Lotus Elan

Just another 26R replica build attempt

PostPost by: 45DCOE » Fri Dec 31, 2021 6:39 am

Everyone has seen people attempt to restore classic cars of all genres but unfortunately have to abandon their project. Money issues and ensuing lifestyle changes, increased job workloads, personal family issues, bad supply chains, medical issues, and loss of motivation all contribute to this. After retiring, this will probably be my last rodeo to build something of true beauty and pride so I am motivated ( at least for now!).
I purchased a one owner 1967 S3/SE DHC in 1977 (chassis number 45/6131). It stopped running in1983 and has been in storage (under good to worse conditions) for 38 years. About two years ago I started to clean and disassemble the car half-heartedly. Figuring the engine being the most important component of a car, on a whim I called John McCoy of OmniTech Engineering to see if he could construct an engine around about a Stage 3 (150-160hp). He said ok so I crated up and sent him my old Weber cylinder head which looked good (the engine block not so good and unacceptable). John ran porosity tests and found it was too weak and would not hold up for long. It was then and there that I decided to go all in and asked him to do his 1950cc Twincam (185-190+hp) with the CNC ported Stromberg head.
That was one year ago from this past October. From the start, the supply chain was a problem as the essential Tallblock Ford Kent 1600 X/Flow Twincam Iron Block (711M6015BA) was back ordered till 06/25/21 and even then was delayed further. He was able to source one from Ivey Engines in Portland, Oregon. Apparently there is a great demand in England for these blocks for Ford Escort and Formula Ford cultists. Some of these Escort cars in England (as our friends across the pond well know) are truly mind blowing…..their reply to JDM cars in the States. It took about 10 months but John’s is a one-man operation and his top priority is refreshing twinkheads after racing season sent to him from all over. Engine all done.
Flew up to Seattle the first week in December, rented an SUV, drove 90 miles north to Bellingham, Washington, met John and toured his shop (more on this later), strapped the engine on a stand securely in the back, and then drove the 1,100 miles along the coastal scenic route back home to Santa Clarita, California….previously stopping for lunch and staying the night in pretty Bodega Bay, CA ( where Alfred Hitchcock’s THE BIRDS was filmed in 1963).
The engine was calibrated on a Superflow WinDyn dyno by Arnie Loyning’s Engine Services up in Portland (amazing that the Pacific Northwest has such a vibrant racing scene and some of the best Twincam builders in the country). The spec sheet and graphs showed 208.9 CHP at 7300 RPM and a more conservative. 164.9 C ft-lb of torque at 5700 RPM (will post spec sheets later). Even John was kinda surprised at the numbers as he said the engine just kept pulling stronger until he shut it down. He mentioned a max of 8000RPM was doable. He also said this turned out one of the better builds (forgot to ask how many 1950’s got to 200HP and 200HP plus), as he was extra careful and meticulous in all phases of assembly. Can’t rush genius. I also think the bolt on Stromberg manifold is easier and more precise to CNC port than the more angled Weber intake and extracts a bit more horsepower.
Here is a link to the Youtube video he posted showing the engine and it’s smooth sounding pull:

https://youtu.be/rawwisv79Ok

With the increase in power of course comes the need for a stronger differential, hubs, updated prop shaft, clutch, flywheel, and definitely a Dog close-ratio gearbox… all bending towards a 26R type reinforcement with no FIA restrictions to worry about. Realistically I hope to complete the build within 2 years with the help of all the great and respectful members on this board. Just by browsing these past years, I was able to learn a lot and now I will be able to ask specific questions as the need arises being the Lotus novice (but old fart) I am.
Thanks for listening,

Roy
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PostPost by: RichardS » Fri Dec 31, 2021 8:40 am

Wow!
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PostPost by: HCA » Fri Dec 31, 2021 9:16 am

Nice! With EFI it would be very sweet!
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PostPost by: 661 » Fri Dec 31, 2021 12:58 pm

You have the heart of the beast, just the body to go. Motivation shouldn't be an issue!
Fascinating to see/hear more on the Stromberg head solution
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PostPost by: rgh0 » Fri Dec 31, 2021 11:34 pm

Johns converted Stromberg heads certainly breath well :)

