Lotus Elan

Engine hot off the dyno!

PostPost by: 1owner69Elan » Thu Dec 17, 2015 12:01 am

I am the original owner of a 69 S4 SE DHC that I picked up at the factory July 69 and brought back to California.

The car had been sitting (usual problem - water pump) for the last 13 years. Now having the time, decided to get it back on the road. The car was basically in good shape, no rust, engine and driveline fine, original paint, .. but figured since I pulled the engine that I might as well improve things after 46 years of ownership. Some may disparage the departure from strictly original but I am certainly keeping things in the original "spirit". No body changes, keeping Lotus twin cam power, etc. But, the selfish aim is the car is purely for my driving pleasure so upgrades were in order across the board (alternator, oil cooler, 26R cooling, CV joints, uprated prop shaft, uprated differential outputs, Quaife ATB, uprated stub axles, adjustable suspension, new springs/shocks, removable water pump, Pertronix ignition, etc) .

The engine has been stroked (1700 cc) and I put a new SAS head (street -not race- porting) on it so I could finally have the Webers that I didn't get when I bought the car in 1969. Put on Weber 40's not 45's. The original block has been retained. It really didn't have much wear. So the engine number "matches" but as you will see performance is a bit different.

The goal of the engine build was to have a reliable, torque oriented motor for the street.

The dyno verdict just in from my engine builder (well known top builder, supplying twin cams for a lot of racers and a few for the street like mine). The numbers are impressive:

141.5 lbs peak torque @ 5000 then slight dip and back above 140 at 6000
Makes 133.1 lbs torque at 4200 and never drops below 133 all the way to 7000.

179.6 bhp @ 6900 (just about 180 bhp !) Torque at peak hp: 136.7

91 Octane unleaded California pump gas.

Compression ratio 10.2, reduced total advance. No pinging.

Should be exhilarating to drive after I finish installing all the suspension, driveline upgrades - that are my job. A challenge will be tire size as I don't want to do flares.

I think these excellent torque and bhp numbers are the result of the combination of a meticulous top builder with decades of experience and proven success along with the potential contribution from a new (replica), better breathing, twin cam head from SAS. I think the care taken in the build is evident from the pictures.

Some pictures
image2-5.jpeg and
image1-3.jpeg and
image1-8.jpeg and
image2-4.jpeg and
image1-9.jpeg and
image1-7.jpeg and
image1-4.jpeg and
image2-3.jpeg and
'69 Elan S4 SE
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PostPost by: seniorchristo » Thu Dec 17, 2015 12:18 am

Sounds like an impressive rebuild. Let us know how your first outing goes.
Chris :)
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PostPost by: 1owner69Elan » Thu Dec 17, 2015 12:49 am

Probably going to be a little while before I am on the road. Have quite a bit of work to do. But that motor is going to be staring at me to get my part done.

Will post my driving impressions when I get there.
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PostPost by: rgh0 » Thu Dec 17, 2015 9:37 am

looks like a very nice engine build

What cams did you use?

cheers
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PostPost by: gjz30075 » Thu Dec 17, 2015 9:56 am

Looks really good. Who's the "well known top builder"?

What's an uprated propshaft?
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PostPost by: stevebroad » Thu Dec 17, 2015 11:56 am

Very nice.

Yes, it will be interesting on the road :-) Back in the late 70s early 80s I was running 168bhp at the wheels in my S3. There was not a lot around that could stay with it back then, only bikes over 500cc :-)
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PostPost by: ceejay » Fri Dec 18, 2015 3:36 am

Congrats on the nice resto.
Questions:
1: What is the small alternator off?
2: I note that you epoxied the internal surface of the sump, is that better than say scothbrite/polishing of the metal.
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PostPost by: StressCraxx » Fri Dec 18, 2015 4:21 am

ceejay wrote:Congrats on the nice resto.
Questions:
1: What is the small alternator off?
2: I note that you epoxied the internal surface of the sump, is that better than say scothbrite/polishing of the metal.
Ceejay


Not sure of that specific alternator, but the ones sold online for conversion are from a 95 Suzuki Samurai, 1.3L, JL or JS. The replacement alternator is new, made in China. I has been in the car almost 3 years without a problem, comes with a lifetime warranty.
Mfgr is World Parts Systems Part # is 14684N. It replaces a Denso 100211-141, 100211-155, 100211-407
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PostPost by: ceejay » Fri Dec 18, 2015 4:49 am

Thank you for that.
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PostPost by: 1owner69Elan » Fri Dec 18, 2015 6:39 am

In response to the various questions:

