hey guys what do you think about summit racing rebuild kits for an 1971 oldsmobile 350. the kit runs for like 600 dollars and it comes with forged aluminum pistons. sounds like a deal?

 

All depends on what you are going to do with the engine.
If you take it to a machine shop or not.
I am in the process of rebuilding mine and have spent well over 2000.
His kit price was around the same price as summits but. all the work they
do adds up.
plus be carfull what cam you pick with thoes pistons, they are flat top
and will take your comp. to around 10.1 to 10.5.

 

your 110% right mp71, well this motor is going to be just a little hotter than mild but still remains a daily driver, the block is going to the machine shop. the cam that is going to be mondello's hyd 22-25-10 with 110 centerline. what do you think, is 10.1 going to knock with 93 octane?

 

by the way that is one nice motor you have

 

Which pistons? Do you have a brand and part number?

Norm

 

I looked at their website and it does not specify (I bet what you did too, hence your question).

 

Nope. Without a part# it would be a waste of time.

Norm

 

True, it would be nice to know exactly what pistons were going in the engine. Forged aluminum is very non-specific.

 

http://store.summitracing.com/partde...1&autoview=sku

here you go guys, let me know how you feel about this kit

 

That is the one I looked at. It does not specify the part numbers of the pistons used. You might give their tech line a call as find out.

 

http://store.summitracing.com/partde...t=TRW-L2320F30

 

btw those are the pistons that come in the summit kit.

 

I am not sure the part number of the pistons, but when I got them they were the flat top. I thought that was good untill I did some reserch and found that the cam I picked had the intake valve closing at 35 degrees abdc.
That woul give me a dynamic cr of around 9.5 - 1. way to high to run on pump gas. So I had them machine a 6cc dish to give me 9.5 cr and a dynamic cr of 8.8, which is at the limit of 91 octane.
Sealed power does sell a piston with a 6cc dish, but you have to see all the specs on your cam.

 

If you're taking everything to the machine shop and having the crank ground, rods reconditioned etc., have you thought of going with aftermarket rods, (6.2 SBC) and a 400 piston? Parts are cheap and you end up gettnig better stuff for the same or less money. Just a thought.

Also, although I'd lie to see a bigger split between the intake and exhaust duration, the 22-25 cam should be fine but please don't limit yourself to Mondello/Engle grinds. There are alot of other good cams out there.

 

Not to be mean, but... please DON'T do this. There is NO reason to run aftermarket rods in an Oldsmobile engine that will be a daily driver or weekend warrior. The stock Oldsmobile rods are high quality and won't give you any trouble unless you plan on running 10 seconds or so in the quarter mile.

A Summit rebuild kit is just fine if you want a daily driver/weekend warrior.

 

True, but here is the option Mark was suggesting. For $500 you can get a new after market SBC rod and forged pistons. It will probably cost more to get forged Olds pistons, press off the old pistons and recondition 35 year old rods. Rod bearings and possibly rings will probably end up being cheaper, too. There is the additional cost to bore to 4.125" (which gets you a few more cubes and unshrouds the valve a little better) and grind .025 off the crank, but in the end you have a nice little combo. So, it is just another option, that's all, nothing radical.

 

Looks like you are working with a competent machine shop.

Norm

 

The best thing I learned (and i only have build three motors), Is to
let your machine shop know what you want and what you plan to
do with the car. A good one will work with you and they know alot more
than you do (its there job).
I haven't ran my 350 yet but I am very confident that it will be just what I
wanted it to be.

 

i find it hard to belive that you can get 6.2 rods, 4.125 forged psitons for about 500 dollars can you please tell me where and what site there at. thanks

 

Capt Jim hit the nail on the head, overall cost and quality of parts was what I was proposing. Maybe you can't get the rods and forged pistons for $500.00, but it wouldn't be much more than that. And when you factor in the cost of the rod recon, rod bolts etc that you won't have to pay for, in the end it becomes quite attractive.

I just did the same combo for a buddy, Turned out phenominal, really runs awesome. Something to think about.

 

I don't know that much about the 350's but before I built my 455 I did a cost comparrision on parts and ended up using cat rods, keith black pistons & edelbrock heads bought off of e-bay and it ended up costing only a few hundred dollars more the having C heads redone and rods redone and I am very happy with the results. In fact so much so that I am repeating the process on the 455 I am now building for my 48 Olds

 

www.flatlanderracing.com
2-ICR6200 6.200" Scat rod, bushed, 2.100" big end $279/set of 8
H-615CP Forged Speed Pro pistons, 4.125" P/H $29 each x 8 = $232
Total is $511, I lied

Deck height is 9.330" Subtract half of stock stroke is 1.692 = 7.638"
7.638" - 6.2" rod = 1.438"
1.438" - P/H of 1.425" = .013 in the hole. A .010 decking gives you darn near zero deck. Or, use a .028 gasket to get .041 piston to head.

 

As long as the dish did not thin the piston top by too much. I have heard 0.200 - 0.250 minimum thickness (depending upon the builder spoken to)

 

The number would depend on several factors. Most important, are the desired power level and the intended use.

Norm