Triumph Sports Cars

VERY nice! Would love to see detailed photos/write-up for our Gallery section.

Can anyone provide any input on the GM 4.2 liter inline 6 cylinder motors? They are 270 hp stock, all aluminum, and pull-outs are in the $600 range on eBay. They came in Trailblazers and other vehicles, so there are a lot of them around. Supposedly adapters exist to mate up a T5 transmission.

Sounds like a winner to me, except they are 30" tall. Will it fit with a stock hood?

I do not think that a 30" tall inline 6 would fit under a TR6 hood. A way to check is measure the height of the existing TR6 engine.
The GM 3400 V6 I put in my TR6 is about 28" tall at the tallest point and I have about .5" clearance above it.
That engine you are looking at might fit if you remove the battery tray and shove the engine far back as possible. Doing this would entail a lot of cutting and rejigging the fire wall/transmission tunnel.

Cheers
Byron

Thank you Byron-

I have a TR250 and was also wondering about transplanting an M3 engine. The E46 S54 develops around 330 hp which is plenty for me. Looking to avoid major cutting associated with the V8 transplants. Does anyone have dimensions or more info about the feasibility of doing this?

Larry send an e-mail to Dennis Matthews, his moniker is 69 TR6. Dennis is putting a BMW straight six in his 69 TR6 and he might be able to help you on engine dimensions.

Cheers
Byron

Just a quick little tip that I use all the time.
Take all of your measurements for the new engine off of the crank centerline.
If the original engine is still in your car then base your conversion on it's crank position.
If not, lay out a straightline from the front of the car to the diffy and base your measurements on that.
Make a couple of quick cardboard engine templates based on the new engine measurements and away you go.
I've even made up a full cardboard engine and trans a few times when things got pretty tight.

Live like you mean it.
Fred

Second the suggestion by doctoreurocar about the BMW M30 engine. These used to be VERY common in junkyards, as they were installed in everything but the 3 series cars for 15-20 years. Probably lost a lot of potential donors in the wake of the Cash for Clunkers debacle here in the U.S., but these engines should still be pretty easy to find in good nick. Well cared for, they're bulletproof, simple to maintain (timing chain instead of timing belt) and turbo kits are available (even from the factory, but of course those are pretty rare on our side of the pond), plus the ECU is very simple and should represent no impediment to installation and proper setup. Think they put out a little over 200hp in stock form and the internals can handle quite a bit more if required. Only downside I can see is it's probably easier to find one mated to an automatic rather than a five-speed transmission. Bonus: one of these would look quite period correct under the long hood of a TR6 (lots of simple cast aluminum atop the engine).

The later, twin-cam M50 engine found in '90s-era 3 and 5 series cars is also common -- I think someone else suggested this, as well. Widely available, these motors are smooth and powerful, uber-solid and fairly compact. And I think turbo/supercharger setups are widely available. However, I believe at least some of these are OBD-II, so installation may be a bit more complicated. On the upside, tons of these can be found with very robust 5-speeds. Same goes for the S50/S52 motors found in M3s of the period -- more expensive but still fairly common.

Holy grail from Munich would be the hallowed S38, an absolutely brilliant twin-cam engine that was installed in E28 and e34 M5s and E24 M6s. As I recall, it's an update of the engine BMW installed in the fabled M1, which I think used a tweaked M30 block. Quite rare at this point and very expensive (five-figure rebuilds are the norm), but great power (256-286hp, IIRC) and the valve cover, intake manifold and bellows combo is nothing less than automotive engineering porn. Only available with a 5-speed (Getrag, I think). Not sure how amenable these are to a turbo or supercharger installation (and personally I wouldn't want to mess with that lovely intake setup), but If money were no object, this is what I'd want to put under the hood.

Hope these offer some food for thought ... and best of luck.

This is an old thread, but let me toss out one more possibility - The 4.0 Jeep.

Been around forever so they are avaialble and inexpensive. Rear sump, so it packages easily. Roughly 18" from crank centerline to top of valve cover and about 32" from bell face to front of harmonic damper. ~450lbs with iron head.

Stock it will make 170 to 190 hp depending on year. Edelbrock just released an alloy head that will allow you to make power well in excess of that and shed over 40lbs to boot. 200+ hp would be easy. [www.edelbrock.com]

Any V8 or six cylinder Jeep bell will fit allowing you to bolt on a T-5, AX-15 or Toyota trans, or any number of other common manual transmissions.

Several exhaust header possibilties, but the stock dual exhaust headers or manifolds work well.

On the intake side, all 4.0 engines had an ugly looking EFI but with a little imagination something better looking could be built. Same port layout as the Datsun 240Z - maybe the dual SU intake from the Datsun could be adapted?

Stroker kits are available - I think you can build these to 5.0 liters. Lots of cams available.




Edited 1 time(s). Last edit at 08/18/2015 02:52PM by MustangSix.

That jeep motor sounds like it has great potential.
If one was fitted with that aluminum head, decent headers, a mild cam, and maybe 3 Mikunni carbs I am sure you could get about 270 hp out of the engine. The thing would have lots of torque.
To fit one in the TR6 would still be a fair amount of work.
The intake and exhaust on the Jeep engine are on the opposite side of the engine so you would have to route the headers around the steering shaft.
The TR6 engine from the center of the crankshaft to the top of the valve cover is 15.5". The extra 2.5" on the Jeep engine could prove to be a bit of a problem to get it to fit under the hood.
The TR6 engine from behind the fan to the edge of the bell housing is 29".
To get the Jeep engine to fit under the hood you would probably have to cut out the battery tray and shove the engine as far back as possible.

Cheers
Byron

Just a quick update on the RB25DE install.
Engine is sitting on mounts, the drivers side is using the stock Nissan mount and is sitting on a 2" by 2" square tube with a 1/4" thick top. The tube is tied into the back of the rear a-arm mount.
The passenger side is the same but I shortened up the stock mount a inch or so.
Had to cut away part of the cross member at the rear, about a inch off the top and a inch off the rear.
Shortened the battery tray and hacked off part of the passenger side.
The stock exhaust, cast header is going to be a issue down between the engine in the gas peddle area, but only about 1/2 "
I set the engine and transmission over about a 1/4" to the passenger side to help with the exhaust.
Cut the front pulley off the balancer so I could keep the engine farther forward.
My engine is a RB25DE and is normally aspirated, the RB25DET turbo engine gets a different trans. and would be the one to use as far as shifter position go's, but it is wider.
Time to build the trans. mount.

Bill Young was working on an mga with a 4.0, I think I maybe only ever saw one picture of it. But it seems like a good option for a straight 6!

Here is a look at what our Lumberjack had been working on:
[forum.britishv8.org]

Not a TR, but this shows what can be done with a modern drivetrain if one doesn't mind pretty much obliterating the original car.
[bringatrailer.com]

Oops, it's a V8.
Oh well.

Ivor