Auto vs. Marine - SBC Vortec

[Beech2000]

What are the main differances between Auto aluminum intakes and Marine.

I am having trouble keeping the budget under control building a 5.7 liter removed from truck and entertaining the idea of using non emision aftermarket intake auto type. Any concerns?

Note boat usage is used in fresh water only.

[Frosty]

The difference is auto is better and cheaper -- exellent idea and the way to go.

I have done this myself to a chevy block mercruiser, An Edelbrock dual plane for 4 wheel drive torque. The best money I ever spent.

[Beech2000]

Originally Posted by jack frost

The difference is auto is better and cheaper -- exellent idea and the way to go.

I have done this myself to a chevy block mercruiser, An Edelbrock dual plane for 4 wheel drive torque. The best money I ever spent.

Thanks. That's exactly what I wanted to hear. What do they cost and whats the best place to purchase?

[Frosty]

No Idea how much they are today. This was in Uk years ago. Absalutely no idea where to get one in the states.

Stone breaker will no doubt be along shortly and tell you exactly what you need to get.

[jimslade]

Marine aluminum intakes are bronze lined, automotive is not. As long as you Never run in salt water you should be fine. Aluminum will not last as long as cast. Just make sure that you use a marine cam and engine gaskets.

[Frosty]

To be honest I just cant imagine any one running raw water cooling systems these days.

[Beech2000]

Jimslade,

Bronze lined. Yeah, I do remember running across a marine intake lined with bronze but remember it being almost 800 USD on some website. Ouch!
I can buy 4 auto manifolds for that price. A new one every two years and still would be ahead. I do know about the gasket needing to be stainless. Received camshaft education from stone in another thread.

Jack frost,
Are you speaking of closed cooling? I had this system in a fourwinds 170 with 470 engine. What a mess the engine was but liked the antifreeze coolant. I just don't think I need it with freshwater lakes around here though.

thanks for the help. Will look for the edlebrock performer.

[Frosty]

Yeah well if your only using it in fresh water and taking it home with you, it'le be fine.

[stonebreaker]

www.summitracing.com

[stonebreaker]

Marine cams

For some reason, they list the p/n 109811 and 109831 cams as marine cams, but they didn't list the 109821 cam, which is probably the best cam of the three. It's right between the other two in terms of duration, and all the other numbers are the same.

[Beech2000]

Hey Stone,

You mentioned in a differant post that you liked the Ramjet cam from GM.
Is the 109821 similure.

I found out I can actually go for a little more radical of a cam than I thought. This late information was shared to me by a very good machine shop who took the time to call Crane with my boat information. i.e. length, engine size, prop size, and primary function of boat.

I don't think the 109821 was mentioned in my notes.

He did say the choices for roller marine were more limited than the previous generation SBC's.

[stonebreaker]

What did Crane recommend?

The ramjet cam is a good choice, and you can see its power curve on the ramjet, which has the same iron vortec heads as your engine, in the GMPP catalog: http://www.gmperformanceparts.com/_r...talog_2006.pdf on page 39.

ramjet cam: 196/206 dur at .050, 109 deg LSA 350 hp at 5200 rpm
Crane 109821: 214/222 dur, 112 LSA 400 hp at 5800 rpm
Crane 109831: 222/230 dur, 112 LSA unsure of hp with vortec iron heads

The 109821 cam gave my car about 50 more hp and 50 more ft/lbs of torque on similar heads, but somewhat less torque below 2000 rpm. It moved the horsepower peak upwards about 600 rpm, to 5800 rpm, although the torque peak stayed the same at 3500 rpm.

[Beech2000]

My appologies Stone,

I spoke to Comp Cams.
They recomended the following

Comp Cams PN 08-416-8
Link to specs.

This cam seemed more radical then the RamJet Cam.

[stonebreaker]

Not really. It's very similar to the Crane 109821, just a little less exhaust duration. It looks like it will work just fine.

[Beech2000]

Just need the torque to be strong from 2000 to 5000.

Stone,

Is there a place to store pictures on the net.

The freind that gave me the engine wants to see its progress.