I have a chassis conundrum and I need some assistance.

[LordTwaddle]

Hey all, I thought I’d use the GG forum to get the widest audience for this question.

My query is this: how much horsepower can an Austin Healey 3000 chassis take?

I’m not talking about the engine itself, I’m specifically asking about the chassis, how far can you push them before they run the risk of damage? I ask because I am about to take on a very rare 1967 Trident Clipper project and I need to make a decision on the engine. Stock the Healy put out between 100-150hp, the original V8 Clippers had between 200-270hp, how much higher do I push it and what would I need to do to the chassis to take an extra few ponies?

If 270-300hp is top-end then I’ll stick to a stock 289 HiPo V8, however if it can squeeze more then a 302 Ford Performance unit with 350hp might be in order, if the sky is the limit then a Roush 427 with 450hp might be an amusing choice.

[996TT02]

Think you will reach the undrivability / can't use half this power limit way, way earlier than any chassis damage. On the way there you will trash the diff, rip the rear axle out of its location, and if unchanged make mince of the gearbox internals and possibly also externals. Even crude old and not so old yanks which can take the power are really quite incapable of putting down half of it effectively let alone something designed in the stone age for maybe 150 wobbly horses.

[LordTwaddle]

996TT02 said:

Think you will reach the undrivability / can't use half this power limit way, way earlier than any chassis damage. On the way there you will trash the diff, rip the rear axle out of its location, and if unchanged make mince of the gearbox internals and possibly also externals. Even crude old and not so old yanks which can take the power are really quite incapable of putting down half of it effectively let alone something designed in the stone age for maybe 150 wobbly horses.

I would compensate for whatever extra power I did decide to go for, I’d make sure I’d have a gearbox, diff and axel fitted plus better brakes and suspension components. Ideally I’m just looking for more effortless motorway cruising as it’s a car I’d look to put a lot of miles on when it’s finished.

[Equus]

Your tyres will act as a 'fuse'.

The AH 3000 is on cart springs and live axle at the back - it was crude technology even when new - so I'd expect the next limitation you'll run into will be axle tramp, for which you can fit a tramp bar kit.

Try talking to Denis Welch.

[LordTwaddle]

Equus said:

Your tyres will act as a 'fuse'.

The AH 3000 is on cart springs and live axle at the back - it was crude technology even when new - so the next limitation you'll run into will be axle tramp, for which you can fit a tramp bar kit.

Good shout. I’ll have the chassis completely re-done so I’ll have plenty of opportunity to upgrade where needed to cope with the engine choice, from factory Trident barley touched the chassis when adding the 289 V8 over the BMC 6cl.

[Tabs]

For a minute, I thought Chassis was returning (older members will remember)!

[ndtman]

https://forum.retro-rides.org/thread/36207/chevy-3... links to a Chevrolet engined Healey. I think I've seen it on here as well.

[john2443]

A friend has what was a 100/4 (now a 100/8 that's close to 500BHP/ton, but it's had lots of mods. Pete Farmer built it.

There's some stuff about V8 Healeys here https://healeys.proboards.com/board/8/modifieds

[Lotobear]

I am curious as to why you would wish to do this; would you not be better keeping the car as an original but anachronistic old sports car and seeking out a HMC replica?

[AW111]

I'd say a warm 289 will give you all the power you'd use, while staying close(r) to the original.
It's also the lightest choice, unless you go SBC.

[aeropilot]

LordTwaddle said:

Hey all, I thought I’d use the GG forum to get the widest audience for this question.

My query is this: how much horsepower can an Austin Healey 3000 chassis take?

I’m not talking about the engine itself, I’m specifically asking about the chassis, how far can you push them before they run the risk of damage? I ask because I am about to take on a very rare 1967 Trident Clipper project and I need to make a decision on the engine. Stock the Healy put out between 100-150hp, the original V8 Clippers had between 200-270hp, how much higher do I push it and what would I need to do to the chassis to take an extra few ponies?

If 270-300hp is top-end then I’ll stick to a stock 289 HiPo V8, however if it can squeeze more then a 302 Ford Performance unit with 350hp might be in order, if the sky is the limit then a Roush 427 with 450hp might be an amusing choice.

