Am I missing something???

**tinbender71** · 05-04-2012, 04:50 PM

Ok here is what I started with: 18 Wriedt Stinger fairly heavy boat.
455 olds, mild cam, logs with thru hull 700 Dbl Pump.
Berkeley JC with "A" impeller and jetovator.

With this combo I turned 4900 rpm, and managed to squeeze 60 mph.

I put together a BBC 454 with a Doug Herbert HERCLB3N 275/285 advertised, .500/.530 lift, 112c
stock flat top pistons, 8.5-1
049 heads Air Gap intake, and logs, same 700 dbl pump

With this combo I turned 5000 rpm, and got 60 mph!!

I put on a set of headers today, hoping to gain a little, didnt change a thing.

Is this all its going to do? I have a 750 vac holley I can try. Anything else Im missing?

**wolfie** · 05-04-2012, 04:55 PM

You may need to step up a little bigger with the carb. Try the 750 to see if you get more but you may need an 850.

**blender over** · 05-04-2012, 05:06 PM

U need to match your impeller to your hp curve-rpm.
Tons of threads on here about it.

**fourtznme** · 05-04-2012, 05:22 PM

With 8.5 to 1 compression ratio, I don’t think you’re going to get to much more than what you had before.

**rogerroost** · 05-04-2012, 05:45 PM

5000 with an a seems reasonable to me. what are you hoping for? sounds like your olds motor worked good.

**tinbender71** · 05-04-2012, 06:20 PM

Thanks guys, these were the kind of responses I was expecting. The Olds did run good, but it was getting tired. I got a great deal on a junk boat with a nice but stock 454. And for some reason just had my heart set on a BBC.

I guess I was expecting maybe a few hundred rpm maybe, especially after putting the headers on. BTW, its not near as loud as I thought it would be with headers! I also have a set of the aluminum OT pipes, and the headers are much better sounding, and I swear a little quieter!!

Dont get me wrong, the 454 runs great, much more responsive than the Olds, runs smoother, and just a lot more fun to drive. I am not expecting to race it, just thought it would do a little better with the Chevy.

**rogerroost** · 05-04-2012, 06:24 PM

have you looked at a impeller chart

**tinbender71** · 05-04-2012, 06:31 PM

Yes I did, I did a lot of searching before I ordered the cam and intake. I thought I picked parts close to what a lot of guys have had success with. LOL, I am online right now looking at pistons!!

**Cas** · 05-05-2012, 12:34 AM

Originally Posted by tinbender71

Ok here is what I started with: 18 Wriedt Stinger fairly heavy boat.

Anything else Im missing?

you said it yourself, fairly heavy boat. More power and rpm may not do all that much speed wise until unless you can get more boat out of the water, more rpm doesn't necessarily mean more speed.

**jetboatperformance** · 05-05-2012, 07:57 AM

Originally Posted by tinbender71

Ok here is what I started with: 18 Wriedt Stinger fairly heavy boat.
455 olds, mild cam, logs with thru hull 700 Dbl Pump.
Berkeley JC with "A" impeller and jetovator.

With this combo I turned 4900 rpm, and managed to squeeze 60 mph.

I put together a BBC 454 with a Doug Herbert HERCLB3N 275/285 advertised, .500/.530 lift, 112c
stock flat top pistons, 8.5-1
049 heads Air Gap intake, and logs, same 700 dbl pump

With this combo I turned 5000 rpm, and got 60 mph!!

I put on a set of headers today, hoping to gain a little, didnt change a thing.

Is this all its going to do? I have a 750 vac holley I can try. Anything else Im missing?

Tin..Your numbers are about right for engine and Impeller, it could use more Carb for sure , Cant recall but does this boat have a bow tank ? suggest take every bit of uneccesary weight (if you havenet already) out of the boat and if it has a subfloor check for trapped water under it and go run it again Tom

**BrotherWolf** · 05-05-2012, 08:38 AM

Originally Posted by fourtznme

With 8.5 to 1 compression ratio, I don’t think you’re going to get to much more than what you had before.

Ditto!

**tinbender71** · 06-10-2012, 04:48 AM

Wanted to bring this back to let others know of what I found. I put an 18 gal tank in the back of the boat, and lost the 27 gal!!!!!! monstrosity that was in the bow. The difference was amazing! Boat rides better, takes off better, AND I gained 8 mph!!! Im hitting 68 now with now other changes! Hell, it even felt better towing on the trailer!

**Last Mohican** · 06-10-2012, 06:00 AM

Originally Posted by tinbender71

Wanted to bring this back to let others know of what I found. I put an 18 gal tank in the back of the boat, and lost the 27 gal!!!!!! monstrosity that was in the bow. The difference was amazing! Boat rides better, takes off better, AND I gained 8 mph!!! Im hitting 68 now with now other changes! Hell, it even felt better towing on the trailer!

Wow. That is a big gain. Congrats on getting it sorted out. What lake do you boat on?

**1975sleekcraft** · 06-10-2012, 06:25 AM

Originally Posted by tinbender71

Wanted to bring this back to let others know of what I found. I put an 18 gal tank in the back of the boat, and lost the 27 gal!!!!!! monstrosity that was in the bow. The difference was amazing! Boat rides better, takes off better, AND I gained 8 mph!!! Im hitting 68 now with now other changes! Hell, it even felt better towing on the trailer!

what RPM'S are you hitting now?????

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Am I missing something???

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