22' scarab engine swap..

[jsm1]

Currently have a 1994 22' scarab. It has a 350 mag in it. Not positive, I think this same size boat came out with bbc in them also. I have a good deal on a 496 out of a camaro. It is built tough, all forged internals, h-beam rods, forged pistons, hyd. roller cam, dart aluminum heads. First question is whether the engine will work or not with it not being "marine." Next question is if it will work, where do I get the manifolds, and also what other parts would need to be changed. ...THANKS!

 

[Bt Doctur]

Re: 22' scarab engine swap..

brass core plugs or FWC system,
new /used Bravo setup,
relocate/fabricate new motor mounts
old starter and dist, alt will fit.may need some different brackets
BB wiring harness, manifolds, risers, Y pipe,
and I`m sure i forgot a few things too.

 

[jsm1]

Re: 22' scarab engine swap..

brass core plugs or FWC system,
new /used Bravo setup,
relocate/fabricate new motor mounts
old starter and dist, alt will fit.may need some different brackets
BB wiring harness, manifolds, risers, Y pipe,
and I`m sure i forgot a few things too.

Thanks for the info.. .Are you saying the engine will be fine in the boat? Even though is not a "marine" grade engine. I don't know what dictates the difference, but it would be nice to know.

Thanks again

 

[Bt Doctur]

Re: 22' scarab engine swap..

Marine Grade: the parts exposed to salt water are brass/bronze/SS,
charging, ignition, fuel systems explosion proof/protected
non emision cam, but not one with too much overlap. can cause water reversion in the exaust

 

[HT32BSX115]

Re: 22' scarab engine swap..

Thanks for the info.. .Are you saying the engine will be fine in the boat? Even though is not a "marine" grade engine. I don't know what dictates the difference, but it would be nice to know.

Thanks again

It is built tough, all forged internals, h-beam rods, forged pistons, hyd. roller cam, dart aluminum heads.

Well, the 800lb gorrilla in the closet will be the camshaft. That engine will have a cam that wants it to turn RPM's that make HP well over 5000 RPM.

You also will probably have a SEVERE reversion problem unless you put a "marine" cam in it. The wrong cam could probably "kill" it the first time out.....

 

[NHGuy]

Re: 22' scarab engine swap..

What he said is true. But also you need to research the cam. Marine cams are quite different, require either very little overlap or some loud pipes. Lumpy car cams can ingest water and they typically need higher RPM to develop their max power. A marine cam is closer to a truck or RV type to eliminate reversion and move the torque down to lower rpms. The early torque is necessary for take offs, it takes lots of oomph to get a boat onto plane.

oops HT has the quick response...

 

[jsm1]

Re: 22' scarab engine swap..

I will get the cam card out tomorrow. I know that the engine didn't turn real tight, I believe at around 5500 it was make 597 horse on 87 octane. It is a very docile engine. Good to know on the over lap though.

Another option I have: I have a p1sc pro charger laying around...I called up pro charger, they of course want to sell me a new one that is "marine" grade. Is there that much of a difference or would it work if I plumbed it up on the 350 mag.

My over all goal; is about 8-10 mph. By gps im hitting right at 62. My dad has a 24' baja with a 502 in it. He is hitting right at 69-70 mph. I don't know how much longer I can take following behind him.

Thanks!!!

 

[Failproof]

Re: 22' scarab engine swap..

Well if you want 8-10 more mph, polish, buff, slick coat the bottom, and pro charge it. And then run at 6,000 to 7,000 rpm. Carry a spare drive. What drive do you have now?

 

[Bondo]

Re: 22' scarab engine swap..

My over all goal; is about 8-10 mph. By gps im hitting right at 62.

Ayuh,... For those numbers, ya need a purpose built Marine BBC...

Figure 'bout $1,000.+ per mph...

 

[haulnazz15]

Re: 22' scarab engine swap..

