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-   Do It Yourself, Boating on a Budget (https://www.offshoreonly.com/forums/do-yourself-boating-budget-249/)
-   -   454 hp and torque (https://www.offshoreonly.com/forums/do-yourself-boating-budget/322018-454-hp-torque.html)

MILD THUNDER 01-14-2015 09:02 PM
So we have an 8:1 compression setup. What do we have for cam intake carb and exhaust ?

hammerdown500 01-14-2015 09:54 PM
Thunder like I said it's a 500 efi cam and induction setup.
Also running wet ss marine manifolds and tails

hammerdown500 01-14-2015 09:55 PM
But from what I am seeing. Looks like it would be a better blower motor with that low compression

Quick2500 01-14-2015 10:11 PM
Originally Posted by CDShack (Post 4249663)
The chart I have says a 781 casting is 118cc open chamber, so I looked online and one had it at 118cc, two had it at 113cc. All I've ever seen were big, at least 118.
I like the 049 castings as well. Probably the two best BBC big oval port heads GM produced.

I would say horsepower is in the 475 range (adjusted) and around 500tq give or take.
Your chart is wrong. I have 049 heads, all the chambers cc'ed out at 122 after a quick surface. I'm running 18cc domed slugs.

Quick2500 01-14-2015 10:16 PM
Originally Posted by hammerdown500 (Post 4249828)
But from what I am seeing. Looks like it would be a better blower motor with that low compression
How many hours on the bottom end and who assembled it and with what parts?

hammerdown500 01-15-2015 05:26 AM
It's a stock bottom refreshed with new rings.

apollard 01-15-2015 10:19 AM
Originally Posted by Quick2500 (Post 4249837)
Your chart is wrong. I have 049 heads, all the chambers cc'ed out at 122 after a quick surface. I'm running 18cc domed slugs.
Yep charts re-post the same data over and over. Very few are measured data, generally what was published by GM or some magazine. I had to cut my 781 heads to 118 and run 188 domes to get decent compression. Chambers vary badly also, I had one head that measured 4 cc different from chamber to chamber.

sutphen 30 01-15-2015 10:35 AM
Originally Posted by Quick2500 (Post 4249837)
Your chart is wrong. I have 049 heads, all the chambers cc'ed out at 122 after a quick surface. I'm running 18cc domed slugs.
is that w/ stock valves or aftermarket?

hammerdown500 01-15-2015 11:17 AM
Oversized 2.19 and 1.88 I think. Could be 2.25 and 1.88

Quick2500 01-15-2015 02:17 PM
Originally Posted by sutphen 30 (Post 4250060)
is that w/ stock valves or aftermarket?
Aftermarket. Even in stock trim, I've never seen a set of 049 or 781 heads cc below 121.


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