I need some advice on an engine build. I just started and I am putting a brand new Eagle crank into an 88' 350 block. My problem is that the back part of the crank hits the block (I included pics). At this point I am unsure if the crank is the wrong one or if I should should relieve the block a little. Everyone else about the crank seems correct. The oil clearances are exact and the measurements are relatively close to the stock crank.

Also, does the crank need to be balanced before installing it? I just assumed that the factory balanced it and the harmonic blaancer took car of the rest.

I greatly appreciate everyones help!

 

The large counter weight on the crank would tend to indicate that it's
balanced for a heavy (stock) rotating assembly (rods/pistons).

You need to keep 0.060" between anything rotating in the motor, and the
block, so you will probably need to clearance the block a bit in that area.
(I've seen 383 cranks need clearancing in that area)

You should always have a new crank balanced, no matter what the
vendor says, every engine is different. A harmonic balancer is not a
"balancer", it's actually a damper.. It helps absorb vibrations that could
contribute to engine failure, it doesn't balance the crank. (Although ext
balanced motors store some of the balance mass on the damper for
convenience)

mike

 

I greatly apreciate your help! I am guessing that I am just going to buy a new crank, because as your said this one looks like it is for a heavy stcok engine. Could this be a truck crank?

Also, not to sound stupid but how would I go about getting a new crank balanaced. Also, how much HP can a cast Eagle crank support? Should I consider going with a stroker crank? Summit has one on sale right now for $175.00 for a cast, 1 piece crank.

 

There's nothing wrong with that crank, there's no reason to send it back. Just clearance the block a little with a die grinder and it will be fine.

It does need to be balanced though. You need to take it to a machine shop, with all your pistons, all your rods, a set of rings, and a set of rod bearings.

You could get a stroker crank if you wanted, but you'd need either new rods or new pistons. There'd also probably be more clearancing work required.

 

How will this crank do in regards to performance? I realize that I can make it work, but I rather it be a peformance enahancing part. Plus, I think the crank would still hit the side of the oil pan.

 

In regards to performance compared to what?

It will probably clear the oil pan fine, but even if it doesn't, a couple taps on the pan with a ball peen hammer will fix it.

 

In terms of performance I am looking to get about 350-400 HP. I just want to make sure that the crank I have or another similiar cast unit can 1) produce 350-400 HP and 2) Handle 350-400 HP.

Thank you for everyones help!

 

Even a stock crank will handle 350-400 HP without problems.