I have some spare parts laying around and was thinking they might make a good engine

Re: I have some spare parts laying around and was thinking they might make a good eng

With an actual deck @ 10.188" those would be .048"(with your 6.600" SSM rods) in the hole and if you use the new sbb 350 Flat Out Gaskets that are .050" thick those would be .098" in the hole. For a boosted engine those would be a good choice because the compression ratio can be adjusted to where you want it by how much is milled off the deck.:TU:


Derek

 

Re: I have some spare parts laying around and was thinking they might make a good eng

I've seen a few 6.8" bbc rods out there with sbc big and small ends. I just bought some unused alum's for a Pontiac stroker (2.200" .927"), and a similar piston to yours.
Actually quite a few lengths near that.
Would this help?
I would do that over heavy decking.
If rod ratio is any concern, once you are real long the % of piston speed change is less. (yes, I know what happens going 2-1)
My apologies in advance, as I've only skimmed this thread...

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Very good points! I think that there may be some good options for e-bay rods, I will keep an eye out.

My current plan is to measure the actual deck of the block after it is squared off, then spec a custom piston for the SSM 6.600 rods because they do not need any work to them for the Buick 350 bearing or crank. I am pricing out a few brands of forged custom pistons.

For sure something to keep in mind!

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Hey Sean

Replies are slowing down. Need some action here.

So which engine is waiting for the new aluminum heads?

Paul

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Hi Paul,

My good engine is almost ready to button up and that one has the Hershe rods, diamond pistons, 8.9:1, turbo cam, very well ported iron heads with oversized valves... Internally balanced with sfi balancer and flexplate, topped with the alum X factor intake, and CSU carb... Will use the turbos on this one till the next engine is ready.

The next build will get the ta heads and intake, mpfi, megasquirt, custom pistons that i need to order once i measure the deck height and once ta tells me the head cc, full block girdle, those super strong 6.600 rods, also internally balanced, roller cam and twin turbos. Not sure if i want to set it up for E-85 or not, but it would open up the option to build it at 11:1 compression for either boosted with E-85 or NA with race gas. This will be more of a max effort build vs. the other one...

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Hey Sean, do you recall how much heavy metal it took to internal balance that 350?


Derek

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Sean

Do you mind sharing the specs on the turbo cam.
Looks like it's going to be a lot of fun!

We never ran over 10:1 static compression ratio on our methanol turbo engines. The 430 SBF and the 522 Hemi GM
On the mpfi setup you could run a dual fuel setup with 2 injectors per port.
One for pump gas when under 0 boost and the other for racing fuel for boost or track.

Paul

 

Re: I have some spare parts laying around and was thinking they might make a good eng

I will be getting my heads and intake sent straight to Chris Skaling for porting, then they will be ready to bolt on....

Hi Derek, they did not need to add any weight the the crank just drilled some holes to remove weight from it. I have the spec sheet somewhere... I do remember the rods were about 100 grams lighter than stock and the pistons about 150 grams lighter than stock. I remember the guy at the machine shop said he was really happy with the balance job and with the nice rods and pistons I was using it should be safe to rev to 8000 if the oiling was up to the task. I plan to shift at 6000 but still good to know.

I was going through boxes of parts today and i have 6 sets of pistons i will not use, might as well sell em and use the $ towards ordering some customs...

I asked Venolia, diamond, and scott brown for a quote for pistons based on my rough specs so we will see how that goes. I am considering waiting till i have the ta heads in hand and then designing a custom
Piston top shape complete with valve reliefs and then have the piston maker replicate my prototype... Any tips on that Paul? I have some extra stock pistons that i could use or some flat tops..

I am leaning towards a spherical dish and shooting for 9:1.

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Sean. If yor shooting for 9 to 1 I would use heads that still around 58 cc chambers . The dish in my piston is pretty large and we are just under 9. Pistons do look nice . Ross piston thru Scott Brown.

 

Re: I have some spare parts laying around and was thinking they might make a good eng

I am using 1.65 ta roller rockers but the cam specs are for stock rockers.*
*
Advertised cam specs
intake 284* .496
exhaust 276* .446
based on 1.55 rockers
*
Duration at .050*
intake 226*
exhaust 210*
*
Lobe lift
intake .320
exhaust .288
*
Lobe seperation 114*
*
at .050 tappet lift
Intake opens 3.0 BTDC
closes 43.0 ABDC
*
Exhaust opens 43.0 BBDC
Closes -13.0 BTDC
*
This is by Crower, and it is the same cam Jay had successfully in his turbo 350 Skylark.

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Get your cam first and degree it in according to spec.
Then fill the top of an old dish piston with clay and run it through with a new head on using light springs on the valves. (just 1 cylinder)
Then add .150 to the valve pocket depth and .100 to the pocket diameter. There needs to be .050" from the edge of the valve head to the sides of the piston pockets.
You could do something creative like temporarily gluing a .150" thick aluminum disc to the valve heads that is .100" bigger in diameter.
Then bake the clay
I've never used one but the piston manufacturers have a kit available that lets you do impressions that dry hard.

Paul

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Thanks, those pistons look good! Are you zero decking the pistons? Any idea the cc of the dish? One last question... What compression height?

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Good info! Would you have a spherical dish with the valve reliefs or would you try to have a raised area to help squish up into the head? Or just a flat top with valve reliefs but that would be too high in compression unless i let the pistons stay down in the hole which would reduce the valve reliefs to almost nothing if any were even needed... Not trying to take a short cut, just weighing options.

 

Re: I have some spare parts laying around and was thinking they might make a good eng

The last 2 low compression piston sets I ordered one from Diamond and the other from Autotech, I specified Spherical dish. In both cases I got a round dish with flat bottom but a generous radius from the outside squish area down to the floor. I was told that it was a better design.
You really do want the squish area not just to control detonation but to create some turbulence to aid combustion.
The one on the left is for a 430 and the right is for a 455. Diamond's 45 cc dish



I edited my last post. Valve to piston clearance should be at least .150" to give you some room to move the cam timing.

Paul

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Very nice Turbo cam!!
I really like Crower cams. We run a Crower in our blown alky engine.

Paul

 

Re: I have some spare parts laying around and was thinking they might make a good eng

I'm going by memory so may be a little off, I'll check later and edit if my memory fails me.

Piston diameter is 3.903" compression height 1.850" and I think 35cc dish. Since the gasket thickness is .050" the deck will be machined so pistons are .005" out of the hole to obtain a .045" quench ring.


Derek

 

Re: I have some spare parts laying around and was thinking they might make a good eng

My email from Scott list compression height as 1.840 and 35 cc dish. .827 pins

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Thanks guys for the info! Good idea about getting that piston up at just above zero deck... How did they know where you needed the valve reliefs? I know that when we had the custom diamonds made they had to be sent back to have the reliefs made a little larger...

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Derek gave them some measurements on valve placing since he has altered them slightly.

 

Re: I have some spare parts laying around and was thinking they might make a good eng

Funny.. I was reading that and thought "that looks like my cam" then I saw that it was..

I don't know why it works so well, but it does..

This is an email from the guy I sold it to..

That'sinteresting, I still can't get over the amount of traction I'm getting in theskylark with only me in it. I took a buddy of mine for a ride that dragraces and he refused to believe I didn't have some kind of crazy drag setup onthe rear suspension until he looked for himself. He agreed with my thatthe car feels well north of 500 horsepower and will run 11's all day long.