turbo-charging Lotus?

I would like to turbo-charge my 1972 Jensen- Healey with an all aluminum Vauxhall based Lotus 16V dohc/dual carb (weber progressives in my case). Any ideas?

I guess this post is long dead but for the record Lotus has always maintained that the Jensen Healey’s 907 engine is not Vauxhall based. That misconception started because an early development mule used by Lotus for the 907 heads used a Vauxhall block before the 907 block was delivered.

In response to the question it’s certainly feasible. One should keep in mind that Lotus themselves created turbo versions of the 9XX series. They are very highly evolved compared to the early Jensen Healey motors. It would be a very extensive (and expensive) project.

PC.

The Jensen Healy Preservation Society is selling cast iron Vauxhall crankshafts to stroke 907 engines., so perhaps Lotus doth protest too much.

Early Turbo Esprits blew through Delorttos, maybe that stuff could be adapted? Sports Cas World in Texas parts out a lot of Loti, they might have Lotus parts if you can determine that they fit.

The Engine bay in an Esprit is very, very different from that of a Jensen Healey. I would suspect that few of the external parts would fit. The internals of an early 907 from a JH are not up to the task either.

These days turbo motors and suppliers are common enough that I would likey skip the Lotus parts entirely and go with a custom or semi-custom turbo setup with fuel injection.

The internal mods for a high output 907 are fairly well known. For a blown motor I would build it up much like a stage 3 or 4 race engine but with lower compression and application specific cams.

Anyway, as I said it would be a very extensive (and expensive) project.


PC.

I've recently restored a '74 Jensen Healey and completely built up the engine with the stroker crank (2.2) light pistons, Delorttos, and aluminum flywheel. As interesting as a turbo may be, I don't know how/where you could possibly route the plumbing to the intake. As it is the headers are VERY close to the frame rail and the steering shaft goes between the tubes.

Rather than turbo you might go with a crank driven supercharger. One of the centrifigual ones would operate like the turbo but without the lag. I do agree that you will need a stronger set of internals to pull this off. Or keep your stock motor, and see what you can shoehorn in that already has turbo, injection and all. I would suggest the 4 out of an old Escort EXP. They were cheap and plentiful, and there is some relatively good support through the Ford Escort Owners Assn. Then your Lotus engine would be safe if you ever wanted to go back for a restoration or something. But if you boost it, one way or the other there won't be much left of it for long.

MattP

Matt has a wise suggestion, and one that would prove cheaper in the long run too.

I believe the EXP motor puts out less power than the Lotus so swapping one in would still mean a lot of modifications will be needed for any net benefit. On top of that there would always be the stigma of being the guy that removed Lotus aluminum and replaced it with Ford iron (not a pretty reputation).

The mechanical supercharger concept has merit. Whether positive displacement or centrifugal the bottom line is that you don’t have to plumb the exhaust so the installation would be simpler. I’ve seen pictures of a JH with what appears to be a rootes blower but I don’t know any of the details.

If the car is stock you might be surprised at how much improvement you get with standard mods like carbs and cams.


PC.

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by PC:
I believe the EXP motor puts out less power than the Lotus so swapping one in would still mean a lot of modifications will be needed for any net benefit. On top of that there would always be the stigma of being the guy that removed Lotus aluminum and replaced it with Ford iron (not a pretty reputation).

The mechanical supercharger concept has merit. Whether positive displacement or centrifugal the bottom line is that you don’t have to plumb the exhaust so the installation would be simpler. I’ve seen pictures of a JH with what appears to be a rootes blower but I don’t know any of the details.

If the car is stock you might be surprised at how much improvement you get with standard mods like carbs and cams.


PC.<hr></blockquote>

The EXP was just the first and cheapest thought. I would first suggest finding the most power that would fit, and work from there(heck you might even look at a v-6 or v8.

But I do agree that a super or turbo charger are for after the other mods have been thouroughly researched and/or tried. In the dollar to bang ratio, sometimes they aren't the best option. For instance, and NOS system would definately be cheaper, and easier to apply.

MattP

I happen to have a set of brand new Delorrto 45's, already jetted for a 907, along with the manifold (used), soft mounts (new), and air horns (new). I've got a set of European Lotus Elite cams, too. This stuff should get you up to 160 horses or so.

Now wait a minute.. Didn't you start out by saying you wanted the Vauxhall 16V DOHC with Webers, or Del'orto's?

This would be the screaming way to go unblown..Lot's of parts and go fast stuff for those motors.. They would be my number one choice for an off shore motor swap from England,

Or if you want blown power how about a Cosworth YB 2.0 16V? Those are found in the Ford Sierra and Escort Cosworth's.. and you can get kits to convert them to carbs as well..

