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.
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!
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.
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.....
crofty1984 said:
Bloody hell. I've been working on my excel for 5 years and it's still not on the road!
Good going.
What are you doing with the old engine? Mine's only the lc version.
I still have the engine if you are interested. It seems to be a cross over between an lc and hc. I have plenty of other bits left over. Front brakes, lightweight flywheel etc. pm if you are interested!Good going.
What are you doing with the old engine? Mine's only the lc version.
Gave it a bit of welly last night. The adaptive control seems to be working well. You can pull away in 2nd, and pull from 800rpm in 4th!
More soon......
^^^ WTF?
Anyway, a few pics as promised.
Full Frontal (!) showing temp cone filter, now with IAT sensor and IAC valve plumbed in. Ipework a bit odd, as the t/stat is in the bottom hose.
Each side of the engine bay. You can just see in the lower pic, the new washer tubing. Had to fit one of those scrotal washer bags as the ECU and header tank are living in the place where the old one was. I'm so pleased with the HT lead covers. Look almost original!
The plenum and throttle body need to be lowered or the bonnet altered so the bonnet will close.Fitted the under tray and the coolant temp has dropped 5deg +.
Had a go at the exhausts as the original rear silencers seemed to be strangling the motor. Converted them to absortion types. Wow! What a difference - sounds like a Maserati. Performance has improved too. Suppose 2 silencers designed for a 2.2lt engine can't cope with 4lt of V8......
Above shows the bonnet strut after it had been cut and shut. This braces the bonnet - but it was rubbing on the top hose. So, cut, fabricate and weld. As ever.
Gave the car a bit of a ragging this evening, and the sound if nothing else, is brilliant!
Future plans may include fitting these BMW throttle bodies with fly-by-wire to give mappable throttle. The Emerald ECU has the capability to do this. Not to mention flat shift. Oooh lots more fun to come!
Anyway, a few pics as promised.
Full Frontal (!) showing temp cone filter, now with IAT sensor and IAC valve plumbed in. Ipework a bit odd, as the t/stat is in the bottom hose.
Each side of the engine bay. You can just see in the lower pic, the new washer tubing. Had to fit one of those scrotal washer bags as the ECU and header tank are living in the place where the old one was. I'm so pleased with the HT lead covers. Look almost original!
The plenum and throttle body need to be lowered or the bonnet altered so the bonnet will close.Fitted the under tray and the coolant temp has dropped 5deg +.
Had a go at the exhausts as the original rear silencers seemed to be strangling the motor. Converted them to absortion types. Wow! What a difference - sounds like a Maserati. Performance has improved too. Suppose 2 silencers designed for a 2.2lt engine can't cope with 4lt of V8......
Above shows the bonnet strut after it had been cut and shut. This braces the bonnet - but it was rubbing on the top hose. So, cut, fabricate and weld. As ever.
Gave the car a bit of a ragging this evening, and the sound if nothing else, is brilliant!
Future plans may include fitting these BMW throttle bodies with fly-by-wire to give mappable throttle. The Emerald ECU has the capability to do this. Not to mention flat shift. Oooh lots more fun to come!
Edited by V8 FOU on Tuesday 28th February 19:33
Well, more progress. Bonnet has had to be cut around to fit. You've heard of "BIW" body in white? Well this is "BIP" Bonnet in pug....
Note the splits in the gel coat to make the panel curve.
Now for a little automotive porn.....
and again
Those brakes are sooooo good. Had to make up some braided flexi pipes, otherwise fittimg was a p o p. Managed to damage a wheel and tyre in a pothole. So I have fitted some tyres I had left over from the Bentley. Now 255/45 .17 instead of 215/40.17 That has raised the gearing a bit! Looking to change the diff - bought the wrong one for a Supra MA70 instead of a MA60. So may try and fit the ring gears to the original housing.
Done about 1000 miles in it now and it is great. About 23mpg too. I'm pretty pleased so far. Next step is to get a dyno run to check the power output so I can decide where to go with the power. Need some decent shox too.
Just love driving it. A Lotus with gobs of power and upgraded brakes. Still loads to do. Keep tuned. (Did I really say that?)
Note the splits in the gel coat to make the panel curve.
Now for a little automotive porn.....
and again
Those brakes are sooooo good. Had to make up some braided flexi pipes, otherwise fittimg was a p o p. Managed to damage a wheel and tyre in a pothole. So I have fitted some tyres I had left over from the Bentley. Now 255/45 .17 instead of 215/40.17 That has raised the gearing a bit! Looking to change the diff - bought the wrong one for a Supra MA70 instead of a MA60. So may try and fit the ring gears to the original housing.
Done about 1000 miles in it now and it is great. About 23mpg too. I'm pretty pleased so far. Next step is to get a dyno run to check the power output so I can decide where to go with the power. Need some decent shox too.
Just love driving it. A Lotus with gobs of power and upgraded brakes. Still loads to do. Keep tuned. (Did I really say that?)
The Crack Fox said:
Paul - great thread!
Did you buy this car from Allon White Ltd, or a Brit who was living in the US who left it with them years ago? They had a low mileage car with electrical issues in their yard in the same colour, with the same wheels, for ages. I nearly bought it but it had sold when I finally tracked down the owner! It has a carbon fibre dash, smoked rear lights and the shall is deseamed. Same car, perchance?
Good luck!
That's the one! Seems everyone was thinking of buying it. Managed to remove all the stick on CF, now going to remove the rest and make the inside a bit more subtle.Did you buy this car from Allon White Ltd, or a Brit who was living in the US who left it with them years ago? They had a low mileage car with electrical issues in their yard in the same colour, with the same wheels, for ages. I nearly bought it but it had sold when I finally tracked down the owner! It has a carbon fibre dash, smoked rear lights and the shall is deseamed. Same car, perchance?
Good luck!
Orft tomorrow to get a dyno run to see how many horses there are. Then I can decide if I need more...... as if.
Thanks for the comments.
Had to fit a new speedo cable today, so while it was in the workshop I thought i would put it on the corner weight scales.
1150kg - the same as stock!! Shows how heavy that awful slant four is......
Reckon I could easily get 80kg out with a litium battery, remove back seats and lighter front seats. Oh, that boot spoiler must weigh 10kg+!
Funny, the weight is the same as my Alfa147 TS!!
Had to fit a new speedo cable today, so while it was in the workshop I thought i would put it on the corner weight scales.
1150kg - the same as stock!! Shows how heavy that awful slant four is......
Reckon I could easily get 80kg out with a litium battery, remove back seats and lighter front seats. Oh, that boot spoiler must weigh 10kg+!
Funny, the weight is the same as my Alfa147 TS!!
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