[AaronH]

All,

I'm working on a V-drive boat project and need help picking a cam. I need to build lots of torque. It's a 17'6" flat bottom, 350 with a powerglide. I bought the boat with a rod through the side of the motor. I want to reuse most of the parts from the broke motor in my build. Here is what I have planned so far:

350 .040 over
Stock stroke and rod length
flat tops, double eyebrow
between 10 and 10.5 to 1 depending on what head gasket I end up using.
1.5 aluminum roller rockers (I think, I still have to check them)
Edelbrock RPM heads 185 intake runners, 69cc chambers, 2.02's
Edelbrock RPM air gap intake
750 holley, mechanical secondaries
Rewarder dry headers

I called 5 different cam guys last week to get their recommendations. I was surprised at how some of them asked for very little information. They seemed to be all over the map a bit too. They recommended intake lift anywhere from .444 up to .547. I'm no cam expert, so I am a little hesitant to pick something because I don't want to make the the wrong choice.

I appreciate any input you guys have.

Thanks,
Aaron

[KMatch]

I believe anyone not asking for prop specs or gear reduction numbers isn't doing you any favors. I can't offer spec advice, but these play a big part in your quest - what RPMs this will be running, etc.

[AaronH]

I had the same thoughts. My guess is that for the average Joe Homeowner they figure that you aren't racing so they have a select group of cams they like to sell. Once they figure out about where you want to be at they drop you into one of their standard bins and don't necessarily match to the components you are trying to work with. Kinda like small, medium, large, etc.

As far as RPM's, thanks for the reminder. I forgot to include that. I don't plan on turning it any faster than 6K.

[seven up]

6K rpm ? That v-drive, or any v-drive for that matter, has to be in perfect alignment.

And you are using a powerglide ? Is that the automotive powerglide ?

Have you talked to Oregon Cam Grinders ?

[F-BIRD'88]

Isky Z-42

This one will make a ton of power.

See on the cam card where it says intake closes at 57° ABC

You want to degree this cam in slightly advanced so the intake closes at
53° ABC. Thats 5° advanced from cam card specs.
Don;t guess, degree it in accuratly.
This will build torque and help the boat get on plane fast.
Big big power from 3000 to 6000+

If your block is " o decked" the cr with 69cc heads will be 9.8:1
Just right.

You'll need to run 92 or better fuel in this motor.

[AaronH]

This powerglide has a torque converter eliminator kit. So, basically it's like having a full lockup converter all of the time. It's got a double cardan joint that connects it to the Casale box. Other than that, it's you average run of the mill short shaft.

I looked around Iskys site and I have to say it seems to be about the worst in terms of trying to find anything. I did call them and they spec'ed a lot more lift than anyone else. They were at .547/.555 (intake/exhaust). Closest anyone else came was .512. The guy gave me grind numbers S480 and S387. He also asked me the least about my build. He wanted to know engine, carb CFM, max rpm, and hp. I asked if he wanted head and intake specs and he said he didn't need it.

I want to make sure I get enough cam for my parts, but obviously I don't want to over cam it.

Thanks,
Aaron

[F-BIRD'88]

Originally Posted by AaronH

This powerglide has a torque converter eliminator kit. So, basically it's like having a full lockup converter all of the time. It's got a double cardan joint that connects it to the Casale box. Other than that, it's you average run of the mill short shaft.

I looked around Iskys site and I have to say it seems to be about the worst in terms of trying to find anything. I did call them and they spec'ed a lot more lift than anyone else. They were at .547/.555 (intake/exhaust). Closest anyone else came was .512. The guy gave me grind numbers S480 and S387. He also asked me the least about my build. He wanted to know engine, carb CFM, max rpm, and hp. I asked if he wanted head and intake specs and he said he didn't need it.

I want to make sure I get enough cam for my parts, but obviously I don't want to over cam it.

Thanks,




Aaron

The isky recomendation is very very close to what I said. The duration is essentually the same. I have used the specific Isky cam Isky recomended. It makes huge power. Mine was on a 106LSA. isky pn 201547
look it up.
Installed at 99 in C/L to max torque for a boat motor.
What was isky's custom LSA recomendation for this?

Isky knows their stuff. I just went a bit more conservative on the valve lift.
Isky lobes S385 and S565 on a 110LSA

Trust me you won;t come up short on cam with this baby in your boat motor. Can use a bit more compression. (you are limited by pump gas octane so...) Needs good Isky springs and good (scorpion) 1.5 rockers.

call Isky back and see if they want you to go with a custom LSA or if the 106 LSA of the #201547 is right for you.

These two cams are both proven cam for engines like yours. Like I said Isky knows their stuff. Work with them. They will nail it down.

What cam was in the last motor? Do you want more rpm? more what than before???

Your Edelbrock RPM heads are good. Naturally if you were to port and clean them up a bit they will work even better. You will make more power and go faster. Your heads are real good with some port work.

The RPM intake manifold ensures a stong torque curve and plenty of to end in this boat motor. A VIC JR makes just a bit more peak HP but gives up some torque.

If you don;t want to venture past 6K stick with the RPM intake for this.