Lotus Excel V8 Conversion
Discussion
Soooo... recently aquired Excel. New interior, paint, wheels and tyres. Replaced a few odds and sods on the front suspension, tune up and off we go. Bit slowly really with only an alleged 180bhp.
These engines are really expensive to overhaul, so I thought "time for a V8" - of course. Only 5 V8's in the collection!
Now, a quick bit of history. Lotus were owned by Toyota in the 80's, so the parts bin yielded gearbox, diff, suspension etc for the Excel. A Supra gearbox and diff to be precise. So, the only way to go is with a Lexus V8 then. Conversion kit form Thailand, consisting of bellhousing, flywheel, clutch, fork, spigot etc. Great. Trigger wheel from Aus, as no one else does a 4" one. Engine mounts from Poland. Gaskets from the US. ECU from Dave Walker, Emerald.
Engine on its way out. Has to come out with gearbox.
Lexus Soarer for rear drop sump. New water pump and cambelt fitted. Valve safe too and 60K changes!
Gearbox removed, bellhousings swapped and test fitted. Left the flywheel etc off to reduce weight as the unit is going to be in and out a few times.
Engine mounts tacked in after 1st fit. Cross member modded for clearance, to be welded up. Ready for another check. Bit of a sod as you have to reconnect the prop every time as it is almost impossible to remove the prop without removing the diff first....
Back in again!
OE exhaust manifolds fit after removing the lower flange and a bit of fibreglass fettling.
So, not too bad for about 4 days work. Need to remake gearbox mount as it has parted company. Next step is to measure up for exhaust downpipes. Then engine and 'box out again. Finish welding mounts and paint. Run new return fuel lines and wire up ECU. Fit new alloy rad (Chinese, of course!), weld up exhaust manifolds, fit fuel pump,filter and reg. Make PAS pipes.
Oh, the plenum is a bit to high to clear the bonnet. Hmmm. Didn't want a bulge/scoop thing really.
Need to fit flywheel, clutch, starter etc. Next engine fit should be the last.
Got to hurry as I have another hospital visit next Friday.
These engines are really expensive to overhaul, so I thought "time for a V8" - of course. Only 5 V8's in the collection!
Now, a quick bit of history. Lotus were owned by Toyota in the 80's, so the parts bin yielded gearbox, diff, suspension etc for the Excel. A Supra gearbox and diff to be precise. So, the only way to go is with a Lexus V8 then. Conversion kit form Thailand, consisting of bellhousing, flywheel, clutch, fork, spigot etc. Great. Trigger wheel from Aus, as no one else does a 4" one. Engine mounts from Poland. Gaskets from the US. ECU from Dave Walker, Emerald.
Engine on its way out. Has to come out with gearbox.
Lexus Soarer for rear drop sump. New water pump and cambelt fitted. Valve safe too and 60K changes!
Gearbox removed, bellhousings swapped and test fitted. Left the flywheel etc off to reduce weight as the unit is going to be in and out a few times.
Engine mounts tacked in after 1st fit. Cross member modded for clearance, to be welded up. Ready for another check. Bit of a sod as you have to reconnect the prop every time as it is almost impossible to remove the prop without removing the diff first....
Back in again!
OE exhaust manifolds fit after removing the lower flange and a bit of fibreglass fettling.
So, not too bad for about 4 days work. Need to remake gearbox mount as it has parted company. Next step is to measure up for exhaust downpipes. Then engine and 'box out again. Finish welding mounts and paint. Run new return fuel lines and wire up ECU. Fit new alloy rad (Chinese, of course!), weld up exhaust manifolds, fit fuel pump,filter and reg. Make PAS pipes.
Oh, the plenum is a bit to high to clear the bonnet. Hmmm. Didn't want a bulge/scoop thing really.
Need to fit flywheel, clutch, starter etc. Next engine fit should be the last.
Got to hurry as I have another hospital visit next Friday.
V8 FOU said:
Soooo... recently aquired Excel.
So, not too bad for about 4 days work.
.
You're not messing about are you. I do love a retro car with a modern engine so i'l be checking in on this thread.So, not too bad for about 4 days work.
.
How will the supra gearbox set up and original diff ratio be with the V8/? I've seen a few v8 Soarers with manual swaps and they seem to shift, your Excel ought to be the best part of 400Kg lighter so it's going to pack quite a punch!!!!
