Qed 360 cam on stromberg

PostPost by: Mileso » Thu Apr 11, 2024 1:31 pm

Hi. After any feedback from people who have actually done this please.
I have standard stromberg twincam s4. Fully rebuilt engine a few years ago goes well.
Considering a bit more pep via qed 360 cams and no further mods.
I don't really go above 5000rpm too often so not interested if only benefit is at the top end. Would it be a noticeable boost across the range?
Also will save my money if only 10bhp to be expected.

Any real experiences out there - engine coming out soon as clutch thrust bearing making suspicious noises after only 3 years !
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PostPost by: rgh0 » Fri Apr 12, 2024 1:25 am

What cams do you have now? The QED 360 is essentially the same as the Lotus D type Sprint cam. I dont know what cam the Stromberg S4 came with, my Weber standard S4 came a B cam. If it has the B cam ( no grooves) it should give 10 to 15 hp and better midrange torque. You may need to change the carb jetting also. If you still have the cast exhaust manifold its worth changing that also.

cheers
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PostPost by: Mileso » Fri Apr 12, 2024 6:59 am

Thanks rohan. Currently on a c cam, single groove. The miles wilkins book suggests they go really well after the change but no data.
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PostPost by: vstibbard » Fri Apr 12, 2024 7:25 am

I had an S4SE on Romberg which had d type cams and big valves with just under 10:1 compression rebuilt in uk years ago. On QEDs engine dyno tuned by Ken Snailham it made 126 bhp can’t remember torque and 38mpg!!
We changed needles, heavier spring and advance curve.

I had two friends with Sprints one semi close with 3.77 did the other Cr and 3.55 and the SE with semi and 3.55 was marginally slower in sprint but very responsive in gear acceleration.
QED's view on strip down was mine had D type and big valves from factory as well.
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Last edited by vstibbard on Sat Apr 13, 2024 2:45 am, edited 1 time in total.
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PostPost by: sng » Fri Apr 12, 2024 10:07 am

My UK S4 SE Stromberg equipped engine has D-Type cams which I believe was the out of the factory specification and well documented in Miles Wilkins book. The car has a 3.55 diff and when tuned correctly pulls very well across a wide rev range making it easy to drive in modern traffic and gives an MPG that is easy on the wallet. Always wondered if fitting a 3.77 diff would give it the edge in any 0-60 drag race with a big valve equipped car to the extent I have a 3.77 diff sitting on the shelf but waiting for a green speedo drive to come up before experimenting.
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PostPost by: JonB » Fri Apr 12, 2024 5:45 pm

Are you saying an S4 SE on Strombergs with a D cam and HC head would outdrag a Sprint?

That is what I am restoring…
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PostPost by: vstibbard » Sat Apr 13, 2024 2:47 am

Yes, having said that. my engine was carefully rebuilt, head flowed by Ed Winter and bottom end prepared by QED and then run in on engine dyno by them before final power tune. V
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PostPost by: elans3 » Sat Apr 13, 2024 9:40 am

sng wrote:My UK S4 SE Stromberg equipped engine has D-Type cams which I believe was the out of the factory specification and well documented in Miles Wilkins book. The car has a 3.55 diff and when tuned correctly pulls very well across a wide rev range making it easy to drive in modern traffic and gives an MPG that is easy on the wallet. Always wondered if fitting a 3.77 diff would give it the edge in any 0-60 drag race with a big valve equipped car to the extent I have a 3.77 diff sitting on the shelf but waiting for a green speedo drive to come up before experimenting.

I've had both. My view is that anything SE or above power, then a C/R box with a 3.55 diff is the sweet spot. I think there's hardly any difference in 0-60 purely because of the long first gear of the 2.5 : 1 CR box, so you're still accelerating to 50+mph while your mate with the 3.77 has already changed and building up again. OK, you'll have to change before 60, but there'd hardly be any difference in the two, as he's still catching up.
I love the combination of CR and 3.55 as it also gives a bit more relaxed cruising on the MWay.
Current :- Elan S3 DHC SE S/S 1968,
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Elan S3 DHC S/E 1966
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PostPost by: vstibbard » Sat Apr 13, 2024 10:44 pm

I’m agree, I’ve had two elan’s one S2SE and s3SE with CR and 3.55, the S2 I suspect had the 3.55 fitted later.
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