What cams did John use on this engine

cheers
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PostPost by: 45DCOE » Sat Jan 01, 2022 12:49 am

Hello Rohan…. I remember from your previous posts you were very interested in the cams he used. I need to talk to him about selling a gearbox so I will ask if these cams are his usual cams or something new he has ground to get to that elusive 200HP mark. So in the words of our illustrious White House press secretary, “Let me circle back to you on that”.
By the way Rohan… I have learned more from you on this board than all my teachers in college combined!
Thanks,
Roy
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PostPost by: rgh0 » Sat Jan 01, 2022 11:25 pm

Hi Roy

I have tried a range of Johns cams and currently use his .460 lift 300 degree duration seat to seat cam on the inlet and .450 285 degree duration seat to seat lift cam on the exhaust. This gives me over 180 hp from 1600cc at around 7500 and pulls to 9000+ rpm though I dont normally go above 8300 rpm . My engine is a different style to yours so interested in what John would use on your type of engine

cheers
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PostPost by: 45DCOE » Sun Jan 02, 2022 12:46 am

Gotcha Rohan….. I see exactly where you’re coming from now.

Thanks,
Roy
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PostPost by: stugilmour » Sun Jan 02, 2022 10:21 pm

Sounds great Roy. Welcome to the forum and thanks for posting.

I finally got my 1950 cc Omnitech running correctly in my Plus 2. Great engine. I don’t have dyno information on my particular engine, but assuming ‘only’ about 180 hp from what others have posted here. I never did get the exact cam specifications from John. You are going to love the results in the car! :D

My Plus 2 uses a MT-75 five speed, which John didn’t particularly like. With the engine flexibility he is probably correct. With my 3.55 diff the car is fine cruising in fourth. My starter setup was a minor PITA, but that may have been due to the non-stock transmission. Easier to check ring gear engagement and tooth bevels all out carefully before installing the drivetrain in the car. Also check clearances for the transmission shaft & throw out carefully; again my issues may have been because of the MT-75 but some modifications were required to button up the engine and transmission.

I opted to use Weber 45’s rather than injection, mainly due to the complications of fuel supply installation with the body in place ( and the fact John had supplied the new carbs already). Depending on how your project is scheduled and progressing, consider adding larger diameter fuel lines with a full return while you have access. For my car I wanted an in-tank high pressure fuel pump if I went the injection route to retain trunk space.

Speaking with John, the cool thing with the Stromberg conversion is he can apparently access everything with his CNC equipment so he can really tailor the head for mid-range torque or high rpm power in a very repeatable fashion, making all cylinders identical.

He basically removes the Stromberg runners and replaces them with a carefully machined bolt-on casting; I understand it is critical to have the bolt-on faces accurately machined to retain the head strength. All of these details are beyond me, but John sure makes a great engine! 8)

One item he routinely installs is an aftermarket oil pump. It works great, but does require a remote oil filter setup. I managed to mount the filter in the Plus 2 nose along with a foam style air filter and a breather catch can (the head modification removes the stock oil drain tube), which took a bit of fettling. The tall block was a tight fit under the Plus 2 bonnet. Kind of funny talking to John about the constraints as there must be a ton more room in his LoCort! All of this stuff is way easier before the engine is installed.

What ignition did your build use? I started out with a Pertronix, but we rapidly changed to an MSD, which required mounting a largish control box. In hindsight I would consider a full 3D system with a crank sensor, throttle position sensor, and coil packs, mainly based on others experience posted here. Looking at the video again it looks like the same MSD setup which should be fine.

I found tuning my engine for roughly 4,000 ft illusive, but I had zero experience when I started. The existing fuel supply and ignition (that had worked OK with the original Stromberg setup) was completely inadequate, which seemed to take me forever to realize and correct. :oops:

The Bellingham jetting was a few sizes too rich. Although I never measured engine vacuum, I found Keith Franck’s W idle jets and latest emulsion tubes essential to get things smoothed out. I still don’t have a finalized tune (too cold here now), but running way better when I put her away for winter. Keith send me both sizes of emulsion tubes as the engine displacement is right at the two litre changeover line; running so well on the smaller displacement tubes that I have not tried the larger ones and will be returning them to Keith. John prefers the standard Weber tubes, so was kinda on my own on this whole effort.

