Cantilever Mounted Engine Installation

[Captain Ahab Jr]

I'm sure I've seen a picture of this done on a Baja sandrail racer where the engine is mounted off a chassis frame/plate between the engine and gearbox ie no rear engine cross brace support

I'd like to do this but I'm a bit concerned the crank case will flex too much and cause internal engine running clearance problems

Has anyone seen this done or can post up a picture. All comments and thoughts welcome

[wayner]

Four cylinder air cooled Porsche engines just hang off the transmission with four bolts. I'll bet the factory knew the 6 would break the transmission case if the engine wasn't supported at the other end

[safe]

Originally Posted by wayner

Four cylinder air cooled Porsche engines just hang off the transmission with four bolts. I'll bet the factory knew the 6 would break the transmission case if the engine wasn't supported at the other end

Like in a 912 you mean? No, they don't.

[wdfifteen]

Originally Posted by safe

Like in a 912 you mean? No, they don't.

Like a 356. Which do.

[sc_rufctr]

Regardless... Why do this?

[Flieger]

You mean like engine subframes for light aircraft? Could you modify one of those?

[Flieger]

Originally Posted by sc_rufctr

Regardless... Why do this?

He's building a tubeframe car midengine with 911 bodywork last I heard.

[Captain Ahab Jr]

Nearly 2 years later I found it, not a Baja sand rail but a Pike Peak hill climb racer

The Amazo Effect: Race Car Of The Day: Bruce Canepa Pikes Peak Porsche

[Quicksilver]

I have the strange feeling that the reliability concerns in a car with a total running time of about 12 minutes is probably different then almost any other application.

[stownsen914]

Here is an old for sale ad here on the forum for a 914/6 racecar that has the trans supported at both ends.

914-6 RHD Race Car

Here is another 914/6 racecar that has a Hewland trans, and it looks like it has the trans supported only by the engine (transverse mounting plate similar to the one in link above). The pic that shows it is a little ways down in the thread if you scroll.

914World.com - The fastest growing online 914 community!

Scott

[Trackrash]

I WISH my Baja Bug had a rear engine mount like a 911. Hanging the motor off the trans was fine with 40 hp. Not so good with 150 or more.

You will notice that the rear 911 engine mounts are WIDE, extending the width of the engine compartment. That is an excellent way to control the engine's torque.

[Mike Billings]

You are correct, Captain. An expert told me that the central part of the rear engine carrier was important to bearing life.

Maybe Van knows whether these nice aluminum ones are available?

[stownsen914]

Personally I prefer to shock mount my engine/tranny assembly to minimize the chance of twisting the engine and stressing the case or any internal components. I've heard at least one case in which a crankcase was cracked while bolting up a motor/trans to solid mounts (granted that may have been due a bent chassis or engine crossbar). On the flipside, the factory felt solid mounting was acceptable enough to do so on the 962, and use the engine/trans assembly as a stressed member as well - they mounted the rear suspension to the trans case.

[Flieger]

It's not fully stressed. There is a frame structure to add rigidity. Fully stressed would be like a Cosworth DFV F1 engine.

[Captain Ahab Jr]

Holy thread resurrection Batman!

I knew I'd seen a picture, just took me over 4 yrs to remember where

normally aspirated installation


turbo charged installation later development, you can see the polish stays supporting the front end of the engine


more about the car
https://jalopnik.com/the-raddest-pikes-peak-racer-is-a-porsche-powered-hot-r-1827075477

[Jonny H]

Spotted that car at Bruce’s place last year whilst messing round with some old race car.

[Captain Ahab Jr]

Very cool Jonny, you get to mess with all the cool stuff!

Next time you're out there or if anyone else is visiting Canepa can you take a picture of the underside of the engine just so I can confirm it is cantilever mounted

Cheers,

IB,com WC doppelganger

[Jonny H]

^ Well we just put CDI+ on his 935. I’m told it’s making 900 HP - too much for the clutch which exploded on the dyno!

[nathanbs]

I can comment that on a type 1 VW that had approx 150 hp it got tremendous wheel hop attributed to the flex. A simple “traction” bar that rested under the rear of the engine and was secured to the body of the car prevented the flex and eliminated the wheel hop

[Ora]

Now that is a badass rail!!..wow!!

Originally Posted by Jonny H

Spotted that car at Bruce’s place last year whilst messing round with some old race car.