Well the step-son got a bug in him and he pulled it all apart! I got piles and bags of parts and a bare block.

Initial observations:
When the cam sprocket and timing chain broke the valves in a few cylinders look like they tapped the piston tops.

So I've got a few pistons with little dings in them.
Question number 1 then is do I go ahead and clean these up or could the tops be weakened enough I should just replace them?

Cam looks ok if I was building a street engine, couple of gouges and worn spots.
Question number 2 what cam to replace it with?
Remember goals are 350 rwhp/ 5000 rwtq (yea I know the torque number is impossible. I just want max torque with my rwhp restriction)
Heads and valves - I think its repairable, I'll probably be ahead of the game getting one of the sets of heads on the shelf fixed up instead.
Question number 3 using 1.6 RR, what springs, shims, keepers etc should I get? Remember this will live at 3K - 6K rpm almost the entire time its running.

I'm taking the block to the machine shop to be cleaned and checked. I'll figure out from there if I have to have any real work done.

And it begins - plan is to have it together by mid-March and in the car before Easter.

350hp on a 383? the CI alone should get you there.

Pistons? a lot will depend on if you have to hone or bore the block. You may end up with a 384!

What heads are on it? If stock, I would go AFR.

I don't know enough about cam selection.

I'm class limited on rwhp, but not torque
Any more than that I'm in the spend a ton of money to run mid-pack, two tons to run at the pointy end.

Yea, I'm holding off on the final piston decision until the block is checked.

Only problem with the AFR heads is the $$$$. I have two sets of heads on the shelf that just need cleaned up and new springs. I can live with leaving a little on the table.

As long as the piston is not cracked it's fine. Valves bending don't usually hurt pistons beyond a little eyebrow in the valve relief.

Springs and such depend on the cam.

350 RWHP it would be easy to detune it down to that with whatever cam you run. Worse come to worse just make up a restrictor plate to go behind the TB.....

I personally think the stock LT1 cam with 1.6 or 1.7 rockers on a 383 would be pretty close.
Will

With Will's suggestion, perhaps a stock LT4 cam with 1.6 rockers wouldn't be the perfect fit?

Do remember, the LT4 was putting out a rated 330hp; the real number is more accurately 350 to 360.

I guess the LT1 cam might be best.

Have your machinest mic. everything out n go from there.
The main thing is getting all tolerances in specs. for desired application, after machine work pre-assy to check #'s, make corrections, then if all cool final assy.
As far as damaged/worn parts, discard them , unless u r bandaiding things, jus mho
I am happy to help any time if u have questions.
714-879-9671/David.

Quote:

Thank you sir! Your suggestion on replacing parts that look damaged or worn is right where I was thinking. I just wasn't sure if the minor nicks in the top of the piston was too much or not. They can catch your fingernail, but not much deeper than that.

I've decided to go with an LT4 Hotcam since Summit Racing is right down the road, its in stock and I need assembly lube, bearings, gaskets, etc.

Another question - I probably should have the balance at least checked on the current crank. All the smooth places are nice and mirror finish so there does not appear to be any wear. OK, enough of that on to the question. Bob weight = piston, rod, pin, clips, rings, nuts, bolts - Correct? or am I missing something?

What machine shop are you using?

Quote:

No.

The Bob Weight = 100% Rotating weight + 50% Recipricating weight.

Rotating Weight = Big end of the Rod (w/Bolts) and Rod Brgs.

Recipricating Weight = Piston, Wrist Pin, Locks, Rings, small end of the Rod (and small oil allowance if you want).

You need a special fixture to properly weight the connecting rod and get your big and little end weights.

I have a MS Excel spread sheet that I built to calculate Bob Weights for the shop. Once you have all the weights is real simple to use. If you want a copy let me know.
Will

Yes please let me know how I can grab that spreadsheet from you.
Machine shop is just going to do the machining I tell them so I have to be perfect.

The block should just need cleaning and checked, Its a golen block. I do expect surprises, but I hope I have none.
Is the fixture to weigh the big end and small end something I can fab up or something I can find inexpensive - Right now it looks like I'll only use it a few times

Quote:

Not easily Jim.

This is one, Will and David probably have better ones. This one's $147 and you need a digital scale to use it.

http://www.summitracing.com/parts/PRO-66844/

Shoot, $147 to use this on 16 - 32 rods in the next few weeks. Wonder if anyone would loan me one?

I'm going to pick up a digital scale anyway cause I'll use that for other things.