Printable View
Hey guys I have a 468 BBC in my airboat and was wanting to see if yall could help me out with a horsepower/torque estimate. I don't know all the specs but what I do know is that it is pretty much stock except for a mild cam and RPM performer intake to go along with 830 Holley carb. Thanks.
i did a air boat l think it was 15feet long with a 526 big block chevy you need to give me more on the 468 build to nail down hp and qt if that all you have 400hp??more less hard to say
What do you need to know about it exactly?Quote:
Originally Posted by pat mccarthy
well the more the better what heads you have or casting numbers any work done to them big valves bowl work .how much CR you have cam numbersQuote:
Originally Posted by justinduke
Here is what my brother sent me about it:
Camshaft pn erson cam e120201 grind no rv15h
Duration as advertised 288 at in and exhaust
Duration at .050 214 at in and exhaust
Gross Lift .492 at in and exhaust
Lobe Center 112
1250-4250 Rpm Range
60 over TRW Flat Top Forged Pistons
96cc chamber heads off of 427 67-69 model camero, chevelle and corvette.
Should be about 9.5:1 cr
Edelbrock performer intake
Holley 830 cfm marine carb
This is about all I know about it. The casting numbers for the heads are 3931063.
I'd say pretty close to 400HP, maybe a little less. But you could definately use a little bigger cam and benefit from it. The flow of the heads, if they are stock... will support around 5000 rpms on a 468, so when looking for a new cam look for something in that range.
in a air boat you do not want a big cam you can not go much past 4500 rpm ..this would have to do with what gear box you are running if you over run the prop bad things will happen ...hi 300 hp
Thanks for the help guys. I don't have to worry about over spinning the prop because it has a 2.68:1 gear reduction. What would you guys suggest to get this motor up closer to 550-600hp?
Do you really need more? What are the power/speed requirements of the prop?
Kitz
Quote:
Originally Posted by justinduke
If what you have is stock, a whole lot more. Im usre Pat and Erik will give lots of suggestions.
Well I would at a minimum like to have 500hp at least. Pitched almost like I want it the motor is only turning 4k and I would like to be at 5k with the same pitch or maybe some more pitch. It's pushing a 18x8 airboat so it's a lot of weight.
the one i did is about 480hp but i think what you want is QT more then any thing so the bigger the better on cid i would do a 496 or 511 one would used a 4 1/4 crank that would be a 496 and the other is a 4 3/8 crank i have done both the 496 is easier to find a shelf piston for it.
We just rebuilt this motor so it's gonna stay a 468 for awhile at least.
same prop as the one i did is has on it??
a new cam some thing with a lsa of 108 or less and carb i think is to big
OK. You do need more power and if you know what you have now you can estimate what you need at 5000 rpm. The boat weight does not matter. The only thing that matters is how fast you want to spin the prop and its torque requirement at that speed.Quote:
Originally Posted by justinduke
Kitz
Any other suggestions on what I should do for some more power?
swap out the cam run a hyd roller custom grind on a lsa of 108 or less to make max tq and hp before 5000 .some head work or a set of alum heads edlebrocks is what i used .it would help with weight to.try to get one more point of cr with the cam on a 108 a 4-7 swap cam you may see 5 hp there and use the air gap intake
What kind of gain do you think just the alum. heads would make?
how much was done to them?? the cam is were you will see the most for$$ i think. hard to say about your heads. i really do not think you need HP but QTQuote:
Originally Posted by justinduke