Catch 22 on engine choices

[tegwin]

Just going to air the thoughts going through my head to see what people think...

I have an almost standard 2500m... Its not a concourse queen, but its not bad!

Although its fun to drive it lacks any punch to make it feel anything special... My daily driver is quicker...


I have been offered a 3.5L Rover V8 for not much money and I should be able to find a nice 5 speed gearbox.

The extra grunt and the noise would be fantastic, but is it totally sacriligious to remove the (relativley) rare 2.5 straight six in favour of the V8?

And has anyone seen an M fitted with the rover V8?? Are there any photos that show exahust locations etc?

Am I mad, or does it make sence?

[pumpkin]

It makes much more sense to fit a SBF which is narrower than the RV8 or the GM small block. With Aluminium heads and a T5 gearbox the SBF is considerably lighter than the Triumph. Because it is narrower than the other V8's it is easier to set the Ford V8 back far enough in the frame to have a 50 / 50 weight distribution and the exhaust can drop down beside the block instead of having to come up and over the engine and down in front. Ample power is available from any of them.
Even if the engine is free it will not reduce the cost of the job much.
It will cost twice as much as you think and take twice as long to do the job well!
Good luck!

[tegwin]

What do you mean by SBF?

[Grantura SWE]

My guess is SMF = Small Block Ford, meaning 289 or 302

[Alex]

A friend of mine fitted a Rover V8 into a 3000M. It involved quite a lot of custom chassis alterations in the engine bay. Unfortunately it was written off at Pembrey circuit.

[eric0]

How about a straight 6 out of a Vauxhall,Jag or BMW? They'll be giving them away down the breakers including the box and you may be able to use the standard engine management. They will all have the same if not more power than the 1950's RV8. Buick thought it had had it's day in 1968 when they sold it to Rover.

Edited by eric0 on Friday 29th May 15:40

Edited by eric0 on Friday 29th May 15:41

[Terminator]

I'd fit an Essex V6, of the 3.4 variety. No chassis mods and more power than a standard 3.5 RV8 too.

[Slow M]

tegwin said:

I have an almost standard 2500m... Its not a concourse queen, but its not bad!

Although its fun to drive it lacks any punch to make it feel anything special... My daily driver is quicker...

All aspects of car design are based on a set of compromises.
What are your parameters?
Consider what you desire in the way of:
Speed
Comfort
Reliability
Cost
Track day effectiveness
Fuel economy
Daily drivability

BTW, in my book, the sound you can get from an inline 6 with a decent exhaust is hard to beat.
Have you considered a warming over of your existing engine?
Webers, cam, exhaust, head work, ignition, exhaust system, overdrive transmission,

Good luck,
B.

[tegwin]

Slow M.

I already have twin 2" SU carbs... Fitting webbers would be expensive for little gain. The headers are 3-2-1 tubular stainless and the cam I believe has been changed by the previous owner. It is running standard ignition though.

Maybe I have the tuning badly setup or something because it just doesnt feel that fast!

I would LOVE to fit a supercharger to the 6pot, but once you have spent the money on that you might as well have spent it on a newer engine....


The straight 6 BMW engines take up quite a bit of space due to their lean angle....

There is always the straight six from a supra... but they are silly money!

[Slow M]

tegwin said:

Slow M.

I already have twin 2" SU carbs... Fitting webbers would be expensive for little gain. The headers are 3-2-1 tubular stainless and the cam I believe has been changed by the previous owner. It is running standard ignition though.

Maybe I have the tuning badly setup or something because it just doesnt feel that fast!

I would LOVE to fit a supercharger to the 6pot, but once you have spent the money on that you might as well have spent it on a newer engine....

IS YOUR COMPRESSION RATIO RAISED?
There are a number of heads available, should be a large port similar to UK PI model.
For raised performance it needs big SS valves with bronze guides.
There's a guy here in the US, Richard Good http://www.goodparts.com/ , who does a nice triple carb manifold for SU/Zenith Stromberg.
Regardless of twin or triple, fuel needles should be looked at when cam is changed.
Get a re-curve kit into your distributor, if you're not proficient, have a pro install it and set the timing.

