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I've tried 2 diffrent cams and both take alot of force to turn, one was even the original for this head, the head was rebuilt and had been media blasted, does it need to wear in or is this a serious problom ? This is happening with nothing else installed just the cam
Are you sure you have all the cam caps on the right spots and torqued properly?
Yes and checked my other heads and Cams spin much easier in them, the cam journals in the one with issures are dull from the blasting I'm thinking they may be damaged from that but I'm not sure if they just need to wear in or it's ruined?
Assuming you do not have followers in head. If not, you probably have a warped head. My rule of thumb is the camshaft should turn using only fingers on lobes to turn camshaft when torqued to spec. (obviously without followers in place). If you need to install sprocket on end of camshaft to turn it by hand, the head or camshaft is warped/bent.Try loosening the cam caps. If the head is warped it will typically be the center #3 cap that makes the camshaft bind up. Since they do not use locating pins, you could just try loosening and re-tightening to see of camshaft turns better. BTW better make sure the oil galley plugs were removed and a brush run through oil galley especially if the head has been media blasted, otherwise you will never get all that media material out. Failure to remove all that crap can result in lots of other collateral damage. Turbo, main and rod bearings damage etc.
BTW make sure they are in correct sequence too.
Todd
Yea no followers, with 2 and 4 loose it's easier but still needs hand on gear to turn (about how my others are fully torqued in the proper sequince) would it be possible to Polish the journal with 1000- 1500 to on the head to get a little more clearance.?
What did you torque the caps to? They should be no more than hand snugged, really. Actual spec is like 17 ft-lbs, or 120 in-lbs.
Yeah at this point you might want to run some 1000-2000 grit paper to clean them up a bit. Whomever did the media blasting should have known better than to not protect those journals. Did the guides ID get blasted too? Certainly isn't going to hurt anything to try to clean them up a bit. I've used a large socket that was almost the same size and wrapped sandpaper around that to clean up burrs caused from media/debris getting trapped in journal before. That worked okay.
I know, finding cylinder heads that aren't all screwed up is getting tougher all the time. Does the machined surface that the cam journal caps mate to cylinder head look okay? Many times guys that beadblast cylinder heads have the caps off and they drag the cylinder head across the cabinets steel grated floor and gouge up the mating surface. Seen that dozens of times before.
Well good thing your checking and addressing the issue. Many would say screw it and run it, or never even know to check it (lol).
Todd
It's really disappointing finding stuff like this , they did not remove the oil galley plugs, I did and was debris even though it should have been cleaned by them, and now this cam issue. really better off with used parts since it seems none if the local shops can do things right, I'm trying to get it rotating like it should but even after cleaning up all the journals the cam is practically seized when installed and cant be turned by hand on gear. so not even worth trying to run it like this...
Cap bolts where tightened to 14 ft lbs using correct pattern
Your head might be warped, and if that's the case, no cam is going to work. I would try cleaning up all the journals first and if you still have issues with the cams turning (check with no rockers on, then you will need to have the head checked. If it's warped, you will need to have the caps cut and the journal align bored, if you can even find a shop that can do it. Might have to start with a another head.
Good Luckl!
There are a few "red-neck" ways you can fix this.
1) In the past I had a friend who lost the caps for his head. He was really in a bind to get the car on the road so what we did was install one cap at a time with no followers and rotated the cam checking for tight spots. If there was we take that cap and with a fine sandpaper roll and a die grinder and hone it till it spun free. Then move on to the next one till they were all done. Crude I know but the car was on the road over a decade after.
2) The V8 guys will sometimes get minor core shift and when the cam bearings are installed and get some binding. They will shave the bearings by taking an old camshaft that has a "V" cut out of the bearing surfaces and rotate it a few times. The "V" will shave off the high spots in the bearings.
Otherwise you will have to take the head to a machinest to have it "line bored" to true everything up.
Some good advice in this thread so far, but I didn't see where you mentioned whether the head is bolted and torqued to a block while you are checking cam rotation. when checking cam/head journal brg clearance always torque the head to the engine with the head gskt. you will be using. It makes a difference.
The technique of using an old cam core to make a brg. surface shaver tool (Like Gary mentioned) is not at all "red-neck" I've used this method more that a few times over the years and it is damn effective when done right.
I take an old cam core, A 3inch cut-off wheel in a die grinder and on every journal I cut a diagonal slot across the journal surface about 1/8inch deep. then in front of the leading edge of the diagonal slot I grind a shallow relief across the journal. Clean and lube everything up, drop said cam tool into head, install caps torqued to spec. and turn tool a few rotations till it turns free...VIOLA!! Remove tool, clean/dress journals with 2000grit paper and super fine Scotch brite and clean up.
Do this with the head bolted to block.
The most important part is making the cutting edge of the diagonal slots sharp.
if you have a machinist's flat edge or can borrow one, check the head for flatness across the rear valve cover rail, where the cover seals. Of course check the deck as well. When a shop decks a warped head it gets flat on the deck mating surface but if its 'twisted' it will show up in the journals and rail.
i think this will make the difference, i was checking with out the head torqued to the block, also i have an old tbi cam i can make this tool with and give it a try its still binding after torqued down. if i did find a good shop how much should i expect to pay for it to be line bored ?Quote:
Originally Posted by Warren Stramer
You are probably going to find very few shops that have the proper equipment to linebore/hone OHC cylinder heads. Most machine shops just don't have equipment small enough to do the job correctly. I have only found one shop in the MPLS, MN metro area (3.5 million people) that have the equipment & desire to do this work on our cylinder heads. I was quoted $200-250 to straighten, alignbore and hone and resurface deck of block. I actually thought (and so did owner of another machine shop) that this was quite reasonable. The owner of this cylinder head apparently thought it was not cost effective to spend that to salvage an otherwise good head, so repair was not done.Quote:
Originally Posted by Fox
Back in the day (when these engines were everywhere) they had a repair kit to bore, cut tangs, & install bearings to bring the cylinder head camshaft journals back to standard bore. The bearings looked exactly like little rod bearings. I have one cylinder head with this repair done to it. It works great as cam spins better than ever with this mod. This couldn't have been a cheap repair either.
Todd
thats exactly what i thought, just not worth repairing, ill try the diy methods if it doesnt work i just move on and build up a bare one i have or find a junkyard one that is still trueQuote:
Originally Posted by 4 l-bodies
I did almost this exact thing, working fine for me.Quote:
Originally Posted by mopar-tech