I was getting somewhat excessive fluids in the catch can. Taking advice from Rohan I lowered the oil level to midway between full and down a quart, which helped as oil is dragged up by the cam chain. I have read some suggestions about installing a sheet metal baffle by the front AN vent nipple, but have not checked this out closely yet. I have installed a threaded oil cap though, which really helped with an oil leak. Still working on very slight leakage at the cam cover nuts; going to try some O-rings or sealing washers over the winter. The rest of the engine seems well sealed and dry.

Regarding John’s build schedule, I understand he likes to batch build several new engines in one run, which I assume is way more efficient for machining setup. For others that might be interested, best to have a build booked and core delivered by late summer. Very pleased with the results, super guy. He was able to lend me a TC shipping box, but this required carb removal. All told delivering the engine on a simple aluminum stand was easier and made for a pleasant drive to the coast.

Going to be a great project! Cheers! If you are talking to John let him know I am super pleased. Also, if you know the call up for the gold cam cover paint I would love to touch mine up! John was having difficulty posting here, and not sure if he got it sorted out.
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PostPost by: 45DCOE » Mon Jan 03, 2022 6:44 am

Hello Hal (9000?). HCA…….you have a valid point going to EFI . I think the regular “L” Lotus block and more so the Kent Tallblock are at the outer limits of stability and reliability with a 1600, 1750, or 1950cc displacement. Maybe the way to extract that last bit of horsepower would be to go EFI. However, in the hands of an expert carburetion man (a disappearing breed I hate to say), these Weber’s can get darn close to EFI. John says the 1950cc Lotus Cortina he races feels just like fuel injection on the street and has that same torque response on the lower end.
Also, you just don’t see very many classical cars ( at least in the US) with Weber’s anymore so this just makes Lotus cars (Elans, Plus 2’s, Europa, and 7’s) stand out and to us , more huggable.

Thanks,
Roy
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PostPost by: 45DCOE » Mon Jan 03, 2022 6:56 am

Hello Graeme….. Encouraging words. I bet you are a good motivator!
On the Stromberg head, you probably have seen this older video from OmniTech. Some members may not have seen this and after watching it again, some things make more sense now.

https://youtu.be/PL0kcA2shRk

Thanks, Roy
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PostPost by: 45DCOE » Mon Jan 03, 2022 7:10 am

Hello Stu……. What a good and insightful post. You can have an engine built with all the specs and look dazzling but unless you install and test it, everything is moot. Your experience with a similar engine is a template to follow.
Let me put some thoughts together and answer some things you have asked that has transpired since your engine was built.
Talking to John was a sobering experience. Things are getting tougher and with the supply

chain issues, complete engine builds are considerably more challenging now.
I will post either tomorrow or later on.

Thanks,
Roy
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PostPost by: stugilmour » Mon Jan 03, 2022 7:35 am

Excellent Roy.

Took another look at John’s video that you linked to. It was the track portion (at about six minutes in) that initially intrigued me. John appeared to get as much jump up the hill as I was getting in my Esprit V8 during the West Coast Lotus Meet Track Day a few years ago (Pacific Raceways turn 3b to turn 5). I think his Lotus Cortina may even be lighter than my Plus 2 in touring trim.

I bet John hit save on the CNC porting data for your head!

Good times!

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PostPost by: 661 » Mon Jan 03, 2022 12:44 pm

45DCOE wrote:Hello Graeme….. Encouraging words. I bet you are a good motivator!
On the Stromberg head, you probably have seen this older video from OmniTech. Some members may not have seen this and after watching it again, some things make more sense now.

https://youtu.be/PL0kcA2shRk

Thanks, Roy

I hadn't seen that, thanks for posting, but I had heard Rohan discussing the magician of Washington, mainly in regard to his cams. I had previously discarded thoughts of a modified Stromberg head.
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PostPost by: My72Sprint » Fri Jan 14, 2022 11:51 pm

I also have a McCoy 1950cc with 193.5hp @ 6500, MSD, Webers etc.. McCoy rebuilt my diff with Quaife / 3:54 Ratio.
Running 4 Speed, Have considered a 5 speed upgrade but availability + mods , I’ll pass.

I have other cars (2020 C8 ) for long distance cruising ..
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