Are you thinking of swapping for a stock or modified engine?
Any new engine will require new exhaust, driveshaft, ........
Any modifications add cost over and above.

Consider that above 350/400 crankshaft horsepower you'll have to consider safety and look at replacing diff if you have the TR6 unit and the remaining pieces out to the rear wheels, especially (from what I've been told) the stub axles.

B

Edited by Slow M on Friday 29th May 18:30

[The Surveyor]

tegwin said:

but is it totally sacriligious to remove the (relativley) rare 2.5 straight six in favour of the V8?

In my opinion, Yes. If you drop in any non-standard engine it'll cost you a fortune as well as giving you a car that's worth less when you've finished (one-off's put most buyers off IMHO). If you want more grunt, sell the 2500M and buy a V8 engined TVR. A nice V8S would cost you less overall and would retain some of the 'm's looks:-

http://www.pistonheads.com/sales/1055300.htm

Just my opinion but i'm not a fan of chopping about nice old cars

Paul

[heightswitch]

The Surveyor said:

tegwin said:

but is it totally sacriligious to remove the (relativley) rare 2.5 straight six in favour of the V8?

In my opinion, Yes. If you drop in any non-standard engine it'll cost you a fortune as well as giving you a car that's worth less when you've finished (one-off's put most buyers off IMHO). If you want more grunt, sell the 2500M and buy a V8 engined TVR. A nice V8S would cost you less overall and would retain some of the 'm's looks:-

http://www.pistonheads.com/sales/1055300.htm

Just my opinion but i'm not a fan of chopping about nice old cars

Paul

Totally agree with this. a triumph 6 can be tuned to give lots of HP at a price and also sounds epic. a Powder Blue TR5 is currently winning the CSCC Swinging 60's series overall at the mo and it fabulous to watch and listen too.

If you want the basis of a 5000M then really you need to start with a 4HU rear ended car IE a 3000M

an early 2500M is a rare thing with not many left so should be cherished.

a Rover v8 is a non starter since unless you are buying a proper big capacity and big money motor you will essentially fit something with a lot less Hp than the TR unit. Your problem is that you have a US federal spec engine. You have 2 options either Fit Fuel injection or go to triple webbers with big head and valves. if you are baulking at the cost of tuning your existing engine which can give an easy 200hp then you are in cloud cuckoo land thinking you can transplant a/n other!! transplants are not cheap.

The most cost effective bang for buck would be a SBF failing that a modern 2.0 duratec

Neil.

N.

Edited by heightswitch on Friday 29th May 19:14

[stainless_steve]

Just to even it up a little,it's your car do want you want with it, i am

[tegwin]

The RV8 engine weighs less than the TR unit and has (I believe) 160hp? The conversion, realistically with new propshaft, zorst, wiring etc could be done for around £650 if I do all the work myself.

So for that money what is the best way of "encouraging" the TR straight 6 to feel a bit more angry?

Its a bit of a pain not knowing what exactly the engine spec is to start with, but if I go on the proviso that it has a "sporty" exhaust and some big carbs... where should I be looking to improve?

[GAjon]

Your post title says it all really, it is catch 22.

However, it might cost a little more but, one of the best sounding TVR's I've ever heard is a well tuned Triumph 2500.

If you choose to transplant, you no longer have a TVR 2500M.

Your car, your choice.

But seeing as you asked, I would tune the engine you have.

Good luck.
John

[tegwin]

I think part of the problem for me is the unknowns of the TR engine... its seriously old tech.... I am too used to modern engines that look after them selves and dont wee wee oil all over the place!!

A few articles I have read suggest a supercharger on a standard engine with a carb can see 150hp.... but I would imagine fuel injection and a decent cam/compression might be better....


You are quite right though... I could stick in a modern 4 pot (zetec/S2000 etc).. But it just wouldnt be the same car that I have a love hate relationship with.... it would be a compromise..

[heightswitch]

tegwin said:

I think part of the problem for me is the unknowns of the TR engine... its seriously old tech.... I am too used to modern engines that look after them selves and dont wee wee oil all over the place!!

