302 V8 Into a 1977 2500M?? --Help Please-

[shovel71]

I have a 1977 2500M that I use for Slalom and fast road use. Car presently has Triumph smogged motor (106HP with Strombergs!)which is now out of car as result of some tranny work required.

While apart, I am redoing suspension with poly, adj. Spax shocks, alloy rack mount, and cleaning up chassis to make the most out of the handling ability of the car.

Car is underpowered with smogged 2.5, and I was hoping to gain more HP but cost estimates I am getting are outrageous to get only about 150hp (don't want to lose driveability). Looking at engine options, and wondering if it is viable to look at a stock 302 5.0 instead of redoing the Triumph. I am in Cda so lots of 302 motors from Mustangs, parts easy/cheap to find, easy to work on, solid 200 hp stock, with stock reliability and a FIVE SPEED! Obviously need new mounts, rad ect,but have heard conflicting reports as to whether it fits in the late 2500/3000m chassis without major mods...can the stock Triumph rearend take 200 HP as would prefer not to change to Salisbury and the additional wt out back?

Anyone help with suggestions for the 302, or alternate ideas....any help greatly appreciated
Thanks in advance for any help given...
(PS...friend with a 78 3000m with blown Essex looking at same question?)
Shawn

[thegamekeeper]

Chassis will cope with no problem. Triumph TR6 diff will also handle 200bhp but make sure it is in 100% condition and preferably fit Quaiffe LSD internals in place of the weak planet gears

[SimonSparrow]

I'll be interested to hear how the conversion goes, good luck with it.

What is the weight differnce between the 302 V8 and the Triumph 2500 (or Ford V6) engine. Will this affect the handling?

[thegamekeeper]

The weight difference will probably be insignificant. Both the 2500 and the 3000 engines are incredibly heavy. The 302 has 5 litres worth of space in it in it. Also the V8 can be fitted much further back in the chassis compared to the very long Triumph unit

[Terminator]

I suggest you contact John Wadman in Ontario. He was the Canadian importer and distributor for TVR until a couple of years ago. They imported a number of M-series rolling bodies during the 1970s and fitted the 302 engine to make a TVR 5000M.

His email address is [e-mail]

[shovel71]

Thanks for the replys everyone! Am checking around now to see if anyone makes heavy duty TR-6 diff components for racing ect that may take the extra horsepower.....Have had conflicting reports of the wt of the Triumph motor, have been able to confirm that the 5.0 litre Ford is 460 with cast heads, and 430 with aluminum heads($$$), but have not been able to pin down wt of TR6 motor for sure...
Anyone help with spring/shock rates....not sure what stock spring rates are for the 2500m, have seen info here for 3000m but not sure if same??

Shawn

[davidy]

If you stay with the TR6 diff, beef up the diff carrier, this is a significant weak point in the drivetrain.

If you are going to do any race/sprint work with the car, ie hard standindg starts, I would recommend that you bin the TR6 diff and put in Salisbury, the main weak points on the TR6 diff are the TVR carrier and the TR6 diff front mounting plate, these take a lot of stress when doing fast starts (especially with modern grippy rubber), if you are going to be gentle off the line then you may get away with the TR6 diff.

davidy

PS I have broken two TR6 diff front plates and one TVR carrier (significant cracks) with just an Essex V6!!! before I saw the light and put a Salisbury in!

[alf]

Hi.
Quaife makes tr6 lsd for about 600£......
I have heard they are "almost unbreakable" from Steve Reid, he seems to know allot about this (also).

Alf

[shovel71]

Thanks all for the continued help....I will research the Quaiffe to see if I can find anyone in Cda that handles their limited slips as would like to stay with the TR6 diff if possible, and if it can handle the power...can think of a few ways to strengthen the carrier, but unsure of what "front" section you are referring to as weak? I do Slalom the car, but generally running starts so no heavy launches to speak of but obviously still considerably more power being driven through it with the on/off throttle...the Salsibury may prove to be required.
Shawn

[davidy]

The front section plate on the diff I was referring to is the mounting plate that the two big rubber bushes go in to mount the diff to the carrier. The carriers usually crack where the diff rubbers mount and crack outwards from the mounting bolts. If you ever look at a Salisbury carrier next to a TR6 carrier you will see that the TR6 carrier is a weedy affair. If you are going to stay with the TR6 diff, I would strengthen the carrier (thicken the metal) where the diff mounting bolts go and consider some significant triangualation to stop the whole thing twisting. I'm not sure that you can do much strengthening on the diff frontplate, but someone like Cambridge Motorsport in the UK may know the answer to that.

