Lotus Elan

QED 420 MOP Setup Recommendations

PostPost by: 1owner69Elan » Sun May 03, 2020 8:16 pm

rgh0 wrote:From those who have Dave Vegher built engines I would be interested to know what timing he used on your cams and what cams he used as i have not seen data from his recommendations

cheers
Rohan


Specifications on my Dave Vegher 1700 twincam. This engine was built for the street, not like most of Dave's race motors.

Cams:
Kent brand. I don't know the part number. (I believe these were recommended by Tony Ingram as a good high performance street cam)
0.44" lift
Duration: 250 deg @ .050" lift
MOP: 105 on the intake, 107 on the exhaust
Valves:
Intake: 1.625"
Exhaust: 1.375"
Carbs:
Weber 40's
32 mm chokes
Airbox: Oversize custom Weber box with cold air trunking (Standard airbox robbed 7 hp)
Exhaust: TTR Extra Large Bore Race System
Head: SAS new Weber casting. Street ports, although Dave increased these, as well as other head "tweaks", from as delivered.
CR: 10.3 : 1
Pump gas (91 octane, (R+M)/2

Result: 181 hp @6900 / 143 lb-ft @ 5100
Torque relatively flat, shown on dyno.
dyno Vegher.jpg and
Lotus TC Dyno.jpg and
'69 Elan S4 SE
Street 181 BHP
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PostPost by: rgh0 » Sun May 03, 2020 8:46 pm

Thanks for that data. That Kent cam is very similar to the McCoy .44 lift cam i have used with similar MOP timing. While seat to seat duration and total lift are not the total determinants of a cams performance they tell you 70% of what it will be like. Duration for lift at .050 inch and 0.200 inch lift checking points tell you a bit more and area under the lift curve ( inch degrees) at these points tells you a bit more.

cheers
Rohan
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PostPost by: Pfreen » Mon May 04, 2020 11:24 am

Wow 1owner69elan!

That is one impressive engine. I’ll bet 99% of twincam owners who want a street engine are jealous. I am.
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PostPost by: knockoffnut » Wed May 06, 2020 8:20 pm

it makes sense to set the cams for more lower end torque for a road application. When I built my twincam for my S3 Elan I played around changing offset dowels until I found a cam position that gave me a nice amount of low end torque and still lots of high end power, but as it was a road engine I definitely wanted the driveability of the low end torque. My point is it is easy (and fun :D ) to try different cam settings after the engine is built, and "trust your bum"... if it feels right then it is right. :wink:
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PostPost by: vstibbard » Fri Jun 25, 2021 9:55 pm

My experience back in the 80's with my S4SE DHC (MJY740J) which was delivered from factory with the Stromberg head with big valves and D types (Sprint) cams, I had Ed Winter rebuild and port the head and Ken Snailham (WED) built up the bottom end and ran engine in dyno, then did final set up, it had 10.3:1 comp, with some tweaking of timing and bob weight springs, richer needles, it had twin muffler exhaust, this engine produced 128bhp with similar torque to a Sprint.

Only element missing was the carb sound!!

On balance I had performance and when touring in France to LE Mans's and Med I'd get 40miles/gallon and on motorways mid to high 30's!!
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PostPost by: Billmack » Sat Jun 26, 2021 5:23 pm

There is really no substitute for running your actual motor on the dyno. A few days of testing scientifically managed will tell you a lot. Of course you can also wear out your engine a lot.
Had an elan come and go in my shop with one high lift cam on the intake side and a sprint like cam on the exhaust. Really nice running engine for street use. I' m told it did something in the 150's on the dyno a couple rebuilds ago. I was impressed with the tractability and how it really flew out of a corner.
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