smallblock re-power
 

I am re-powering my 1978 233 formula, currently it has twin 350's. I was going to rebuild to 383's , but have been given an opportunity to use LS6 GM crate motors. It sounds too cool to be true! But I am concerned about the torque curve and where to get exhaust, and cooling system. I'm very excited about the possibility if this engine pkg. Any opinions good or bad would be greatly appreciated.

Re: smallblock re-power
 

Those would be very cool. I'm thinking that the R&D required to marinize them and make them work would not be worth the cool factor though. Exhaust alone would be a huge project, and once they're done, would they work well enought to not reduce the power and torque. Would the EFI mapping meet the requirements of marine use?

It'd be a HUGE project!

Re: smallblock re-power
 

Thanks for the comments! The exhaust is my major concern. If I have to I can get a buddy of mine to fab. it. He makes custom stainless exhaust for GT cars. I also have another friend who can tweak the ECU. But with friends, this type of stuff takes huge time and calls in big favors! Even if I spent a season tuning I think it could be worth the effort. I don't know what it would take to marinize the engine. Its all aluminum and I run in fresh water.

Re: smallblock re-power
 

Closed Cooling system would allow the Aluminum to last. I perfer displacement. My choice would be 383's. I repowered an 1983, 18' Formula with 260 HP to 406CI small block with annodized aluminum heads. 62 mph to ~80 with the change. Way too fast for the hull. Detuned by converting from solid lifter cam with roller rockers to smallish hydraulic cam speed back down to 62 but with killer torque. Went from not wanting to plane with moderate load to pulling right up no matter how heavily loaded, and how heavy the skier (S). 10:1 compression with Brodix heads and dual plane intake and 750 CFM carb. Went from 23" 3 blade cleaver to 27" 4 blade hydromotive (drive killer). cruise RPM dropped from 3000 to 2100 rpm for identical speed. (Closed bow boat)

Re: smallblock re-power
 

I like the idea of a closed cooling system for the aluminum engines. What size of a heat exchanger would I need? I agree the 383 would make more torque than the LS6. But I think the weight savings might be be worth the 50 or so ftlbs I would be giving up. How much RPM can an Alpha take? The LS6 has good power up to 6000 RPM. That would be a shame to have to de-tune an engine!

Re: smallblock re-power
 

Check out the small blocks at worldcastings.com . It would be cool to put together a 454 sbc. Talk about a drive killer. Doug

Re: smallblock re-power
 

I like the LS6 idea. You will have to change the camshaft as part of your marinization. Does your ECU require an oxygen sensor? That may take a computer guy to eliminate.

The exhaust shouldn't be a problem. An adapter plate is all you would need 3/8" steel. I've uses big chief headers on standard big block stuff for years.

The closed cooling system is available right from CP Performance or out of the the back of the Yacht Trader.

Re: smallblock re-power
 

kiss, keep it simple stupid, live by this mantra. i built a 383, it was a monster for torque. i used a new (no core needed) scat cast steel crank ready to drop in the 350 block for around 200.00 some reconditioned 5.7 oem x rods from smmit about 100.00 per set. trw forged flat tops, oem cast iron 882 large chamber heads and a doug herbert 550/550 lift 245/255 roller. it made ungodly torque from 2 grand to 7500 where the rev limiter kicked in. i used a single plane int. with 750 dbl pumper 4150. cheap power and it ran nice n cool. go for the 383's or 388's @.030

Re: smallblock re-power
 

Thanks! I understand the KISS rule quite well, but if there is a way I can be as different as possible I will, I haven't ruled out the 383's yet! I will deal with the obvious problems before I make a desicision. about the LS6-any recommendations for cams? I have a guy that can work miracles with the ECU. Are the Big Chief headers cooled? Where can I get the headers? Thanks alot I am excited about the LS6's , so I hope I can make it happen!

Re: smallblock re-power
 

Tom Stolarz @ WPM Racing has an LS6 based motor in a 23' WPM Cat and according to him it is pretty awesome! I think his makes close to 600 HP. I am sure he would be glad to offer some assistance and probably has necessary parts available for marinizing these. :D

Re: smallblock re-power
 

I know of a source for marine fuel injected 320HP/350s complete with all accessories. Ready to drop in and run...
About 5K each... :D
Send me an e-mail if interested.
[email protected]

Re: smallblock re-power
 

If the reason to use the LS6 is 1) weight, and 2) "cool factor", I think you'll find:
1) You'll never notice the few extra pounds in a 78 Formula
-and-
2) The "cool factor" will be quickly overcome by the "frustration factor" of getting the LS6 to work.

383 all the way, and be careful with your drives.
Gary

Re: smallblock re-power
 

One of your biggest problems could be getting around the alphas shift interupter switch.......It momentarilly kills the motor to allow the drive to shift.....the drive will grind itself to death if you dont have it installed.......a friend of mine tried to put a TPI on his smallblock/alpha .....couldnt make that part of it work......motor ran great though.......bravos dontahave that however..........

Id go 383 and get out on the water.....personal choice....doug

Re: smallblock re-power
 

Wait for this........should be available later this year!!!
FOR RELEASE: 2005-03-22



Most Powerful Small-Block Ever - Available in a Crate

DETROIT - Chevrolet unveiled the 2006 Corvette Z06 at Detroit's North American International Auto Show in January, and now GM Performance Parts is unveiling the crate engine version of the LS7 engine that powers it. This latest Z06, billed as "the fastest, most powerful car ever offered by Chevrolet and GM," has enthusiasts looking for that kind of power in a crate engine. GM Performance Parts is ready to end that search as it offers the LS7 (P/N 17802397) at GM dealerships and Authorized Centers, nationwide in August.