Thank you gentlemen!
This has a certain logic about it. Lotus use Toyota engines exclusively now, so this is a "natural" choice.
The engine is only around 50kg heavier. The total weight of the car will be sub 1200kg, and the power near to 300bhp. So getting near that magic 300bhp/ton. These engines have a flat torque curve from 1000 rpm.
The present diff is 4.1 :1 and open. I will probably fit a 3.9 lsd from a Supra Turbo. The W58 gearbox will be a bit near its limit, so some high quality oil will be needed and after testing possibly a cooler.
I'll keep you updated!
This has a certain logic about it. Lotus use Toyota engines exclusively now, so this is a "natural" choice.
The engine is only around 50kg heavier. The total weight of the car will be sub 1200kg, and the power near to 300bhp. So getting near that magic 300bhp/ton. These engines have a flat torque curve from 1000 rpm.
The present diff is 4.1 :1 and open. I will probably fit a 3.9 lsd from a Supra Turbo. The W58 gearbox will be a bit near its limit, so some high quality oil will be needed and after testing possibly a cooler.
I'll keep you updated!
A while back I was reading about Excels and read that the gearbox was Toyota. First thought was I wonder how hard it would be to fit a Lexus V8. Nice to see someone doing it!
I think that this could be an ideal car - four seats, hoofing great V8 and excellent chassis. Good luck with the build!
I think that this could be an ideal car - four seats, hoofing great V8 and excellent chassis. Good luck with the build!
So, progress has been a little slow due to the eye job in hospital, plus real work interfering with the proper jobs!
Knackered gearbox mount. Very expensive from Lotus, so decided to make a polybush one.
Got the correct 4" trigger wheel from Aus, as they were the only ones to do the 4". Only problem was that it is flat and needs a dish, So I used the old one to make a spacer.
Trigger wheel and spacer fitted
Fitting the covers etc. Note the blanking plate over the old hydraulic fan pump.
Gearbox back on with flywheel, clutch etc fitted.
Holes drilled and tapped m4 for the coil pack bracket
Top bracket fitted with Ford type coil packs.
Blanking plate in plenum where the cold start injector went.
New alloy (Chinese) rad. May fit new fans. Need to order hoses etc.
Still have to run wiring through with return fuel pipe, and install swirl pot and pressure pum, etc, etc....
All a bit slow, but hope to be somwhere near running by next weekend.
Knackered gearbox mount. Very expensive from Lotus, so decided to make a polybush one.
Got the correct 4" trigger wheel from Aus, as they were the only ones to do the 4". Only problem was that it is flat and needs a dish, So I used the old one to make a spacer.
Trigger wheel and spacer fitted
Fitting the covers etc. Note the blanking plate over the old hydraulic fan pump.
Gearbox back on with flywheel, clutch etc fitted.
Holes drilled and tapped m4 for the coil pack bracket
Top bracket fitted with Ford type coil packs.
Blanking plate in plenum where the cold start injector went.
New alloy (Chinese) rad. May fit new fans. Need to order hoses etc.
Still have to run wiring through with return fuel pipe, and install swirl pot and pressure pum, etc, etc....
All a bit slow, but hope to be somwhere near running by next weekend.
More progress - pics to follow.
Modified stock exhaust manifolds to fit, welded up some pipe/elbows courtesy of Jetex. Now got as far as the X pipe. Should all be more or less there tomorrow. Return fuel line fitted, clutch slave fitted and bled. Jeez, that's heavy, so gonna need a servo!
The swirl pot and pumps also should be finished tomorrow. Managed to get a proper diverter heater valve, as these engines are designed to have the water flowing thru' the heater matrix and control the temp with air blend.
I have been Ebaying with some gusto! Ordered hose and fittings for the PAS. And the crimpy things for the ends. 2 banjos and bolts for the fuel rail. Oil pressure gauge and light T piece. Universal throttle cable. Elbow and fittings for the fuel pump.
Hoses and joiners for the radiator.
I shall upload some pics asap.
Modified stock exhaust manifolds to fit, welded up some pipe/elbows courtesy of Jetex. Now got as far as the X pipe. Should all be more or less there tomorrow. Return fuel line fitted, clutch slave fitted and bled. Jeez, that's heavy, so gonna need a servo!
