't think the lobes would have enough friction to stop the cam from turning however I have never put a head together without pouring a liberal amount of oil or assembly lube on both the journals and lobes, especially if they have been sitting for some time.

Are you trying to turn the engine at the 36mm nut on the crank with a decent length of bar or by trying to turn the cams at the head?

Mabes101 · Post by **Mabes101** » 27 Oct 2018, 06:46

I've tried both and get no movement at all. Without the belt on, the crank turns just fine but when it's attached to the cams I get nothing. I had a 10mm socket on the bolts that attach the cam cog to the shaft, and put a good sized strap wrench on the cams cog to try and turn and get nothing. I definitely don't have and dry contact points whether it be oiled or lubed.

As I mentioned I thought the issue may have been lifter clearance, but now that doesn't even make sense seeing as the 850 hydraulic lifters sit just lower than the lifters that cam in the head.