360 performance rebuild questions

Posted By: Moparbil

360 performance rebuild questions - 01/07/10 03:55 PM

Going to but put a 360 together.
Rotating parts are stock. Pistons are Keith Black 107 they are about 85 g lighter than the stock pistons. Has been told balancing is not necessary since they are out balancing each other.
Is that correct?

Piston rings are sold as file fit or non file fit.
What do I need for the KB107 ?
What is the difference ?
Will sealed power rings for 36$ do well, or shall I go for perfect circle for 100$ both are with moly. ?

Rocker arm kits are sold as 1.5 or 1.6 ratio
What to use ?

Thanks all

Posted By: hemi471

Re: 360 performance rebuild questions - 01/07/10 04:06 PM

I would re-balance! I would use file fit rings. And rocker ratio is 1.5 stock, Magnum 360 are 1.6

Posted By: mark7171

Re: 360 performance rebuild questions - 01/07/10 04:48 PM

If this is your first 360 keep it sijmple. Use factory magnum heads and valvetrain. File fit the speedpro rings on the 107's. good luck

Posted By: Rapid340

Re: 360 performance rebuild questions - 01/07/10 05:02 PM

Since KB hyperuetectics require a large top ring gap you should not need to buy file fit rings if you are going with a reasonable piston to wall clearance (.0015-.003).

Posted By: Moparbil

Re: 360 performance rebuild questions - 01/07/10 06:10 PM

Quote:

Going to but put a 360 together.
Rotating parts are stock. Pistons are Keith Black 107 they are about 85 g lighter than the stock pistons. Has been told balancing is not necessary since they are out balancing each other.
Is that correct?

Piston rings are sold as file fit or non file fit.
What do I need for the KB107 ?
What is the difference ?
Will sealed power rings for 36$ do well, or shall I go for perfect circle for 100$ both are with moly. ?

Rocker arm kits are sold as 1.5 or 1.6 ratio
What to use ?

Thanks all

well, file or non file fit I am confused. Do I understand it right ? Is file fit rings to be grinded to ring gab tolerance and non file have the correct tolerance out of the box. ?

Speedpro rings are mentioned is that the cheap ones ?

The dilemma also goes for the main and rod bearings, shall I buy standard or is the more expensive performance bearings needed.

Posted By: MoparforLife

Re: 360 performance rebuild questions - 01/07/10 06:12 PM

You will need to file gap the rings to get the proper top ring gap on the KB107 pistons. If you don't go by their specs expect to have trouble.
I for one have never balance my engine running them and it has never let me down. I know sever people running with KB pistons in both big and small blocks that haven't and have no problems or excessive vibrations and the engines have been very good longevity. None of us over twisting the engines and stick pretty close to 6000.

Posted By: Intense RT Dan

Re: 360 performance rebuild questions - 01/07/10 09:12 PM

That'll make it around a 9-10% overbalance but you'd rather have it overbalanced than underbalanced. Personally, I would shoot for 2% overbalance and be done with it. Overbalance is usually done to offset the inertial loads of the rod a piston as it starts to come back down the bore from TDC in a 7500 on up rpm engine.

Posted By: Moparbil

Re: 360 performance rebuild questions - 01/08/10 02:35 PM

Only the top ring on KB107 need a little extra gab, is not possible to file a non file fit ring to correct tolerance ?
At Summit file fit rings are nearly three times more expencive than non file fit.

Regarding rod bearings do I need to use performance bearings or just P series for this set up. Its going to used on street only.

Posted By: plumcrazy101

Re: 360 performance rebuild questions - 01/08/10 03:12 PM

Quote:

Only the top ring on KB107 need a little extra gab, is not possible to file a non file fit ring to correct tolerance ?
At Summit file fit rings are nearly three times more expencive than non file fit.

Really... A ring grinder doesn't care if you have file to fit rings or standard gap rings as it will grind them all.

Posted By: MoparforLife

Re: 360 performance rebuild questions - 01/08/10 03:31 PM

Quote:

Quote:

Only the top ring on KB107 need a little extra gab, is not possible to file a non file fit ring to correct tolerance ?
At Summit file fit rings are nearly three times more expencive than non file fit.

Really... A ring grinder doesn't care if you have file to fit rings or standard gap rings as it will grind them all.

I agree. Have built many of them and used ring grinder (much easier and more accurate than a file) an it could care less what kind of ring it grinds and will give you a correct ring gap. Always make sure to smooth the edges of the trim no matter what ring you use. I have seen many times where a regular fit ring needs to touched up a bit to get the correct gap.