Cascade Crew

Quasi-Traction · Posted: Mon Apr 14, 2008 6:47 pm Post subject: 383 Kits and Questions.

Ok....

So with money to boot for my totaled truck, I think its time to put that 4 bolt main block I have into action.

Been talking to Paul and John about this, but thought I'd get some other input about this.

Here are the 4 kits I've been looking at.

http://store.summitracing.com/partdetail.asp?part=ESP%2DB13055E030&autoview=sku
http://store.summitracing.com/partdetail.asp?part=ESP%2DB13454E030&autoview=sku
http://store.summitracing.com/partdetail.asp?part=ESP%2DB13455E030&autoview=sku
http://store.summitracing.com/partdetail.asp?part=ESP%2D13054030&autoview=sku

Paul was suggesting either the 1st or 4th kit. I thought the 2nd kit was the best one.

Here's the cam I was looking at to go with it, along with an pair of Swirl Port heads off a 305.

http://store.summitracing.com/partdetail.asp?part=LUN%2D00010LK&autoview=sku

Crunching the numbers, here's what I'm accounting for: .041 head gasket, Pistons down .002 in the hole (I've heard a "Zero deck" aren't always 100% accurate and equal across both banks, so I"m giving a .002 tolerance from zero). Gives me a quench of .043 and a Dynamic Compression ratio of 8.27:1. seems to be a good number.

Also considering this cam:

http://store.summitracing.com/partdetail.asp?part=LUN%2D00016LK&autoview=sku

Same heads, same piston-to-deck clearence, same head gasket, I have a 8.48:1 Dynamic Compression ratio. I'm thinking for valve guide clearence issues, the second cam might be a better choice, plus being on a bigger LSA, there's less overlap and more potential for low end torque. Would there be any issue with the actual spring/seat pressures using this cam on a set of stock swirl ports?

Thoughts? Ideas? Fire away.

I want to try to squeeze as much power out of this thing now as I can. Hoping to be above 230hp and 270 ft/lbs with this combo at the wheels.

Al Hasse · Posted: Mon Apr 14, 2008 6:56 pm Post subject:

A friend gave me a CD from Motion Software you can use to help with crunching numbers. It's a 2003 edition, bit still worth a look. I'll try to remember and bring it on the 25th weekend.

Dewey316 · Posted: Mon Apr 14, 2008 6:56 pm Post subject:

You'll be fine with the 2nd cam for sure, the first cam havint .480 lift, might be close with the stock life of the heads, we would need to just measure what kind of lift we can get from the heads without machine work.

But, you can get other input, we can BS about this tomorrow.

---John

chevymad · Posted: Mon Apr 14, 2008 9:35 pm Post subject:

You either want flat tops with valve reliefs, or the D shaped dish. Either one will allow for valve clearance and still have a quench area. You dont want the large dish piston or completely flat top.

I've heard a couple machinists actually saying Scat is better then Eagle today too. Not sure how the price compares. If at all possible I'd try to swing some forged pistons. The cast crank I dont see as a problem though. But if you ever want to add any kind of power adder you'll want the forgings. Don't say you wont think about it either. Power is addicting, and your short block will be the limiting factor. Hypers are great N/A pistons but cast pistons work better then them in power adder situations.

Twilightoptics · Posted: Mon Apr 14, 2008 9:40 pm Post subject:

Chris. Use the kit I told you in the PM.

Forged slugs would be good if you could swing it. Hypers should be fine though as long as you don't boost it.

You want the Steel crank from the kit I told you.

Both 1 and 4 have Steel cranks. Stronger than cast Iron.

The first kit runs your compression a bit high. About 10.8:1. The 4th kit runs your compression about 9.6:1 with the 12cc dish. Much more managable. Best bang right there in the 4th kit.

You might do more research and find out for sure if the 4th kit isn't balanced.

I'd just straight stay away from the cast cranks if you're buying a whole rotating assembly.

Keep your piston CC's above 10 and you'll be fine for compression with 64 CC heads.

John... what are those 305 heads? 58cc?
We might have to enlarge the bore a bit.

Don't worry about cam, or squeezing power out. If you're using john's heads youre not going to be 'squeezing' power. It's just a get you by for now and have a good bottom end to start with.

Dewey316 · Posted: Mon Apr 14, 2008 9:43 pm Post subject:

There is some power to be squeezed. I saw some numbers from a flow bench, that showed the swirl-port heads actualy flow more on the exaust side, then the L98 heads do. I would guess with some clean up work on the intake side of things, so they can breath, they might do OK. The biggest limit is probably going to be the smaller valves.

Twilightoptics · Posted: Mon Apr 14, 2008 9:48 pm Post subject:

And the swirls.

Since it's not ideal I'd buy a super cheap like Summit cam just to get it rolling. Then when he does the heads he wants, then he can up the cam to the lift/duration he wants.

Quasi-Traction · Posted: Tue Apr 15, 2008 9:08 am Post subject:

Does anyone know who makes summit's in-house brand cams?

I'm a little hesitant to buy a vital valvetrain component like a cam from someone who isn't a reputable manufacturer. Stuff like the intake manifold, I would go with the summit brand for cost savings.

blue89 · Posted: Tue Apr 15, 2008 12:23 pm Post subject:

I don't know much about your setup, but isn't 230whp a little low to be asking? Even at 20% loss your only aiming for 276hp out of a 383? I'm pretty sure that the 383 could push 350ft/lbs so that would put your target 276 HP at 4141rpm.

Are you making more of a guess (based on your heads) than a "goal"? Forged rods and hyper pistons and you should be good for a little higher compression and much higher rpm. Plus you gain 4% per CR increased. But if you're head flow limited I understand.

i'm with Twighlight on the cam selection. Get something that matches your heads.

Twilightoptics · Posted: Tue Apr 15, 2008 1:30 pm Post subject:

blue89 · Posted: Tue Apr 15, 2008 1:45 pm Post subject:

No doubt that will be a strong bottom end! I'm all for working with what you got (that should be my motto).

chevymad · Posted: Tue Apr 15, 2008 4:32 pm Post subject:

Most people say the summit cams are made by Crane or one of their affiliates. They seem to match up to their grinds as well. I've not heard of anyone who has had trouble with one. They are just all old designs with slow profiles. So you leave power on the table using one with the same specs as say an xe or voodoo.

Quasi-Traction · Posted: Fri Apr 18, 2008 3:10 pm Post subject:

chevymad · Posted: Fri Apr 18, 2008 4:31 pm Post subject:

Problem with the comp rollers is that they're ground on a cast iron core instead of a steel core. It's more of a problem with solid rollers because of spring pressures, but even hydro's will wear tracks into a cast core cam. Comp will grind these on a steel core for extra money. The lunati's allready are on steel.

Quasi-Traction · Posted: Fri Apr 18, 2008 9:10 pm Post subject:

Hmm, intresting.

Thanks for the Head's up B.

I might still go with the Comp anyway. That cam isn't going to be in there forever. its just a "Get-me-by" cam. if I go roller, I'll replace it with a Mech Roller Voodoo when I do the heads.