Jump to content

TR7 Engine Into A Spitfire


dazasdolly

Recommended Posts

I did a sprintfire into a mk3 22 or so years ago.
So as Steve says, a TR7 lump would be OK too. Not easy though.

Now I shall don my tin hat.
Unless there is a compelling reason to fit the TR7 engine, there are better swaps available. And in real cash terms costs are similar. Cheapest has to be MX5 running gear, though like the slant 4 exhaust is a tad tricky.

Link to comment
Share on other sites

As Clive says, it has been done before (or at least the Sprint conversion has), but why would you.

The TR7 or even Sprint engine is not that great by modern standards.  Heavy, not especially powerful, not especially reliable and hard to fit, particularly if you want to avoid chopping the car about.  Even the Triumph straight six weighs only a little more could be just a powerful as the Sprint lump and is much easier to fit as all the parts to do so exist.

Much I like the Triumph 6 though, I'd still be looking at something more modern, one of the Ford Zetecs (the SE Sigma version probably due to light weight) or the MX5 which conveniently comes with a nice 5 speed box attached.

Nick

Link to comment
Share on other sites

Quoted from cliftyhanger
Cheapest has to be MX5 running gear, though like the slant 4 exhaust is a tad tricky.


Depends... Mine worked out cheaper than most because I'm in a position to not have to pay to get things fabricated. I also got a very cheap car with the perkiest MX5 engine I've ever tried because it was being sold with a terrible advert and I took a punt without seeing or trying it first. Depending on how you go about it (buying a car or unknown engine and gearbox, and ecu, and other bits...) I think it'd work out only marginally cheaper to a Ford engine. And a lot cheaper than trying to get similar performance from a Triumph engine.

The exhaust can be done easily. Seth had room to lobster-back his and get it between the gearbox and chassis. I have my engine fitted further back and lower, so even the slave for the clutch misses the chassis by mm. If you make your own manifold or get one made it's fine. For the turbo I'm going for a simple log manifold and that will solve all exhaust routing issues for me.

The more I tinker and get the car tweaked the happier I get about going away from Triumph engines. Last week I changed the fuel system and now it's got as much get up and go when fully loaded with tools, a passenger and the longer diff as it used to when the boot was empty, I was on my own and a 4.11. The longer diff also lets me go from 2nd gear to 5th at 60mph.

Link to comment
Share on other sites

Trust me, if you have to pay somebody to do any of these conversions it would be cheaper to buy a decent cayman.
MX5 cheapest as it is single donor, probably the only one? All others require stuff from a few cars. And it is always the odd bits that really cost.

Triumph OD boxes being a case in point, with a TR7 engine it really needs a sprint gearbox, or poss LT77 from the TR7 (presume it will go in OK) so a rusty TR7 donor could make it viable? Economical engine too.

Link to comment
Share on other sites

Thank you for the replies, I only asked as there are a lot of TR7 engines about and all seem to be very cheap.

MX5 option could be a good option as I have a friend who is a mechanic and he may have the engine etc available from a parts car very soon (will keep you updated).

Is there much info on this conversion.

Many thanks again

Darren

Link to comment
Share on other sites

If anyone wants a Zetec a friend of mine is selling a 1.25L Zetec engine from a low mileage Fiesta. Car had a minor front ender (bumper, grille, lights and rad, but nothing more), but being a mid-nineties Fiesta it was more economical to break the car and buy another one than repair what he had.

Link to comment
Share on other sites

I think any of the 1.6 or 1.8. But do your research. Some early UK 1.6's and many imports are 115bhp and pretty perky, later ones were detuned o 90bhp (I think in he uk when they brought out the 1.8, but check carefully)
The 1.8 are approx 130-140bhp.

Get everything you can. You want at least the COMPLETE engine and gearbox. The wiring loom/fusebox, I would suggest the whole thing if possible. Matching ECU. Ferny used the clocks too in a bespoke dash. You may need a key as well if later cars had transponders (this can be permanently attached to the ecu so you carry on with your original Triumph ignition lock) Prop may be useful.

