Boatally Insane

iTrader: (1)

Looks like I have finally acquired enough pieces to drop it all off at the machine shop..

.....Thought I would run it by you guys and see what ya'll think...

This is going in a 24' Excalibur and will have to run N/A for this summer but plan on adding a Procharger next year as $$ permits..


I'm well aware some of the parts I'm using are not the best out there but hopefully good enough to stay together and make reasonable power..


Ok, with that all out of the way here's what I have....

....short block....
Dart big M tall deck block billet mains 4.560 bore.
Eagle forged 4.25" stroke crank turned 10 10
Eagle 6.535 rods with ARP 2000 bolts
Cleveite H series bearings.
Manley forged 2618 pistons. -20cc dish. (about 8.5:1 compression)
Sealed Power Plasma Moly file fit rings.
Pistons will be .005 in the hole..

......cylinder heads....
Merlin "Grumpy Jenkins" Iron heads.. 320cc runners 119cc chambers
2.25 in. stainless intakes 1.88 inconel exhaust
Fel Pro .041" MLS head gaskets


It'll be a Cam Motion hyd roller cam & lifters
Something about 240in 248ex dur. .630" lift on a 114 lobe center
(waiting to get the heads looked first)

.... Intake / Exhaust.....
Cutler EFI intake with 42# injectors (for now)
Fast throttle body Mefi 3 ecm
Early K/E (Drake) manifolds dry to the tips.

Hoping for 600hp at 6000 rpm N/A but don't know if the heads are gonna cut it...

Now a couple questions I have....

Will doing a bowl blend on the heads help much at all ?
Speed Pro suggests .006" per inch of bore for ring end gap supercharged which comes out to .028" is this enough for supercharged marine use ?
Manley suggests a piston to cylinder wall clearance of .006 for ALL BBC applications is this sufficient ?


Any advise / input is greatly appreciated...

Thanks,

Doug

adk61

iTrader: (5)

I would run a stainless top ring, .026" - .028" and .028" - .030" is good on second ring, however your .006 is a bit tight... I would run closer to .008 piston/wall... and i would hope you're running at least a 2 stage pump, blower engines require tons of water volume, you'll also need to bypass water from rear of intake manifold to allow sufficient cooling of rear cylinders... good luck with your build, feel free to call if you want advice... Alan 905-722-6684

Boatally Insane

iTrader: (1)

I even called manley and that's what they recommended

My machinist felt that was a bit tight as well, just wanted to see what other are running....

Thanks !

Doug

rmbuilder

Doug,

A 2618 Manley piston, in a fresh water cooled engine, with ~ 150º temp, at the correct gauge point distance, .006" is the correct piston to wall clearance.

Bob

Boatally Insane

iTrader: (1)

Interesting...


Just thought it was odd that Manley suggests the same clearance for a N/A street engine as a supercharged marine engine..



I'm used to running JE stuff which requires additional clearance for supercharged & more additional clearance yet for cold water marine use..

Doug

adk61

iTrader: (5)

yes odd it is... remember these clearances provided are minimum requirements, more often than not you will see a builder increase depending on application, especially supercharged and cold water marine... IMPO can't beet the JE piston... reliable to a fault!!