This small-block V-8 dreams big, displacing big-block cubic inches at 7.0 Liters (427 cubic inches) and big-block power at 500 hp at 6200 rpm. It also benches 475 lb.-ft. of torque at 4800 rpm. Helping to create its high power and high revving capability are details such as cylinder heads with computer numerical control (CNC) intake and exhaust ports and combustion chambers - which creates ports with surgical accuracy for maximum power production. In addition, the intake valves and connecting rods are made out of high-strength lightweight titanium.

The LS7 engines are assembled by hand at GM Powertrain's new Performance Build Center in Wixom, Mich.

Pricing will be announced mid-summer; however, early estimates indicate that the GMPP LS7 crate engine will sell for well below the cost of comparable custom-built aftermarket engines.

Enthusiasts who must have the latest technology, maximum horsepower and the largest production cubic-inch displacement small-block ever built will be able to purchase the LS7, as well as other GM Performance Parts crate engines, blocks, heads and components, from GM dealerships or GMPP Authorized Centers nationwide. Following the release of the LS7 in a crate, GMPP will offer select parts, such as the crankshaft, connecting rods, cylinder heads and valves separately, and in kit form. To locate the closest GM dealership or GMPP Authorized Center or dealership, call 1-800-GM USE US or visit www.goodwrench.com.

General Motors (NYSE: GM), the world's largest vehicle manufacturer, designs, builds, and markets cars and trucks worldwide, and has been the global automotive sales leader since 1931. More information on GM can be found at www.gm.com.

LS7 specifications:

Part number: 17802397
Horsepower: 500 (373 kW) @ 6200 rpm
Torque (lb.-ft.): 475 (644 Nm) @ 4800 rpm
Engine type: Cam-in-block 90-degree V-8
Displacement (L/cu in): 7.0 / 427
Bore x stroke (mm/in) 104.8 x 101.6 / 4.125 x 4.00
Block: Cast aluminum with pressed-in cylinder sleeves and 6-bolt, forged steel main bearing caps
Crankshaft: Forged steel
Connecting rods: Forged titanium
Pistons: Cast aluminum
Camshaft type: Hydraulic roller, 15 mm (.591 in) lift (intake and exhaust)
Cylinder heads: CNC-ported aluminum; 70-cc chamber volume
Valve size (mm/in): 56 / 2.20 (titanium) intake / 41 / 1.61 (sodium-filled) exhaust
Compression ratio: 11.0:1
Rocker arms: 1.8:1; offset (intake only)
Recommended fuel: Premium required. 91 octane minimum
__________________

Re: smallblock re-power
 

The LS7 sounds very impressive! With the extra glass work I am having to do I might end up waiting. The reason I am considering a LS6 is I can get one cheap(has 2.5hrs on it), and pay full price for the other. The shift interrupter switch should be able to switch off the ECU, to accomplish the same effect as the stock set up. If I had copious quantities of cash I would wait for the LS7!!

Re: smallblock re-power
 

I dont understand the cast pistons, but switching over to forged is no biggie. I'm planning on one for my C5 Vette, but will have computer/ecm problems I'm sure. Waiting to hear the $$$$

Re: smallblock re-power
 

The exhaust could be made by CMI in Wisconsin. They could make you a set of header with your bolt pattern in the flange custom no extra charge. Or you could try to find a used set and have a local machine shop make the adapter for you.

Being differant is a good thing. The easy way is just that EASY. Put your mind to it and get what you want.

Re: smallblock re-power
 

Thanks for the support! I will contact CMI and see what they can do for me.

Re: smallblock re-power
 

Resurected - Owen Sound!!!!!!........and your not driving a Grew....... shame on you!!!!!...... :D :D

Re: smallblock re-power
 

My dad had a mid 70's 21' grew with twin I-6's while I was growing up! I found this old formula last year and just had to have it.

Re: smallblock re-power
 

Ratman- nice sounding package.... the cast iron 882 large chamber head is a stock GM piece....... do you know what they came stock in???.....Ive got twin 89 350 mags 270hp(carb) in mine, all stock now, runs about 64-65 now................Id like to see about 400- 425hp/side to wake the thing up a bit.......but not break the bank either.........doug

Re: smallblock re-power
 

pull my trigger, the 882's were very common heads during the gm low compression years. id call some cyl rebuilders and you can probably scrounge up 2 sets easy enough and cheap enough. they come with 1.94 in i spent the cash to install 2.02 but it isnt neede for marine and 6k redline. there is a place in ft laud engine builders warehouse where i got the scat cranks for under 200 bucks is a cast steel 5140 crank and i wrung it out to 7500 all day long no problem just be sure th balance your rotating assm. ths 5.7 gives it a decent rod ratio but i think there is a place selling 6.0 ford rods resized for sbc for very little money for an even better rod ratio., doug herberts roller cams are inexspensive as were his springs and roller lifters. the trw forged flat tops through summit racing were cheap by piston standards. it idled like nice and low and made unreal torque from idle to redline. you'll love the power. ratman

Re: smallblock re-power
 

I contacted them and they said they don't make marine applications. I guess you could buy a short block and built it from there. I'd love to upgrade to 427 or 454 smalls.

Re: smallblock re-power
 

[QUOTE=ratman it idled like nice and low and made unreal torque from idle to redline. you'll love the power. ratman[/QUOTE]
thanks ratman!

Re: smallblock re-power
 

Baja Fresh- what do you got in your Cig right now???

Re: smallblock re-power
 

Stock 350's (5.7's) with Alpha's. They are pretty freshly rebuilt but would like more power. I'm a hot rod guy so I can build the motors but of course, marine stuff is a bit different than automotive. I'm thinking about using the World Castings short blocks and working my heads. Need to do plenty of research: cam, head compatability, carbs/injection etc. Anybody have any idea if this would work?