What outdrive are you currently running? If the 350 Mag was mated to an Alpha drive, you won't be doing much of anything once a procharger or 496 gets strapped to it.

 

[jsm1]

Re: 22' scarab engine swap..

Yeah, I'm sure its an alpha one. I will verify to go from 99% to 100%. Even babying it out of the hole then getting on it? Will the p1sc pro charger work even though it is out of a car kit and not technically marine grade? Where would I get the manifolds to swap the bb in the boat.

 

[joewithaboat]

Re: 22' scarab engine swap..

This guy uses another forum i visit. He added the mph you are talking about by using a blow thru blower. He adapted an automotive head unit. Not sure about an a gen 1 alpha but i see loads of hopped up small blocks with gen 2 drives.

http://www.youtube.com/watch?v=aUhOJYhve7U&feature=email

 

[haulnazz15]

Re: 22' scarab engine swap..

Well, just keep in mind that the Alpha was max rated at 300HP. A blower is going to get 400HP+ most likely, so this isn't necessarily like a 310/320HP 350ci engine. You can start soft and stretch it out, but I would just not be surprised if the drive didn't last too long. That's the whole reason the Bravo drive was invented, because the 454's (with only 310HP) kept chewing the Alpha drives up. The torque from the 496 will definitely kill the Alpha, not to mention the differences in motor mounts/exhaust tubes/etc. It would likely be a several thousand-dollar ordeal to swap the 496 in, because you would be forced to swap the outdrive to a Bravo.

 

[joewithaboat]

Re: 22' scarab engine swap..

Well, just keep in mind that the Alpha was max rated at 300HP. A blower is going to get 400HP+ most likely, so this isn't necessarily like a 310/320HP 350ci engine. You can start soft and stretch it out, but I would just not be surprised if the drive didn't last too long. That's the whole reason the Bravo drive was invented, because the 454's (with only 310HP) kept chewing the Alpha drives up. The torque from the 496 will definitely kill the Alpha, not to mention the differences in motor mounts/exhaust tubes/etc. It would likely be a several thousand-dollar ordeal to swap the 496 in, because you would be forced to swap the outdrive to a Bravo.

I would never choose to run a big block on an alpha drive. However there are loads of people running 400+hp small blocks on alphas with no issues. Some are right here on this site.

 

[Flysfloatsor]

Re: 22' scarab engine swap..

A bbc was an option for that Scarab. A friend had one with a stock Bravo/454. Ran 68mph GPS. Then went 502 and it ran mid 80's all day. They can pretty much handle any reasonable power you can throw in. (with a bravo). First thing Id do is go bravo as soon as possible. Then toss that procharger on your SBC and a good set of trim tabs off the back, and run it like you stole it... Im talking ragged! All the while building a 502, for when your really ready to hurt some peoples feelings. Then if your not messing around anymore, put a short Imco or sport master lower, you might see 90.

Im in the alpha life support game for my last summer. Although, its worked very well for this boat for a LONG time! Likely because its under 2100lbs wet. The previous owner went 96 gps with the alpha SS.

 

[haulnazz15]

Re: 22' scarab engine swap..

I would never choose to run a big block on an alpha drive. However there are loads of people running 400+hp small blocks on alphas with no issues. Some are right here on this site.

I am well aware of it. I didn't say it wouldn't work, I only specified that the Alpha wasn't rated for it, and that he shouldn't be surprised if it failed in short order. I know there are a number of guys who are running high-HP SBC's on Alphas, but almost all of them are aware of the possibility that the drive life can be severely compromised, especially if run hard out of the hole. My point wasn't to say that he shouldn't/can't do it, it was to make him aware of the possibility of failure. Do you want to spend a few grand on a supercharger, then possibly another grand or two on a new Alpha after it shells itself. Or do you pay about the same amount up front for a used Bravo/transom plate and eliminate the issue altogether? Nothing wrong with either approach, just putting that out there.