Main Bearing help

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If the mains are stock specs, and the rods are stock specs, you could run the std volume pump but i'd run the HP spring pkg. If the rods check out at .0025 - .003 than I dont care what clearance the mains have, the std duty pump will have a hard time keeping the pressure up. I dont typicall run wide clearances. I set them at .002-.0025 MAX. I also modify the passages so there is no starvation issues. The grooves supply oil to the rods 100% of the time as opposed to 50 or 75% like 1/2 or 3/4 grooved. So if the rods are stock spec at .0008-.0015 ish, you will be fine. If they are wiedr than that, you will see lower max pressure. How much lower... hard to guess. If you run the HV pump, buy the MP oil pump drive from mancini. As was said.. the pinned gear and hardened tapered shaft. The SP one is NOT what you want.
 
I wont run anything but full groove on a small block. If you are going to run any kind of substained high rpm I would strongly recomend it
 
ok so I plastigauged the main and it came out to .002in maybe a little smaller using the green plastigauge. How does this sound?
 
havent checked those yet, should I do that with the crank out or what?
 
If you are using plastigage, then you ned the crank in the block... but it would be easier to not have the pistons installed. If the pistons are installed, make sure you have them numbered on the bottom flat on top of the pin bore with which side is front, (you will have 4 rights and 4 lefts per side) and what cylinder number you put them in so they can go right back there. .002 on mains is perfect. But, the rods will be what causes the mains to be starved if they are too big. Like TheCrusher, I don't use full grooves unless its real high rpm engine. 3/4 is more than fine, and I always modify the feeds to get more oil to them.
 
well this is what they said to get for my block becasue its a 76 so that Why I got them
 
74Burntorange said:
well this is what they said to get for my block becasue its a 76 so that Why I got them
Click to expand...


1/2 groove Magnum/later LA engine:
http://store.summitracing.com/partdetail.asp?part=FEM-4999MA10&autoview=sku

3/4 groove Magnum/later LA engine:
http://store.summitracing.com/partdetail.asp?part=FEM-5095MA&autoview=sku

Off Summit's site, and I verified thru the Federal Mogul online catalog. I never call Summit without knowing the part number i want...lol. It cuts down on the return good authorizations and UPS pickups.
 
also, the pistons are installed on the rods. There is no way to just put the rod on the crank, tighten it and then take it off and check? While everyhting is off the motor?
 
Just put the pistons in the block without rings to check the rod bearing clearances. Matter of fact, not a bad idea to oil all the bearings up and put all the pistons in there and see how it spins.
 
I know what you have... I'm telling you there were other options the guy on the phone missed. Better options for your intended use. If your pistons are pressed pin and mounted, no biggie. As was said, stick them in correctly marking them, with no rings installed, and check the clearances on the rods.
 
Ok I checked the number 1 cylinder and it looks like it came out to .0015
on the fattest part becasue the little piece slid back a little when i turned the stand to tighten the bolts. But I guess this is good?

ps there was also a piece that came off and stuck to the cap which meausred .002 but looked like it dident really get squezed good so
I believe .0015 is what its at
 
I monkeyed around with the plastigauge when I was putting mine together. Then I decided to buy some dial calipers from summut and a dial bore gauge off ebay and measure them that way. Its much easier and much more accurate because you can check the crank and rod journals for run out and taper with the caliper.

I also paid the local shop to check all that out too. I just wanted to double check.
 
The shop that did my crank and the shop I was going to have do my work said the crank was fine.
 
I would check all the clearances, run out, and end play anyway just to be sure.
 
all the clearances should be good if both places said it was good...
 
Not necessarily,everyones interpretation of good is different.If one guy thinks that the housing bores are good on the tight side and another one thinks that the crank is good on the fat side,throw in a bearing that may be on the fat side and you end up with almost no clearance.
 
some are making it seem as If I should go with the HV oil pump? or maybe just fo with the stock one with a HP spring to keep presure up becasue its IDEL pressure Im looking for at least 20pounds at idel
 
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