Horsepower isn't so much the issue with the chassis.........its the torque output.
With a US V8 that wants to twist the chassis around the crankshaft when you wind it up (even when blipping the throttle at idle) this is where you will start to fatigue the chassis.
I'd be sticking to a HiPo 289, or 302. You might be OK with a mild modern 302.....but I'd forget that Roush 427

[Mark A S]

Was just going to say the same, Don't worry about BHP its the torque. If your insistent on a V8, try and tune out some torque. It will be "interesting" to drive

[Equus]

aeropilot said:

Horsepower isn't so much the issue with the chassis.........its the torque output.

But it's got to have something to twist against, and ultimately that's the grip at the tyre contact patch.

That, plus the fact that the leaf springs will wind up and tramp, should ensure that the excess torque is bled off as wheelspin before things become too much of a problem. The chassis might need reinforcing, and anti-trap bars fitting to cure the worst of the spring wind-up, but Healey competition specialists will be able to identify the weak points and tell you what to do about them.

[LordTwaddle]

Lotobear said:

I am curious as to why you would wish to do this; would you not be better keeping the car as an original but anachronistic old sports car and seeking out a HMC replica?

Good question: the car originally came as a Venturer with a 2.5l Essex V6 from factory however it has a non original 3.0l V6 now which means it’s no longer numbers matching.

If the engine didn’t need a full rebuild I’d probably keep it however by the time it’s been completely rebuilt and breathed on, for a couple of thousand more I could double the power and upgrade it to a V8 Clipper specification, future proofing the car.

[LordTwaddle]

aeropilot said:

LordTwaddle said:

Hey all, I thought I’d use the GG forum to get the widest audience for this question.

My query is this: how much horsepower can an Austin Healey 3000 chassis take?

I’m not talking about the engine itself, I’m specifically asking about the chassis, how far can you push them before they run the risk of damage? I ask because I am about to take on a very rare 1967 Trident Clipper project and I need to make a decision on the engine. Stock the Healy put out between 100-150hp, the original V8 Clippers had between 200-270hp, how much higher do I push it and what would I need to do to the chassis to take an extra few ponies?

If 270-300hp is top-end then I’ll stick to a stock 289 HiPo V8, however if it can squeeze more then a 302 Ford Performance unit with 350hp might be in order, if the sky is the limit then a Roush 427 with 450hp might be an amusing choice.

Horsepower isn't so much the issue with the chassis.........its the torque output.
With a US V8 that wants to twist the chassis around the crankshaft when you wind it up (even when blipping the throttle at idle) this is where you will start to fatigue the chassis.
I'd be sticking to a HiPo 289, or 302. You might be OK with a mild modern 302.....but I'd forget that Roush 427

A Ford Performance 302 crate engine comes with around 340hp out of the box for around £8-£10k fully built. For simplicity I’d consider one however the purity of a 289 HiPo is tempting but they are harder to find.

[Gavin0478]

Why not just go the full hog https://www.pistonheads.com/gassing/topic.asp?h=0&...
It would be exciting haha.

[LordTwaddle]

Here is the car in question, it’s a hand built TVR derived fibreglass shell on top of a Healey 3000 chassis, most had Triumph underpinnings which is what makes this one rare/special.

[Turbobanana]

Equus said:

Try talking to Denis Welch.

About 6 years too late, I believe.

[Lotobear]

LordTwaddle said:

Good question: the car originally came as a Venturer with a 2.5l Essex V6 from factory however it has a non original 3.0l V6 now which means it’s no longer numbers matching.

If the engine didn’t need a full rebuild I’d probably keep it however by the time it’s been completely rebuilt and breathed on, for a couple of thousand more I could double the power and upgrade it to a V8 Clipper specification, future proofing the car.

Ah, that will teach me to read the bloody post properly!

...I assumed we were discussing an actual AH 3000

[Equus]

Turbobanana said:

About 6 years too late, I believe.

Alright, speak to Denis Welch Motorsport, if you're splitting hairs.