Spitfire TR4 engine in a spitfire

[trfourtune]

JAGCDN,
the tr4 engine is listed as 403 LBS. that's 150 lbs more and it is tall. the roll over moment in a corner is high.
R

 

[swift6]

Still my two cents advice;

If you want to keep the britton sports car feeling, avoid those oversquare asiatic motors. There drawback is a non-torquey engine. i.e.: they rev. high to produce H.P..
Cheers,

The smaller engine Spitfires were not exactly "torquey". The 1147 and the 1296 engines were nearly square. The 1500 was the "torquey" Spitfire engine with a much longer stroke than bore. The 2.0 used in the GT6 is also a nearly "square" engine with nearly identical bore and stroke. All much better at revving high for the horsepower they produce.

In the Ford/Lotus/Cosworth world the 1600 Crossflow and the whole range of twin cam variants of that engine are all oversquare and will rev until the cows come home. So not all 'Britton Sports Cars" were torquey. Those "oversquare asiatic motors" are spiritual successors to twin cam variants of the Kent engine (as well as the Italian engines).

 

[JagCDN]

Shawn,

It is not a matter of having all brits. cars being undersquare here, I didn't say that. But if you have look at Jag., Healeysand manys known Brit. cars, engines are undersquare and despite their sometimes lower HP, these engines are torquey. They yield decent acceleration, better than oversquare ones at low RPM.

It is why I dislike Hondas and such cars like Miata, as you have to rev. them. It is a matter of taste and explains why I prefer stock cars than F1 lawnmower type engine. And here we are speaking of a swap for a Triumph not for a Fiat Spider.

Cheers,

 

[Twosheds]

This was came from the Friends of Triumph e-mail list:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Sorry to post here but am trying to save a spitfire from the crusher
or me from a tongue lashing for buying another car

A friend purchased a 73 spitfire basket case and decided it was more
than he wanted to do. He is trying to sell it the body is pretty rust
free, has a 1500 motor. I am listing it here to try and save it from
the crusher. Any one interested contact me and I will give him your
contact information. It is in Winona, MN. I can help deliver it for
gas to anyone close.
Thanks for looking
dick ross
niteseeker@mac.com
[/QUOTE]

I don't know if Winona is close to you or not, but...

 

[swift6]

Shawn,

It is not a matter of having all brits. cars being undersquare here, I didn't say that. But if you have look at Jag., Healeysand manys known Brit. cars, engines are undersquare and despite their sometimes lower HP, these engines are torquey. They yield decent acceleration, better than oversquare ones at low RPM.

You linked the undersquare nature specifically as a key element to British Sports cars. Which is why I pointed out that the early Spitfire motors were closer to square and DID need to be revved. Unlike their torquey cousins, the Triumph TR's. Spitfires were a whole different animal than TR's.

Having a small displacement, higher revving engine is very much in character for a Spitfire. I agree that it would be out of place in a Jaguar, Austin Healey, TR or any other of the more "brutish" English Sports cars. The more nimble and lithe sports cars, like just about any Lotus, and Spitfires and GT6's can fall into this category, were much more likely to have a near square or oversquare engine that needed to be, and could be, revved quite high.

I don't use "brutish" as a slight either. Just look at the cars in my garage and you can see that I am a fan of torque.

A good part of why many engines in English cars moved well into undersquare territory as they grew in displacement was due to the tax structure on the vehicles at the time. The tax was based on the engines bore size, so the best way to improve power and displacement was to "stroke" the engines. Even the Jaguar XK Engine was an undersquare engine in the early 2.4 litre displacement(bore 3.2677", stroke 3.0118").

 

[tomgt6]

Thank you for the information. Winona is 45 miles down the road and I think I am talking with the guy already. It is a basket case and I am trying to find some time to go look at it. Some of the issues are the car was in the process of a dismantling and stuff is missing and it is going to be hard to see what is there and what isn't. Also I would like to see if the engine turns and then if I can see if I can get a compression test done but I am not sure that will happen. I understand the wiring harness has been removed.

I don't want to get a car that will be another basket case that my wife will kill me over. I would like to be able to drop this engine, tranny, drive shaft, diff and a few other parts right in and not have to rebuild it all again. If the price is right then maybe I can do it.

 

[Andrew Mace]

Both the wet-liner and "SC" engines, particularly in their original forms in saloon cars, were designed in large part for pretty decent (relatively speaking) torque across a broad range of engine speed, including fairly low engine speed. One "official" measure of their cars was for the cars to be able to accelerate from something like 10mph in top gear without undue faltering.

Yes, the earlier Spitfire engines were more nearly square than some other engines, but they didn't originate that way. The original "SC" engine was 803cc: a 58mm bore and a 76mm stroke! It took a good bit of rethinking and reengineering to get up to the nearly square 1296...and then, with nowhere else to go, they had to boost the stroke to 87.5mm to get 1493cc...and the bit of torque boost that went with that longer stroke. I think it's still generally accepted, though, that the 76mm-stroke fours and sixes rev (or potentially can rev) better than the 87.5mm-stroke fours or the 95mm-stroke 2.5 litre sixes.

Also, in tuning the 10/Herald engine for use in the Spitfire, it was much more a gain in horsepower than in torque. In simply bolting a Spitfire's twin SU carbs to an otherwise unmodified Herald engine, some horsepower is gained, but some low-end torque is lost.