Engine Questions


Nov 14, 2011
Hi, the search seems to be down right now but I have a couple questions. I pulled my engine to check a few things. I was using a gasket scraper to remove the fiber head gasket residue and after I was done I noticed there are a few scratches in the aluminum heads from the scraper. There isn't a lot of them, and they aren't that deep but you can feel them with your finger nail slightly. Is this a problem and should I have the heads shaved? I'm hoping not as I'm fairly remote :( Second question is what is the allowable crankshaft endplay? And if it is out of spec - then what?
If the scratches go across the sealing ring area they might need to be resurfaced. That's one of those things that have to be inspected in person to give a qualified answer.
I think crank endplay should be around .005-.008. There are oversize thrust bearings available, but if the crank is that worn on the thrust surface, the crank needs to be machined for the oversize or replaced.
Ok, I don't think the scratches are over the sealing ring. They are very faint, would there be any harm in giving them a gentle sanding with a scotch brite pad or something? Also I checked the crank end play and it is .012".
I would want any surfacing done with the proper machines. I would have them checked by a good machine shop.
do not sand the scratches out with a scothbrite. if you have a leak you'd much rather have a skinny creek than a wide canal.

If you suspect they are going to cause problems just bit the bullet and have the heads resurfaced by someone that knows what they're doing.
Take it to the machine shop for a freshen up,you already have it out. That is cheap in the end.
A good procedure to do a simple clean-up on a head or block surface without a machine shop is to use a piece of bar stock and some fine metal finishing sandpaper.

I have a steel bar 1"x2" and about a foot long wrapped with the sanding cloth that is used especially when doing a head gasket job in the car to do a final cleaning on the block head surface.

Sounds like that may work in your situation. :)
Is .012 with new bearings or the old ones? New bearings may put you at .008.
The engine is 3 years old - with very vew miles. I wasn't planning on pulling the bottom end apart at all.
I probably have at least twice that in mine and It's been that way for 10 yrs now. I was running one of those vigilante converters, and that is what caused it. My machinist told me that since I wasn't running a standard trans, that it shouldn't be a problem. I have excellent oil pressure.
Are the scrapes easily seen by eye or only if you rub your finger over it. If Just by finger i wouldn't worry.
Well you can see them in the aluminum, and you can feel something on your finger nail. My plan is to do the oil pump housing plate glass sand paper trick. Stick some 400 grit on some glass and run the heads accross it, then go to 600 grit. Think it should work?
Well you can see them in the aluminum, and you can feel something on your finger nail. My plan is to do the oil pump housing plate glass sand paper trick. Stick some 400 grit on some glass and run the heads accross it, then go to 600 grit. Think it should work?

I would go 600 to 800. Or maybe even 800-1000. 400 does not seem fine enough.
It's going to be difficult to slide a head thats larger than the sandpaper on a sheet of glass. Nick's method works well if you can find a flat piece of bar stock.
If you're going to try and hand lap the entire head I wouldn't start off with anything finer than 100 grit. And you'll most likely still be there all month with 100. The first 5 seconds will show you any high spots or tell you if the head is warped, twisted, or tacoed.
Well I gave it a go yesterday. I set the heads upside down and put the 400 grit on a sheet of glass, wet it down and dragged it accross the head. It seemed too coarse so after a couple of passes I went to 600 grit. I cleaned and wet it down a couple of times and used 3 pieces of sand paper on each head and I was pretty happy with the results. You could see the contact all across the entire head surface and the fine scratches pretty much came out. I stopped when you couldn't feel them with the finger nail - just a very faint line. So I bolted them down. So while I'm on the subject - and my thread is vaguely named engine questions... So it's been a few years since I put the engine together last... So I've got .012" crank end thrust and .0035" camshaft end thrust. I ran a tap through the block head bolt threads and tried to rinse out the holes. I then wire brushed the ARP head studs, applied Loctite 567 and ran them in finger tight. I then cleaned the block and head surface with wax and grease remover. Of coarse put on the head gasket and dropped on the heads. I then applied moly lube to the nut threads and bottom where it contacts the washers and torqued the heads as per Champion's instructions. I put some engine assembly lube on the roller lifters and popped them in the holes. Did I miss anything or any tips going forward?
After you're happy with the head nuts being torqued down roll the engine over and blast as much of that moly out as you can. That stuff will coat the bottom of the pan for a long time. Moly isn't good to have floating around in your oil as it's larger than the orifices in the oil filter.