1. The engine builder is Dave Vegher, Veloce Motors West, Petaluma, California. Dave provides and maintains twin cams for a lot of the historic racers. He also is a three time national SCCA champion (80's) in an Elan as a driver/mechanic. His focus is primarily racing but occasionally does a street engine. Dave has been creating top flight twin cams for a long time. He does a lot more than just put parts together. His preparation of everything and knowing what works together is remarkable. Granted my 1700 cc street engine is a no compromise project - but Dave delivered the goods: Over 180 bhp and 143 ft-lbs (today's dyno numbers), at relatively low revs, and a flat torque curve. There was some skepticism about these numbers on another post. These are not falsely inflated numbers - many, many twin cams and other engines have run through his dyno as reference. The proof is in the pudding - his engines win races and have done so for a long time. He has a large and loyal international clientele. By the way, the engine on the dyno was as smooth as silk, rock steady at idle all the way to 7000 rpm (where we stopped). My old engine was never like that.

2. The cams used in my engine are via Tony Ingram, another top builder (an ex-pat Brit in Santa Barbara, CA). I will have the spec tomorrow after I get the complete build sheet.

3. Dave epoxied the inside of the sump as well as the entire inside of the engine to ensure that everything was absolutely sealed and maintaining a rust free surface.

4. Build sheet will reveal the origin of the alternator which I will post. Notice also, in proximity, the sealed dipstick that Dave neatly fitted. Another example of a small but meticulous detail. I also noticed today that he put set screws on the sides of the freeze plugs to ensure that they stay fixed no matter what (we don't freeze here). Also, he safety wired the alternator bracket bolts. Lots of nice extra details.

5. By the way, we put a stock S4/Sprint air box on the engine and found a 7 bhp drop in the peak hp (albeit down to 174 - not to be greedy). I had bought the Weber air box/back plate via the usual suppliers since having a Stromberg head before I didn't have a Weber setup. Comparing the S4/Sprint air box to the one on a genuine 26R that Dave has onsite, the volume of the S4/Sprint one looks to be less than half. Clearly cannot keep up with the flow of this engine. I guess we are going to have to fabricate one like the 26R unless they are available somewhere (anybody know?). I went back to look at the 69 S4 restore that Jay Leno did (not his 26R) and Jim Hall (Chief Fabricator) mentioned that they had to make a mold from scratch for the Weber air box (Leno's 69 S4, like mine, also originally had Strombergs). The air box shown on Leno's S4 is definitely larger than the S4/Sprint version that I recently bought. Leno's stroked engine makes something like 160 bhp. Wonder if Jim would give me access to his air box mold. Anyone know how to contact him?
'69 Elan S4 SE
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PostPost by: 1owner69Elan » Fri Dec 18, 2015 6:47 am

There was another question about the uprated propshaft.

This was supplied by Tony Thompson Racing (UK).

Stated to have a stronger tube and higher quality joints. Delivered fully balanced.
'69 Elan S4 SE
Street 181 BHP
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PostPost by: oldchieft » Fri Dec 18, 2015 9:46 am

The are a couple of nice steel cranks sitting by the door, I would put them somewhere safer.

Who is the maker? 84mm stroke gives nice toque, but needs a strong starter to turn them over.

Jon the Chief
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PostPost by: Certified Lotus » Fri Dec 18, 2015 2:15 pm

Nice dyno results. Nothing better than torque for a quick Elan on the road :D

I have a brand new QED airbox, backing plate, hose and airfilter available for sale if your interested. I bought it to use on my 64 S1 as I also built a high performance TC and needed extra airflow, but is a bit too big too fit in the early cars. The front of the airbox doesn't clear the edge of the bonnet. Later cars (S3/S4) are not a problem.

I'd like to know who makes the alternator bracket you used. I need one of those.
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PostPost by: 1owner69Elan » Fri Dec 18, 2015 6:31 pm

Regarding the QED air box. Can you tell me its approximate internal depth measurements? Trying to guesstimate the volume compared to the S4/Sprint stock ones that I got - that are clearly too small.

I also ran across a website that seems to sell a nice air box for the Elan even if the fellow seems to be a Lotus Cortina specialist. http://teamdeville.co.uk/product/lotus-elan-air-box/

Looks similar to the 26R box I was looking at yesterday.

Anyone have any experience with team deville?

Thanks,
'69 Elan S4 SE
Street 181 BHP
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PostPost by: nmauduit » Fri Dec 18, 2015 7:01 pm

1owner69Elan wrote:
5. By the way, we put a stock S4/Sprint air box on the engine and found a 7 bhp drop in the peak hp


What kind of air filter (if any) did you have for that test, the stock twin tube banjo one - or did you have just the intake cover made of fiberglass opened freely (the stock S4 is squarish I believe, not the one with the end next to the firewall rounded) ?
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