californiamilleghia said:WOW , with all the junk running thru the oil , how are the main bearings etc ?
The part to be concerned about is the piston skirts. Bearings in theory see filtered oil, the pistons get stuff splashed around. And the pistons are soft enough that steel/iron fuzz can embed.
Whenever we had a cam go flat during breakin we would have to replace the pistons. After two cams in a row went flat on breakin we made a policy of roller cams ONLY.
Noddaz said:Wow, that is impressive. And not in a good way.
Cam time! This will be fun.
Go for a 3/4 race cam!
Scott
Actually, the "K" cam is quite nice. I wonder if they still make it?
Pete. (l33t FS) said:californiamilleghia said:WOW , with all the junk running thru the oil , how are the main bearings etc ?
The part to be concerned about is the piston skirts. Bearings in theory see filtered oil, the pistons get stuff splashed around. And the pistons are soft enough that steel/iron fuzz can embed.
Whenever we had a cam go flat during breakin we would have to replace the pistons. After two cams in a row went flat on breakin we made a policy of roller cams ONLY.
Ok , I understand but it look a long time for it to grind down those lifters , and the filter could have filled up and gone to bypass mode...
I would pull the pan and check the rod bearings since you need to inspect the pistons anyway .
PS , most of the motors I have built are air cooled VWs that did not have an oil filter....
Several things to ad here. Unfortunately at least one is too late....Volvo offered a lifter removal tool that you have duplicated here. If they would not pull out gently I would not force them up for fear of damaging their bores in the block. You must always replace the cam in this situation, so I would push any stuck lifters down into the oil pan after removing the camshaft. We usually just left them there
. Never had any repercussions from that, and at least one B30 I worked on we saw for another 60K miles after leaving at least 7 in the sump.
Pete. (l33t FS) said:californiamilleghia said:WOW , with all the junk running thru the oil , how are the main bearings etc ?
The part to be concerned about is the piston skirts. Bearings in theory see filtered oil, the pistons get stuff splashed around. And the pistons are soft enough that steel/iron fuzz can embed.
Whenever we had a cam go flat during breakin we would have to replace the pistons. After two cams in a row went flat on breakin we made a policy of roller cams ONLY.
Roller cams in a B20?
In reply to VolvoHeretic :
No, Pontiac engines. But pistons is pistons and cam/lifter slag is cam/lifter slag.
In reply to Pete. (l33t FS) :
Ok, thanks. I was hoping I could get me some roller cams. 
I happened to stumble across a new-in-box D grind cam in my stash. So, really no excuse not to go that way.
The pan has been dropped and all debris cleaned out. Reciprocating assembly seems to rotate freely. Cam bearings looked excellent.
My lifter removal tool only required a few light taps with the slide hammer to remove the lifters. The lifters didn't really seem mushroomed on the bottom, just worn thoroughly.
New cam is in as of last night, and new thrust plate and fibre timing gear. The only parts I didn't have were the stupid water pump seals, which should be arriving today. With any luck it'll be all reassembled by this weekend.
Time for that hot isky cam I sold you last fall!
I love that these topics are currently juxtaposed on the "Latest Topics" list:
Pete. (l33t FS) said:californiamilleghia said:WOW , with all the junk running thru the oil , how are the main bearings etc ?
The part to be concerned about is the piston skirts. Bearings in theory see filtered oil, the pistons get stuff splashed around. And the pistons are soft enough that steel/iron fuzz can embed.
Whenever we had a cam go flat during breakin we would have to replace the pistons. After two cams in a row went flat on breakin we made a policy of roller cams ONLY.
You only see this on cam in block motors? I have *never* replaced pistons on an ohc engine when we have had valve/lifter/cam failures.
In reply to Paul_VR6 (Forum Supporter) :
I would bet that Pete's experience is related to the location of the cam above the piston skirts in the V8 engine. The contaminated oil drops directly onto the skirts. I never saw any issues with the Volvos where the oil drains from the lifter gallery well the the side of the bores. Similarly on the other inline engines I have seen with wiped camshafts, Triumphs and MGs. Those were never just camshaft replacements though, as they were always disassembled for bottom end failures.
In reply to TurnerX19 :
I never thought of it that way, interesting.
The other factor is that this was when cams failed during breakin, so they went from new to failed in a very short period of time.
I know other people just change the cam, lifters, and oil/oil filter and resend it.
With the pan off, unless this was a fairly low mileage engine I would have def replaced the main, rod bearings and thrusts......
MiniDave said:With the pan off, unless this was a fairly low mileage engine I would have def replaced the main, rod bearings and thrusts......
It's a Volvo, not something British. The rotating parts are more than sturdy.
Breaking in the cam proper.
Noddaz said:Wow, that is impressive. And not in a good way.
Cam time! This will be fun.
Go for a 3/4 race cam!
Scott
Well, he started the thread with 7/8 cam...
I think it's funny how we view someone's misfortune as a chance to spend their money to make it better.
Have had it out twice so far, about 40 minutes of driving. Oil pressure is good, and no untoward noises or smokes.
In reply to volvoclearinghouse :
New cam make it faster?
In reply to Stampie :
I was doing some research to figure out what the stock cam was in the engine. It's a B20F out of a 1975 245, so a bit of a bastard engine. The B20E was the high compression variant, and the stock cam on that was the 'D' grind, but I can't find definitively if that cam carried over to the low-squeeze F engine.
Regardless, the new cam has non-ground-down lobes, and my butt-dyno tells me its definitely smoother and pulls better in all the gears.
Last night I pulled the valve cover and checked the valve lash. it was a relief to find them all within spec (0.016-0.018") still, with the exception of one that inexplicably got about a thou' _tighter_. I relashed that one valve and will do an oil change pretty soon to drain out that cam-break-in oil.
In reply to volvoclearinghouse :
There was never much difference in the reciprocating assembly on a B20, at least for performance. The 74 75s had metric rods and an 8 bolt crank. Piston height sure looked the same no matter what engine, and they are all flat tops.
Cam and cylinder head is where the hot stuff lays. The E head had nicer ports and a smaller combustion chamber, but valves were all the same size, I think. Possibly smaller on the carbed heads, but I don't think so.
So, how did the valve seats look? No valve seat recession?
Is recession an issue on Volvos?
Pete. (l33t FS) said:Is recession an issue on Volvos?
You betcha, but a 75 head has hard seats.
You'll need to log in to post.
