[Skip Fix]

Starting to mock up mew block and crank specs before I take it to machine shop. Main bores all on the tight side 3.1880. When I add the Sealed Power 113M bearings I get a 0.004 clearance. Crank is 2.9995 on journals. Another brand a click tighter bearings? Or a 0.001 undersize?

Also main saddle oil holes not centered(except #1 last picture)-slot main saddle or notch bearing?

[AG]

I used the same bearings in my IAII block and opened up the bearing feed holes to allow a more direct flow into the bearing from the main saddle feed hole.

[Gary H]

Clevite or KIng bearings will tighten it up quite a bit compared to Sealed Power bearings. I'd open up the holes for the main bearing 1 through 3 too. I'd guess at least .0005 or a tad more tighter than the Sealed Power bearings based on what I see here daily.

[Dragncar]

Line up the oil hole in the block on the tab side, that is where the shot of oil comes from. I drill a whole new hole the same side as the one in the block. Clean it up with Dremmel and small file.

[Skip Fix]

I saw King also has 0.001 undersize so maybe get a set of STD and those to see where we get.

[steve25]

Yup, .004” is too much by .0015” in my book with a cast crank if that’s the case , but even if you where running a steel crank unless you where making over 750 hp and spinning the motor to over way 7200 I still would not want more clearance then .0035”.
Even .0035” is 50 wt oil territory!

It not just the misalignment of those oil holes that need to ground over, but if you look close at the way those oil feed passages are drilled out to form that feed channel in the block you will see that the area of the oil feed passage in the main web is bigger then the V shaped area the the oil flow has to pass through to get to the bearing hole and in some of the main webs to scoot over to the oil gallery on the other side of the block.

I always grind open these V shaped passages to match the area of the main oil feed passage.

[Steve C.]

opened up the bearing feed holes to allow a more direct flow into the bearing from the main saddle feed hole.

X2



.

[Steve C.]

Concerning the IA2 block.

From this:

http://www.allpontiac.com/online_cat...ding_notes.pdf

CHECK ALL OIL PASSAGES AND DEBURR IF NEEDED

EXAMPLE, take note that the location where the oil passages intersect within the front main can use some attention. The depth where they intersect is not the same as a factory block, it's closer to the bearing.
Similar situation on the three center mains.


.

[Skip Fix]

Forged crank-hoping for at least 750HP.

[Bill Eveland]

I had to line up all the oil holes on mine, i also dropped the intersecting area lower from the surface. Look at a factory block, they are over 1/4 down. I used a dremel and a tile grout bit that worked really good.

[Skip Fix]

Yep factory blocks they intersect and lower.

[77 TRASHCAN]

Skip, what’s this heathen 750 HP engine going in?

[Skip Fix]

Probably into the 79 Camaro/IA-but my projects take a year or two. Have a new trans for the Camaro to see if old TH400 is some of 60 ft issue. It has always felt just a little weird.

[mgarblik]

Many different approaches can be used to get the oil feeds in the right position for maximum flow. I prefer to modify the bearing shells vs the block. Some good builders groove the block and perform other modifications. The disadvantage of doing this is you are then married to a particular brand/style of bearing. On very high HP race engines, I open the oil feed in the bearing to expose as much area as the block can supply for the mains and rods. I do not worry or care about the cam bearing feeds. They get plenty of oil. Some pics for an IA II block with FM 113M bearings.

[Skip Fix]

Thanks.

Goal for the Camaro/IA has always been 10.00s in the 100 degree Texas heat-like last week! Hedging bets if the current motor does not get me there.

I know I saw an old RAV block years ago that had the cam bearing feeds tapped for restrictors. The IA seems smaller than main feed holes, compared to factory blocks. that seem almost the same size.