In all honesty I would buy a complete car, they are cheap enough if rusty. Sell off a few bits and get most of your money back and then you will have everything you may need.

Do some research on the kitcar forums. Using the mx5 as a base is very popular nowdays, for good reason. The engines are pretty bombproof and they are cheap.

Link to comment
Share on other sites

I only really know anything about the NA (1.6) and NB (1. variants. You can tell the difference from the position of the coil pack and the 1.6 lettering on the cam cover is recessed and on the 1.8 it's raised. They aren't interchangeable as the 1.8 unit is around an inch longer.

Be careful with early 1.6 engines and try to get a long nose with 8 slots in its pulley as the short version (4 slots) has been know to wear its key-way which puts your timing out and eventually turns the crankshaft to scrap. As said, later 1.6 were reduced to 90bhp and aren't sought after. For the same reason the automatic engines (90bhp) aren't wanted. It's not as simple as changing the camshaft to get the power back either.

I doubt you'll happily fit a 1.8 in without bulkhead tweaking. For my 1.6 transplant I moved an area of the bulkhead back by over an inch and it's given me just enough room. Others haven't needed to do this but it means their engine sits further forward and higher - my pulley is right over the steering rack. Having it further forward makes the exhaust and gearbox choices easier. The 1.8 would leave you even less room for a radiator and if you use the original intake system space is tight. If the 1.6 is used and the bulkhead not changed you can use the Triumph heater.

Two schools of thought over 1.6 or 1.8. Some say the bigger has more torque, some same the smaller revs better and is happier to receive a turbo. Objective people seem to say you don't notice a great deal of difference as the extra weight of the 1.8 evens everything out.

Any Mazda gearbox will fit (I believe this includes the RX7 and RX8, but check). So you have a choice between the 5 and 6 speeds. Final drive is the same. Depending on how you fit the engine and where you sit you may need to shorten the gearbox select. I cut 7" out of mine and had to take a lot (I mean a lot) of the casting away to both get the stick where I wanted and to physically fit the unit. The handbrake also needed moving. Others haven't needed to.

Either go straight to Megasquirt (plug and play systems are available off the shelf), use the Me221 (new unit and again plug and play), use the original or get creative. None of those options are as simple as you'd expect as although you can use the original loom, you won't be able to use it without changing it. My wiring took a four weeks of mostly weekends and the odd evening. I also used the original fuse boxes and added my own which are mounted where the battery would normally fit and the battery is in the boot. I use the original Mazda key. In the Mazda one fuse box sits by the drivers knee, one sits in the engine bay in front of the driver and most wires run into the cabin on that side. Don't underestimate the complications of modifying a loom (stripping away what you don't need and either shortening or lengthening everything you do) over creating one from scratch for another type of engine transplant. I needed to refer to five wiring diagrams, all had errors which didn't match my car and two were in Japanese.

I use the Mazda propshaft, others have used a modified Triumph one. The propshaft is too short and either requires a spacer or a new one being made from scratch. Length is dictated by how you fit the unit as a whole.

Exhaust creations won't be able to be realised until it is in either.

Fuel system requires research and personal choices.

Some links and photos for you;

http://www.miata.net/garage/compatibility.html

http://www.miata.net/garage/crankshaft.html

http://www.miata.net/garage/

http://www.solomiata.com/Mx5Engine.html

I have many PDF's if you need them.













Link to comment
Share on other sites

Hi,

Great work Ferny, must have a closer look if I see you driving round Sundon Park.

Took a picture of a Sprint engine in a Spitfire a few years ago at Retro Show up The Pod -



I see a lot of K series engines fitted to Midgets, anyone fitted one of these, light and readily available plus a turbo version available ???


Cheers John

Link to comment
Share on other sites

Quoted from john 215
Hi,

Great work Ferny, must have a closer look if I see you driving round Sundon Park.

Took a picture of a Sprint engine in a Spitfire a few years ago at Retro Show up The Pod -



I see a lot of K series engines fitted to Midgets, anyone fitted one of these, light and readily available plus a turbo version available ???


Cheers John

Feel free, but I'll warn you it looks better in the dark!

I think that Spitfire belonged to Mr Speedy.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...