Basically with sticky modern rubber, on a quick getaway, the diff will try and twist in its mounting, if you have old sticky rubber the power will be lost in wheelspin, but sticky rubber will put significant additional stress on the diff/carrier/drivetrain.

Hope that helps

davidy

[shovel71]

Thanks..body comes off this weekend and will get a better look at the differential and plate you mentioned. Will assess it then and if Salisbury needs to go in, so be it....sourcing motor/tranny now.,..ought to be an interesting fall/winter....
Tks again for your help...
Shawn

[noahstvr]

The following components were installed in my 1973 2500. Motor 1986 5.0 HO,you want at least 85 for roller valve train. eldebrock RPM intake,holley 600 cfm 4 bbl, low profile air cleaner,fits with no power bulge in hood.1985 ford duraspark dist, only year with steel drive gear that goes with roller cam that doesent require eec control input.ford SVO usa sells a two wire wiring harness that uses the factory ignition module(duraspark),coil and dist.60's vintage cast iron hipo exhaust manifolds,installed to exit to the front, route exhaust parallel to oil pan. remote oil filter kit, dodge truck motor mounts,Nissan 620 pickup radiator, cheap,fits,inlets in correct position for ford motor.
T-5 trans. prefer from north american capri turbo,has close ratio gear set.fabricate remote shifter, its to far rearward to be practial.Find 3000M pedal asm.,uses cable as does the ford spec t-5 SVO sells cable.
Rear center section, C-4 corvette, fits carrier(subframe)with minor mod's, many ratio's,limited silp, and you won't BREAK it.good luck, Gary.

[Mickygee]

Forget the big heavy iron V8's and put in a nice Rover V8. Its light plus easy to get and MUCH cheaper to tune, works with a T5 or LT77 G'Box. And if you are running >220ft/1b torque I recommend you go for P'Lok salisbury (as cheap as going for Quaife internals). From a former Rover V8 M owner of 7 years.

[shovel71]

Question for Noahstvr....curious about the use of the C4 differential? Did you modify the C4 halfshafts or use the TVR stuff?

[braveheart]

V6 dry weight is 430lbs V8 is 460 lbs , definately go for this engine over a Rover as it can be made lighter with heads and intake,then your lighter than V6 and way ahead of the Rover in torque and horsepower and the bits are cheaper.

[SimonSparrow]

Is there a bellhousing to adapt the Rover or Ford V8 to the 4-speed Capri box in the 3000 M?

Would the box be suitable, I've heard its quite strong....

[davidy]

With the additional torque of a big V8 a five speeder is preferable, if you're going to the expense of a V8 then another gearbox is going to be no problem, and its just going to fit (clutch as well)

davidy

[Terminator]

If I was fitting a Ford V8 into an M-series, I'd go for a semi-auto sequential 5-speed.

But then, I'm getting old

[reynolj1]

My 1977 2500M was converted using a 1988 fuel injected Mustang GT 5L engine with T5 transmision. The fit is very good, only one frame tube was cut and then replaced (bolted with flanges). We changed to Ford mass-air-flow metering (from speed-density used in 1988), used older Mustang exhaust manifolds reversed (forward exits), moved shifter forward about 8 inches, and had exhaust fabricated (stainless, balance pipe, oxygen sensor). The car looks original; no bonnet problems, nothing odd in the interior, and the engine compartment is full but very clean and professional looking. I have the Salbury differential. I used 15 inch Panasport wheels with Z rated comp TAs. The car had dealer-installed air conditioning (!) so we connected the Ford AC compressor and the AC also works great. I used the stock springs with Spax shocks, feels OK, but I should adjust the ride height up a bit. There does not seem to be a major increase in weight from the conversion. Good luck with your project.

[danstanner]

I am using a late Lincoln MK8 dif in my conversion,the housing is aluminum with an 8.8 ring and pinion.