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-   -   engine guys,,,build 468 won't run out (https://www.offshoreonly.com/forums/general-q/362572-engine-guys-build-468-wont-run-out.html)

daleroger 08-23-2019 09:06 AM

engine guys,,,build 468 won't run out
 
I built a 468, gen 4 with the following;
wiseco 9.5 forged pistons, crane 731 roller cam, full roller motor, dart alum heads, correct isky springs, 325 runners, 121 chambers, dui dist.single plane intake, holley 850 double pump,, rex aluminum exhaust manifolds. ,,,runs good, idles good, runs cool at 150 degrees, 60 psi oil pressure, 4,ooo rpm at 3/4 throttle, but no change applying full throttle. last year 21p prop turned 4700 with stock 454 mag.
Thought it was fuel pump, installed new holley electric, shows 7 psi.. At wot , fuel flow shows 23 gph,,,,,could the heads be too big for a 468 ?? yes the throttle is fully opened, ect. Same boat, same prop, 1988 265 Force. Would appreciate opinions from knowledgeable engine guys. Thanks,
Dale

F-2 Speedy 08-23-2019 09:16 AM

Whats the full advance on the timing and @ what rpm........I ran AFR 305's on 540's

14 apache 08-23-2019 12:28 PM

How's the mid range on the motor if you give it some throttle. Like 3k to 4k.

SB 08-23-2019 12:47 PM

Same prop ?
What is your fuel pressure at Wide Open and top rpm ?
Also, as asked, total timing ?

Baja Rooster 08-23-2019 12:58 PM

What size wire are you running to the DUI distributor? My boat came with the stock MPI wire feeding the DUI. I took that wire as a trigger for a relay and used 12g to feed it and picked up 500rpm. What gap on the plugs?

daleroger 08-23-2019 07:44 PM

36 degrees,,,full in at 2500 I believe

daleroger 08-23-2019 07:45 PM

mid range seems good

daleroger 08-23-2019 07:48 PM

will check fuel pressure at both tomorrow,,,,,,,,36 degrees timing

Tinkerer 08-23-2019 07:51 PM

I had two 509's with the 741 cam and I thought they could use a little more cam.
You might be running out of cam, that and the heads are a little big. I am running AFR 357's on a 598 solid roller.

daleroger 08-23-2019 07:56 PM

plug gap is .055 as dui recommended, ( I thought it was big ) ran stock wire from ignition to trip a 35 amp relay , #12 direct from the battery to the relay then #12 to the dist
Same prop, 21p bravo 3 blade
I should have consolidated the answers,,,,,sorry,,,,,,


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