The swirl pot and pumps also should be finished tomorrow. Managed to get a proper diverter heater valve, as these engines are designed to have the water flowing thru' the heater matrix and control the temp with air blend.
I have been Ebaying with some gusto! Ordered hose and fittings for the PAS. And the crimpy things for the ends. 2 banjos and bolts for the fuel rail. Oil pressure gauge and light T piece. Universal throttle cable. Elbow and fittings for the fuel pump.
Hoses and joiners for the radiator.
I shall upload some pics asap.
Great project, seems to make good sence as a swap. I've always loved the exotic looks of the '80's Excel and Esprit but it's hard to not to feel that they are a bit under-engined with the 4 pot, particularly by modern standards. A V6 or V8 gives the kind of performance and sound that the cars look like they should have.
opcorn:
Time for an update......
Swirl pot / pressure pump etc mounted on a board, readt to fit.
Exhaust manifolds adapted and painted
And wrapped.
Inter X pipe made/painted/wrapped. Rear original silencers adapted - hope they aren't too quiet!
Clutch servo and air horns installed in the nose
Hole cut to access the throttle cable - almost impossible from inside!
Diverter heater valve. Needed as this engine is designed to have the heater circuit on continuously open, whereas the car normally uses an on/off valve. This one, obtained from Dax Cars, acts as a diverter. Had to cut and shut the mechanism as it operated the wrong way for the control cable.
ECU wiring started. Also showing the plug lead cover I made.
Wiring loom for injectors under construction.....
Decided to fit new compact fans to the new radiator.
This does skim over the surface a bit. Loads of other stuff done. Made up PAS hoses, installed new front-rear fuel pipe, installed clean earth and fuel pump feed (battery in boot), exhaust system now fitted, using the original rear silencers, starter and alternator wired, tachometer, temp gauge, oil gauge etc wired.
Fitted main / fuel / fan relays today and fuse box. Had to re position the coils (again) as they were too near the throttle body. Should have the new plug wires from Magnecor this week. So it might even be running by the weekend. Possibly.
Swirl pot / pressure pump etc mounted on a board, readt to fit.
Exhaust manifolds adapted and painted
And wrapped.
Inter X pipe made/painted/wrapped. Rear original silencers adapted - hope they aren't too quiet!
Clutch servo and air horns installed in the nose
Hole cut to access the throttle cable - almost impossible from inside!
Diverter heater valve. Needed as this engine is designed to have the heater circuit on continuously open, whereas the car normally uses an on/off valve. This one, obtained from Dax Cars, acts as a diverter. Had to cut and shut the mechanism as it operated the wrong way for the control cable.
ECU wiring started. Also showing the plug lead cover I made.
Wiring loom for injectors under construction.....
Decided to fit new compact fans to the new radiator.
This does skim over the surface a bit. Loads of other stuff done. Made up PAS hoses, installed new front-rear fuel pipe, installed clean earth and fuel pump feed (battery in boot), exhaust system now fitted, using the original rear silencers, starter and alternator wired, tachometer, temp gauge, oil gauge etc wired.
Fitted main / fuel / fan relays today and fuse box. Had to re position the coils (again) as they were too near the throttle body. Should have the new plug wires from Magnecor this week. So it might even be running by the weekend. Possibly.
More progress. Gawd, this is a long job.
Magnecor leads showed up. Real bit of stress as there is always that "I hope I got these right" as this is a (expensive) custom set.
No worries. Fitted beautifully.
Header tank going in. Note relays and fuses box for all the new things. The coils and injectors on one fuse, ecu on another, radiator fans on another. The rad fans are, in fact, controlled by the ecu. There is a clean earth lead for the ecu going all the way back to the battery to stop any possible rfi problems. I have even earthed the screening for the crank sensor for the same reason. Coils are standard Ford types as I am running wasted spark.
Radiator in with new fans and hoses. Should be able to vac out the cooling system to test it tomorrow.
Alternator and PAS pump in and connected.
Seriously expensive gearbox lube. 2 of these needed. About £30 the two! But, seeing as the gearbox is going to be getting the surprise of its life, it needs all the help it can get. I will monitor the temp of the gearbox once it is being used / ragged etc. If it gets too hot, I will cool it. Just pump the oil out from the drain plug and back in again usually does the trick.
