3.6 GT powerhead details

[Hillclimber]

Hello

I am the mad "Hillclimber" from England building a race car using a V8 two stroke with CVT transmission.

I have just purchased two 1986 3.6 GT powerheads from a fellow in Las Vegas and these arrive in the UK in October, Type E300CXCUR. I assume the C is counter rotation i.e. anticlockwise looking at the flywheel ? I will build one engine from the two, serial numbers are consecutive. Initially in standard form and when all running OK modify other block for expansion chambers, reporting etc.

I have spent many hours searching the S & F Forums for technical details of these engines BUT cannot find the details I need to select the correct CVT and other components.

What I need are:

A power - torque -rpm curve for the standard engine

The port opening/closing times and/or degrees on crankshaft, and the open areas of the ports

A power - torque - rpm for a modified engine with about 400+ hp

Has anyone manufactured successful expansion chambers for this engine? If so dimensions appreciated.

Has anyone experience of running the engine with horizontal crankshaft i.e. lubrication problems with bearings?

I am one set of carbs missing - Any for sale

Where is best supplier of spare parts and/or race components?

Any help - guidance of where to get the information appreciated. BRP/Merc/Invinrude not helpful on my questions.

Peter

[powerabout]

How will carbs work when the engine lays down?

[PanRonnie]

i don,t want to rain on your parade but i can save you a lot of time and money
you will not be satified with the result off suchs a conversion
3 years ago i was contacted by somebody from england who had build a mercury 2.5 on his drag bike and installed a DTA S80 ecu
i helped him get the thing running but he never showed up in any drag racing pictures

a 2 liter engine https://www.youtube.com/watch?v=22kPfqRmShI
but if i were i would install one off the aluminum crate engines
http://www.chevrolet.com/performance...gines/ls3.html
or you can ask him
https://www.youtube.com/watch?v=mrhsUXnodfw

[powerabout]

Boosted 4 strokes how about NA engines that are 100hp/ltr which is easy for an outboard.

[Hillclimber]

If I cant cut and turn 90 degrees, then I will use 8 Mikunis

[Hillclimber]

Here is a Hillclimb car built in Spain, won the championship, then 2 strokes were banned next year! Its a 400hp two stroke or nothing. The attached thumbnail shows carbs which can turn 90 degrees.

[Hillclimber]

I think this could be him - John Finch?
Attachment 351939

[STV_Keith]

Maybe Racer (Al Stoker) will chime in as he was an OMC guru and had a dyno. I have dyno charts of my Monty Racing built motors, but knowing what Monty did to them, I doubt the curve is the same. Find my thread in the Outboards for sale section. Pretty sure I posted a dyno chart in there.

[powerabout]

which way will the crank be in your car?

[atclen]

Here you go !





Anything can be done if you got time and money !!

[Hillclimber]

Horizontal crank probably with carbs/EFI at the side.

[powerabout]

ok so lay on side with one head high and then rotate carbs 90 degree?
Just go EFI, build a plate to hold the reeds and injectors with a flange to hold a plenum ( or put injectors here) with a few throttle bodies in it
Hopefully Racer chimes in about top bearing lubrication?

[racer]

Peak output on a stock 3.6 powerhead was generally right around 6200 with a couple I saw 6500, how well the intake ports were matched made the difference. The exhaust has enough height to make peak at 7500 but does benefit from some added width. To make 400 without pipes it will need a fair amount of work including fingerports.

A horizontal engine will need to keep the mains oiled as normally the oil falls down the crank and is pumped back up to the top main with a one way valve in the line. Drag engines the upper lasted better with main being oiled good prior to starting. I would want to see some angle with the lower main below the upper so oil will make it down in order to be pumped back up, this is how we use to run a V4 in a midget race car.

Keith was? memory is not what it use to be. Torque curve does not move much below 5500 unless a lot of compression and/or really big ports.

When I can get to dyno records that I still have will post a few numbers, most went with the dyno when I sold it to Sea Way so they had good starting points as they learned the dyno.

[powerabout]

Here was/is a way to add EFI as a bolt on ( Taylor Marine) but you can also get other companies that put an injector in a throttle body ( in the UK)
The 2 piece inlet is an Al Stoker ( Racer) showing that if you build something to hold the reeds then you are free with the inlet.
One of my buddies in OZ milled a stock inlet down to that level then made a custom front to hold the carbs.

[Hillclimber]

Hi Powerboat
Thanks for the pictures etc. Do you know if anyone has tried 8 or 16 injectors directly into the transfer ports avoiding the need of reeds? probably with a supercharger to boost/correct/control the fuel - air mixture? I am only "Thinking" at present since I do not have an engine in front of me to see whats possible/feasible with the ports. On one of my two stoke projects I added extra external transfer ports which dramatically improved power - torque output. I may have to consider an oil pump delivering oil directly to all bearings plus cylinder spray, all monitored by 8 EGT and/or air/fuel sensors, rather than a 25-50 to 1 premix. Smoke generation using premix is one of my problems as is noise generation.
In my type of motor racing, I only run between 1 to 2 minutes at maximum power, so the supercharger can be driven by a compressed air supply avoiding any parasitic loss of power from the engine. I will also fit an electric water pump. Now I am onto calculating the surface area of the radiators I need to fit. What is the optimum working temperature of the engine? Lots of questions before I start the project.