The Zetec E motors are popular as well as good looking, but ultimately you'll get about only 165 hp out of the two liter with bolt on stuff..

Lot's of cool stuff available but don't forget the Rover V8 is a very easy swap into your car as well... And you could find one without going off shore..

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by TypeRboy:
Now wait a minute.. Didn't you start out by saying you wanted the Vauxhall 16V DOHC with Webers, or Del'orto's?
<hr></blockquote>

Not exactly. This thread originally started out with a mistaken reference to the motor in a Jensen Healey being of Vauxhall origin. All Jensen Healeys came with Lotus designed, Lotus Manufactured engines designated as model 907. (Some may question whether the 907 is architecturally related to a Vauxhall or not but it is definitely Lotus designed and built.) The other reference that is highly peculiar is to “weber progressives”. Progressive Weber carbs like the DGV are downdraught units. There are no downdraught manifolds for the 907 and using those downdraught to sidedraught conversion thingys wouldn’t fit under a JH’s bonnet. It would be silly anyway since the standard factory (UK JH and US Lotus) manifolds are for Dellorto DHLAs and fit Weber DCOEs.

The Opel-Vauxhall 16V, which is shared across the two sister companies’ common platforms, is an entirely different engine from the slant 4 Vauxhall that the Lotus 907 resembles. The Opel-Vauxhall 16V is an excellent motor but not available in the US. The Cosworth YB is also unusual around here. If one is willing to have a car that is only supportable through (mostly overseas) mail-order either is a great choice for an LBC.

Since the Jensen’s 907 is already a DOHC 16V all aluminum engine such substitutions would be a lot of work and logistical annoyance for little or no net gain in output.

As for the Rover/Buick V8 there is enough room for it and I have seen it done. It is also a lot of work to do well. There is no such thing as an “easy swap” among engines and transmissions that don’t share common design features. Some are easier than others. At least with the Rover/Buick you don’t need to modify a lot of the car’s sheet metal. The people who have done it do appear pleased with the results.


PC.

Point taken, though I suppose you haven't done a lot of engine swapping and the task appears daunting.. In my book not modifying body work is an easy swap, and that's what I was implying.
I am fully aware the 907 motor is not Vauxhall based, as I have owned and rebuilt both. However I was unaware that the desire for the Vauxhall based DOHC 16V was a just a case of mistaken identity. I assumed the gentleman knew something about the Vauxhall motor even if it was or was not the basis for the Lotus 907.

I am not trying to jump on the "How little you know!" band wagon, just trying to expand on what could be a good idea for someone who wants to try something different


Given a choice, parts and availability not withstanding, I would take the more modern Vauxhall motor over the Lotus lump anytime.. Big power available there with very non Lotus like cost and reliability..

Cheers!

[ 08-13-2003: Message edited by: TypeRboy ]</p>

My interpretation (accurate or not) of the original question was that it was an inquiry for suggestions for “bolt-on power” and my responses were expressed with that level of effort in mind.

I too draw a mental line at doing bodywork as part of a swap but everybody’s different. To me, if it bolts in it’s easy, if it bolts in with some fabrication of custom parts like mounts, brackets, manifolds or driveshafts it’s moderate and if it takes bodywork and fabrication it’s difficult. I guess if you’re Franco Sbarro swapping an Allison into a Hillman Imp is easy.

The Opel/Vauxhall 16V really is a cool motor. It would be fun and quite practical to live with for anyone who has ready access to a support infrastructure. Although not easily serviced here in the colonies I was planning to put one into a car myself. Unfortunately that project is indefinitely on hold because I no longer have the target vehicle.


PC.

"I guess if you’re Franco Sbarro swapping an Allison into a Hillman Imp is easy."

Ha ha.. I like that one.. I completely agree with you.. And as I get older and have less time, swaps are just not really fun any more.. My Alfa 5 speed in the Elan is still giving me a headache ( speedo doesn't work..)

I saw a 2002 Westfield 7 with the boxhaul motor in it this summer.. What a great looking motor.. suposedly 200 hp.. but who really knows.. Still it spit back and ****ed worse than my car.. Those Webers are a great way to uncivilize any motor..
Actually mine doesn't spit or **** at all, so I was surprised to hear his do it..

Ooohh I do believe I used a bad word, perhaps I should have said tooted..

( First time edit )

[ 08-17-2003: Message edited by: TypeRboy ]</p>

Since this thread started out related to turbocharging, I though I'd comment that I found a cheap source of small turbos that might be useful in an LBC-turbo project....assuming one had good fabrication skills.

https://www.britishcarforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=11&t=000078