BiTurbo228

Old(ish) thread, but I've got nascent plans to do just this. I've amassed 4 PE166s from cheap eBay finds so hopefully I should be ok on parts availability, and I've got some measurements. People assume that being an OHC engine the 2600 must be taller than the OHC, and it is but really not by much. It's ~21" (closer to 20.5") from the shallow end of the sump to the top of the cam cover, compared to 20" for the OHC. As far as I can tell the difference is made up by having a bit of a shorter block (the stroke's a more reasonable 84mm compared to 95mm for the OHC 2.5l) and the Triumph engine not actually having all that compact of a rocker arrangement. Its main issue for wedging into a Spitfire is that it's definitely longer. For an I6 the Triumph engine is very short so that's going to be hard to beat. The 2600 is 28.25" long from the gearbox mounting face to the crank pulley, which doesn't seem that bad compared to 27" for the OHC, but the Rover cam cover continues at full height practically all the way to the front of the block (27.25") whereas the OHC rocker cover stops a good way back and then drops down slightly to the thermostat housing. It's the same story at the back, where there's a good inch and a bit between the back of the OHV head and the gearbox face, whereas the Rover engine is practically flush. I suspect this is why the big saloons needed bonnet bulges. Because of the angle the T2000 engine is mounted at that extra length would push the nose of the engine much further up. If it could be mounted a little more level (not amazingly difficult) then I suspect it'd fit in a big saloon just fine. Maybe with a Mk1 bonnet at most. Spitfires are a little trickier. There really isn't much space above the rack, and the nose of the engine is already pretty close to the bonnet bulge. I've already moved my OHV engine back a good 3" to drop the engine down so the rack just clears the bowl of the sump (it sits just above the flange at the front). To get the Rover engine to the same position I'd need to move the gearbox back another 4.25" which would make bellhousing clearance very difficult (as it is I've needed to clearance a fair bit to get the Saloon OD 'box to fit). So the plan is to drop it back as far as I can then adjust the oil pickup pipe which is the main issue with sump clearance. You can see it in this drawing (with the measurements I've taken) See it drops down approaching the front to get a decent bend radius into the nose-mounted pump? That's what drops the front of the sump down to make it 21" tall. The side without the oil pickup pipe is 20", and that could easily be made shorter. The plan is to continue hugging the block a little further forwards/oval the pipe/tuck it up into the block to create a little clearance hump in the sump to sneak the rack through. I'll have to see how it goes with crank clearance, but that's the current plan! tl;dr they're surprisingly compact for an OHC I6, but not quite compact enough to make it an easy swap. Oh, and I measured the camshaft and it's definitely detuned. Needly little bumpstick. Cutting 1mm off the base circle diameter would sort that out nicely. End up with a cam just a little hotter than an M20B25 K-cam.

It's less that I don't want the power bulge (I actually rather like how it looks), more that I'm trying to figure out the effect of moving weight behind the front axle. It's a bit late to be changing things on my current Spit6 project, but it'd be useful info to know for future reference (and comparison as I'm trying to get the same weight distribution using lightweight parts rather than moving the engine). Yeah that's it Now that's interesting. I didn't know they'd raised the engine as well. No wonder the Spitfire and the GT6 placed poles apart in this handling test: http://michaeljay.tripod.com/spitfires/cdtest/ Distribution's one story, but CoG height and moment of inertia are another...

Hi there, New to this forum, but an active member over at Club Triumph. I've been trying to find out what effect on the weight distribution moving a 6-cylinder backwards in the chassis has on a GT6 or Spitfire. I've heard at least one person here's done that to avoid fitting a bonnet bulge, and I was wondering if anyone's measured the distribution. Thanks Simon