Magnecor leads showed up. Real bit of stress as there is always that "I hope I got these right" as this is a (expensive) custom set.
No worries. Fitted beautifully.
Header tank going in. Note relays and fuses box for all the new things. The coils and injectors on one fuse, ecu on another, radiator fans on another. The rad fans are, in fact, controlled by the ecu. There is a clean earth lead for the ecu going all the way back to the battery to stop any possible rfi problems. I have even earthed the screening for the crank sensor for the same reason. Coils are standard Ford types as I am running wasted spark.
Radiator in with new fans and hoses. Should be able to vac out the cooling system to test it tomorrow.
Alternator and PAS pump in and connected.
Seriously expensive gearbox lube. 2 of these needed. About £30 the two! But, seeing as the gearbox is going to be getting the surprise of its life, it needs all the help it can get. I will monitor the temp of the gearbox once it is being used / ragged etc. If it gets too hot, I will cool it. Just pump the oil out from the drain plug and back in again usually does the trick.
Edited by V8 FOU on Wednesday 15th February 19:44
Well, it's going!
Bit of a task really. Lots of pipework and wiring.
Had a bit of trouble getting it to start - reversing the crank sensor wires did the trick. When all else fails, read the instructions, again.
I have to say that Karl and John at Emerald have been brilliant. John spent 20 mins on Team Viewer sorting it out. I've done a bit of further tweaking to the map.
Did the first road test this evening. First gear now totally redundant - in fact, around the town it can be left in 4th most of the time, pulls from under 1000 rpm ok! Torque is most impressive. It should improve with the adaptive mapping from the wideband lambda. Very interesting that the poly engine/gearbox mounts don't make for a lot of harshness.
Had a problem with the clutch not engaging properly, the master cylinder push rod was too long so didn't have any free play. Cut some extra thread and job done. It could do with a larger slave cylinder as there is too much throw, very light clutch action with the 3:1 servo doing its stuff. It is running a little hot, but the thermostat is in the bottom hose connector. So I will drill a hole in the thermostat to drop the temp a little. That fancy heater valve was a waste of money - no circulation so I fitted the original valve and cured that.
The exhaust is a bit quiet, so need to address that. Also need to mod the plenum so I can get the bonnet to shut properly. Or fit some throttle bodies......
It is an interesting engine. Not like any other V8 ( I have, errr, about 5 ) - sounds good even with the quiet exhaust. I will get it fully mapped when I decide whether I will fit throttle bodies or not.
Worthwhile conversion? You bet. Still only 1200kg or so and I guess around 300bhp. A very long job. I have been on it for about 2 months! With the extra development work it should be a pretty amazing car.
I will post some more pics soon.....
Bit of a task really. Lots of pipework and wiring.
Had a bit of trouble getting it to start - reversing the crank sensor wires did the trick. When all else fails, read the instructions, again.
I have to say that Karl and John at Emerald have been brilliant. John spent 20 mins on Team Viewer sorting it out. I've done a bit of further tweaking to the map.
Did the first road test this evening. First gear now totally redundant - in fact, around the town it can be left in 4th most of the time, pulls from under 1000 rpm ok! Torque is most impressive. It should improve with the adaptive mapping from the wideband lambda. Very interesting that the poly engine/gearbox mounts don't make for a lot of harshness.
Had a problem with the clutch not engaging properly, the master cylinder push rod was too long so didn't have any free play. Cut some extra thread and job done. It could do with a larger slave cylinder as there is too much throw, very light clutch action with the 3:1 servo doing its stuff. It is running a little hot, but the thermostat is in the bottom hose connector. So I will drill a hole in the thermostat to drop the temp a little. That fancy heater valve was a waste of money - no circulation so I fitted the original valve and cured that.
The exhaust is a bit quiet, so need to address that. Also need to mod the plenum so I can get the bonnet to shut properly. Or fit some throttle bodies......
It is an interesting engine. Not like any other V8 ( I have, errr, about 5 ) - sounds good even with the quiet exhaust. I will get it fully mapped when I decide whether I will fit throttle bodies or not.
Worthwhile conversion? You bet. Still only 1200kg or so and I guess around 300bhp. A very long job. I have been on it for about 2 months! With the extra development work it should be a pretty amazing car.
I will post some more pics soon.....
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