Lotus Elan with stroked twincam

[gdcomputer]

At LOG 37 a fellow Lotus Ltd member let me drive their Elan which had a stroked T/C in it. The car was a bit rough but the engine was amazing. Of course I have lost his name and contact info so if anyone knows who this is could you have them contact me.
Gary David
Macedonia, OH
[email protected]

[fotsyr]

Most probably a 1600cc xflow crank & rods with special pistons. I built one years ago for a 7 owner, 1690cc, pulled from 2-7k. About 148hp. Great set up.
chris

[holywood3645]

If your looking for a blueprint to build an 711M tall block engine too, I would strongly recommend the QED420S spec, the block is decked to be approx 4mm taller than the standard block. It uses the standard 1600 crank and rods. Most of the parts can be sourced in the US.
They claim 145-150 Hp and good torque below 2000 rpm.
I have one in my S4 elan, and I can say it will bring you to the point where Adrenaline meets Fear…. Very quickly.
However, it’s very smooth an refined unless you need some extra excitement.
QED are in the UK, and are very accommodating.

[Mike Ostrov]

Hi, Gary. I built a 1725 cc Twin Cam. LB block, B cams, 10.25:1 static compression ratio, 84.5 mm bore, 1600 x flow crank and rods with appropriate pistons for my Elite/Elan MK II. Had to use a Stromberg head as the 1971 Pinto Estate Wagon C-4 automatic is vacuum controlled. Seems to do fine with the automatic and the 1895 pound weight of the Elite/Elan. Cheers. Mike.

[2cams70]

If your looking for a blueprint to build an 711M tall block engine too, I would strongly recommend the QED420S spec, the block is decked to be approx 4mm taller than the standard block. It uses the standard 1600 crank and rods. Most of the parts can be sourced in the US.
They claim 145-150 Hp and good torque below 2000 rpm.
I have one in my S4 elan, and I can say it will bring you to the point where Adrenaline meets Fear…. Very quickly.
However, it’s very smooth an refined unless you need some extra excitement.
QED are in the UK, and are very accommodating.

The main thing in life is that one is happy with whatever choice they have made. I can vouch for QED. They are much more helpful when there are issues than that other large company supplying parts in the UK. I'm glad they now have some good competition in the English Ford space at least - companies such as motorsportools.com.

[rgh0]

If your looking for a blueprint to build an 711M tall block engine too, I would strongly recommend the QED420S spec, the block is decked to be approx 4mm taller than the standard block. It uses the standard 1600 crank and rods. Most of the parts can be sourced in the US.
They claim 145-150 Hp and good torque below 2000 rpm.
I have one in my S4 elan, and I can say it will bring you to the point where Adrenaline meets Fear…. Very quickly.
However, it’s very smooth an refined unless you need some extra excitement.
QED are in the UK, and are very accommodating.

I agree with what's said except for decking the block by 7mm to reduce the height to 4mm above the original 1500 block. The original top deck is around 12 mm thick and you are reducing it to 5 mm thick. As the water passages under the deck are a rough casting there may to +/- 1 mm in the deck thickness. You may be Ok and you may be not. It really depends on the individual casting and what else you may be doing such as sleeving. You also need to ensure the head bolts don't bottom out in the block threads and you have enough thread left for full strength thread engagement in the block

If building a long stroke twink I personally would prefer to fit a long stroke crank into a standard 1500 block and standard other components with a low compression height piston. My second alternative would be to build it based on a standard height 1600 block with all the detail changes needed e.g. the taller special front cover or spacer and the longer timing chain tensioner arm and 122 link chain, changed engine mounts, longer oil drain tube, bonnet clearance issues etc.

Various other combinations of rods and pistons and cranks give different required deck heights between the two extremes of the standard 1500 or 1600 blocks. We are really spoilt for choice

cheers
Rohan

[holywood3645]

Rohan,
it ran for 8 years with no problem’s.. well, until the water pump went.
New bean cassette pump, then oil seals & guides fitted thanks to Omnitech,
upped the compression a little to see if it helps performance…we willl see!
If it’s as good as it was before the water pump went, I’ll be very happy!
Oh reducing chain length to 121 link. The angles in 122 were very sharp and wanted to get away from the Quadrant tensioner mods

Thanks
James

[rgh0]

I agree your block looks like its good and could take the decking if it ran well for 8 years It is just not something i would personally recommend given the potential risk

Have you found a source for the 121 link chain. Tony Ingram should know one locally to you I would have thought

cheers
Rohan

[holywood3645]

Tony told me about them, I’ll be honest, I’d never heard of them and didn’t know it was an option.
They are all over eBay here, but they are called an offset link!
The chain type is 06B if anyone needs that info,
Thanks
James

[nmauduit]

a side issue in fitting a plain 1600 block in a 2 seater is bonnet clearance... there is not a whole lot of room, and 12mm extra can prove difficult to accomodate.

[gjz30075]

To answer Gary's question, my approach would be to contact Cora Gregoriie (a member of the Lotus Ltd board)
to see if she has a list of attendees and the car(s) they brought. Might be able to parse it out from there.

[wobblyweb]

Hope this might be of use, sorry if it is not in order.
From the David Vizard book priced at 16 Shillings.

[Mazzini]

a side issue in fitting a plain 1600 block in a 2 seater is bonnet clearance... there is not a whole lot of room, and 12mm extra can prove difficult to accomodate.

I read somewhere that on a Weber engine, using an exhaust engine mount on the carb side drops the engine by quite a bit.

Also isn't the casting on the side of the 1600 different? Isn't the block wider? Minor machining corrects this or I guess the same effect is possible by machining the spacers.

[holywood3645]

The exhaust side engine mounts need cut down to 1” from side of block.
Sorry, forgot about that until you mentioned
James

[2cams70]

I know a lot of people seem to change the engine position at will but you've actually got to be a bit careful with driveline angles. If you get them too far out you may end up with a vibration.