I will find out what they did to mine exactly but it has definitely been along honed twice and everything is still good. Cam gear still has lash and cross bolts went in fine
Main Cap Walk
- Thread starter schulte
- Start date
Also again sorry lol
I have never run a billet cap and have never had main problems. I have reused the same bearings over for many years. I'm also poor and can't afford new stuff just because it sounds cool. I'm not a billet blinger like Wade.
I have never run a billet cap and have never had main problems. I have reused the same bearings over for many years. I'm also poor and can't afford new stuff just because it sounds cool. I'm not a billet blinger like Wade.
Geebus you guys are waaaaay over thinking this. Center line of the crank does NOT change when only the mating surfaces are skimmed, material will be removed from the ID of the cap to make the circle true again. Only time the centerline would be dropped is if the bore was too big, and needed reworked.
This is almost as bad as arguing with people about sighting in a gun with the one shot method LOL
This is almost as bad as arguing with people about sighting in a gun with the one shot method LOL
Caps
If you can cut a cap and not get into the block your a pretty bad dude. I think you would have chatter trying to cut one half of a surface.
If you can cut a cap and not get into the block your a pretty bad dude. I think you would have chatter trying to cut one half of a surface.
I won't speak for everyone Jeff, but when i say cut a cap I mean the flat part on a bridge port and then I go line bore it as part of the block where I have some meat.
It is very rare the cap is rounded and not the saddles in the block.
But it does happen on occasion and is a fairly easy fix.
If you manage to somehow in another universe cut one half and not the other, well you'll have one f$@ked up circle... Okay guys imagine instead of say .006 needs to be shaved off of each mating surface, it needs .5 inch from each side!!! That has to give y'all a better visual in your head on how the centerline will move up toward the cam (cause this ain't a free floating surface, the cap is pulled to the block via bolts)
Centerline
You can change the bore size and the centerline will not change. 1" or 3" and it's still the same centerline. If you cut the cap and resize the main the only way the centerline will not change is if you don't cut the block when resizing the hole.that would be a hard time cutting half a hole and keeping it strait and true.
You can change the bore size and the centerline will not change. 1" or 3" and it's still the same centerline. If you cut the cap and resize the main the only way the centerline will not change is if you don't cut the block when resizing the hole.that would be a hard time cutting half a hole and keeping it strait and true.
Caps
They also normally grind the caps and not cut them. I can see why some have troubles with bearings I guess.
They also normally grind the caps and not cut them. I can see why some have troubles with bearings I guess.
Thats exactly how it has to happen. the cap is curled and somehow the saddle in the block has survived, or at least it did not effect the part where the bearing rides. You cut the cap to get in the good meat. There is an art to it, and only the best machinist can get this done and have a perfect line bore and centerline. This guy Justin that I work with happens to be one of them.
Yes exactly. But both the cap and the block are messed up in this case so the block will be shaved thus changing cl relation to cam
That's right. And also, even if the bore was too big and needed to be reworked, you can still maintain the same center line, it would require a larger bearing though.
So many view, so many partial perceptions.....
IF you trim anything off the block or cap, you will shift the centerline of the new, now no-circular hole combination. True.
BUT the block side of the hole is still centered to the original location. Your local machinist can use it for reference to now cut the cap to keep the crank on the original centerline.
And no, it's not a big deal to line bore a block and only take material off the cap.
So everyone chill, the block is salvageable in the hands of a skilled machinist.
IF you trim anything off the block or cap, you will shift the centerline of the new, now no-circular hole combination. True.
BUT the block side of the hole is still centered to the original location. Your local machinist can use it for reference to now cut the cap to keep the crank on the original centerline.
And no, it's not a big deal to line bore a block and only take material off the cap.
So everyone chill, the block is salvageable in the hands of a skilled machinist.
An oversize bearing is the only way to do this. However main bearings come in undersize only for dmax, you would need to find a housing bore that is oversized in the apa guide and then spec a custom bearing. The next guy to work on it will hate you for this.
IF YOU CUT THE CAP MATING SURFACE ON BLOCK YOU WILL CHANGE THE CENTERLINE. THERE IS NO WAY AROUND IT IF YOU ARE GOING TO USE DURAMAX MAIN BEARINGS.
thanks for chiming in as I am especially concerned with the area of the bearing that potrudes. At that area the bearing could potientially be wider than the cap as it is torques down, once torqued down the circle will be perfect since it was align honed. However with the crank in place and only a few thou to wiggle with could the bearing be damaged on installation.
I think I understand that you are basically reboring a new hole in "good MEat" that will be lined up to the same centerline as the old hole. Ie the boring bit will just skim the upper most part of the bore.
The block side protrudes a small amount, but then again the cap side is slightly recessed. They match.
A good machinist can maintain the bore size provided the block bores are in alignment.
A good machinist can maintain the bore size provided the block bores are in alignment.
That is what I think we are all trying to understand.
How do you maintain the bore size in the recessed bearing area of cap. If you open it up maybe a thou or 2 so that the bearing backing plating material does not scrape on install, will this effect bearing crush?
And this is so hard to explain without pictures and I am sure that makes it a little harder. But I can picture in my mind exactly what you are describing.
Yeah but the block is f-Ed up too so you have to cut the block. Not just the cap. So that's not gonna work.