Align hone necessary? Tq plate?
 

Hey Guys,

I'm calling around and doing a bit of research on machine shops. I'm wondering whether I need to have my block align honed? And whether boring/honing with a torque plate is necessary? Some shops are saying yes, some saying no, some saying no real difference given my pretty modest objectives with the motor. So what do you guys think?

Thanks
Dan

(for reference, im shooting for 350hp NA with this. no blowers or bottle, nothing extreme, probably won't see more than high 5k rpm range, etc...)

Dan M No being a machinist by trade, only a mechanic, and having built a couple of motors, to do it right and have a squared up motor, the cylinder should get matched to the pistons and the boring and honing should be done with the tork plate. I would ask George A at Gessford mashine or Kieth Craft on his talk forum, they are the top of the chain on building motors. Rick Lake

Dan had a chance to play with a sbc a few years back with a torque plate could pull it out of round about .002 on a 400" with out being prepared with a torque plate but not in the case of a 350" more meat around the studs I guess, also the temperature of the block had a lot to do with it. Now as far as Align hone goes if you can tear down the motor and look at the bearings and they all look the same for ware my feelings is don't fix what isn't broke.

The bottom line is some there are machinist and there GOOD machinst just like drivers some know what to do with there equipment and some don't:)
Ken

If the crank turns freely when installed then align honing is a relatively expensive additional procedure that will make no discernable difference.

On the other hand, if you are getting the bores rebored anyway, and you have the choice of with or without torque plates at much the same price then I would choose the latter.

Just my two pen'th

Myles

Align honing the crank bore is only need if the bore is out of round or off center due to abuse of the block. Easy check is to set the crank torque the caps in place with out the rear seal and give it a spin. It should spin freely with no drag in any spots. I just use two fingers and give it a push. If it goes around a time or two and never stops in the same place it is more than likely ok. You can also turn it very slowly by hand and feel for a spot that hangs or sticks. If you find one hone it! You need to do this after the crank has been redone and checked for straightness. Just send in the crank to have it redone and hang on the block till you get it back.
It is a good idea to use plates when you finish hone the block. They will pull the block to the same shape as it will be with the heads bolted on. If your machinist is worth his salt he will ask you for a set of the same head gaskets you are going to use on the engine for the plates. So you will need two sets of head gaskets to do it the "Right" way. Also if you are going to stud it you should have the studs installed you are going to use for the engine again for the same reason.
If you are building a mild street engine don't waste your money. The small amount of change you will never see and you can use the extra money on something else that you will see a difference in like better tires or brakes.
My two cents.

Thanks guys.

Well the quotes I got from most shops were about as follows:

Just the overbore + hone: ~100$
Bore/Hone w/ tq plate: ~100$ more
Aling hone the mains: ~100$

So I'm looking at $100 more for each. Not grossly expensive, and I'm not trying to cheap out ... but as you said, that 200$ could go elsewhere if it would be better used there......

I'm going to be using the stock crank, but it needs to be turned probably 10 under. So maybe I should just take the block in and have it cleaned for now, and have the crank work done, order up my new main bearings, slap it together, and see if it spins freely? Then decide if I need the align hone, and take the block in for the rest of the work after that?

With respect to the torque plate ... again, most of you seem to be saying it's not necessary?? I would like decent reliability from this engine, but at the same time, it's intended to be streetable, and won't be subjected to anything hugely extreme.

Thanks
Dan

use the torque plate money else where.
auto10x
Bill