A few articles I have read suggest a supercharger on a standard engine with a carb can see 150hp.... but I would imagine fuel injection and a decent cam/compression might be better....


You are quite right though... I could stick in a modern 4 pot (zetec/S2000 etc).. But it just wouldnt be the same car that I have a love hate relationship with.... it would be a compromise..

And a 50's designed ex buick is a modern engine?

Tegwin you have potentially a very fast very tourqey engine in the engine that already lives in the car. as stated you have a US federal spec low compression engine. In fuel injected form a std UK spec TR6 gives 150hp. they can be tuned quite easily to 200hp or there abouts beyond that you need to buy steel componants.

If you seriously think you will end up with anything worthwhile at 3.5 litres capacity for £650 expenditure then I fear you will be very disapointed and also spoil a nice car.

If you seriously want a V8 M then you would be better of chopping yours in and buying a 3000M car. This way the correct axle which wont be pulled from the mounts will already be there.

I am the last person to put a downer on anyone modifying a car but in my opinion If you are going to modify then you do it properly. £650 would be better spent on a better high compression head, extractor manifold and some SU's There is a lot of second hand triumph stuff out there for sale

There are lots of hurdles to overcome putting V8's in little cars and believe me £650 won't do it, not properly leaving anything worth selling on anyhow. the rover is also the very last engine I would put into the car.

Front suspension spring and damper rates
Exhaust manifolds
Prop
gearbox mount
Engine Mounts
Diff replacement
New Exchaust
New steering linkages
Chassis modifications

Are just some of the things you will need to do to make it all work properly

There are hundereds of little jobs that all add up to a day each when you are working through a transplant.

Neil.

[heightswitch]

http://books.google.co.uk/books?id=v9Vkqp4tFEEC&am...

Some bedtime reading for you tegwin.

Neil.

[TVR_owner]

Extra power from your existing engine will not be cheap and will cause gearbox and clutch problems very quickly. You will need to uprate suspension, brakes and cooling unless thats already been done.

My advice would be to enjoy as is or sell and buy something nice and quick that is already been fettled - a nice M Turbo perhaps?

[Slow M]

tegwin said:

So for (£650) what is the best way of "encouraging" the TR straight 6 to feel a bit more angry?

Find out who builds their own race motor successfully, check with the Triumph club.
Use a dial indicator to “read” your camshaft. Write down the info. Best cam I had in mine was the Piper Cams 285/2.
Pull your head and determine if it’s the big port version. If it is not, put it on a shelf and look for one. Compression ratio is traditionally raised on these motors by shaving the head. Either determine the cylinder head thickness and see if it’s been reduced to any great degree OR CC your head and establish the CR. If you have the big port head, look to see if your guides have been upgraded to Bronze. Check to see if you have large valves installed.

Look for around 10:1 CR in final form.

I think a part of the "angry" feel you're looking for is the sound. I had dual 2-1/2" intake Flowmaster mufflers behind a 6 into 1 into 2 header and EVERY auto enthusiast who heard it LOVED it.

tegwin said:

not knowing what exactly the engine spec is to start with, but if I go on the proviso that it has a "sporty" exhaust and some big carbs... where should I be looking to improve?

3-1.75” SUs.
http://www.goodparts.com/shop/index.php?categoryID...

tegwin said:

I think part of the problem for me is the unknowns of the TR engine... its seriously old tech.... I am too used to modern engines that look after them selves and dont wee wee oil all over the place!!

There’ll be a steep learning curve ahead regardless of which way you choose to proceed. That’s part of the cost. The payoff includes a lot of pride in your car and a better understanding of it.

tegwin said:

A few articles I have read suggest a supercharger on a standard engine with a carb can see 150hp.... but I would imagine fuel injection and a decent cam/compression might be better...

I know the word supercharger starts with the letters S + U -Oh did I mention...
SUSUSU

Tegwin, the most important thing to think about when considering a conversion is that your car will be unuseable for quite a while. If you choose to modify what you have, you can replace one thing at a time and drive your car in the interim.

B.