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Yes, Duplex...... peace of mind I say

Duplex chains are heavier and require more effort to rotate.

A good simplex chain is perfectly fine.

I believe that Swifty uses simplex chains on all his engines nowadays.

mk1 wrote: ↑Tue Jan 17, 2023 2:53 pm I believe that Swifty uses simplex chains on all his engines nowadays.

if i was building a race engine I'd go highest quality single i could find, rotational losses and all that...
But for everyday longevity and not chasing every HP i use duplex as default.

Hi,

thanks for all the supplies, I'm not looking to vastly improve anything, just a std set up with std rockers...

Simplex JWIS chain. Has an A Series timing chain ever snapped? I've seen them so shagged they've worn through the timing cover, but never broken.

Vernier gear worth it?

I prefer using an offset woodruff key. The vernier adds an extra level of complexity that can come loose

There’s also the type with extra key ways on the crank sprocket to dial it in
https://outlawspeed.com.au/shop/cs8000

It's absolutely worth timing the camshaft in properly as well as having a good distributor built with a correct advance curve. You can lose 10 bhp with ease if they aren't right.

That and bumping up the compression ratio to 9.75:1 to run on super unleaded will really give it some sparkle. A good standard 998 Cooper was only a couple seconds slower to 80 mph than a 1071 S.

mk1 wrote: ↑Tue Jan 17, 2023 1:40 pm Another vote for the evo 1 or alternatively Calvers CST229 is a good bet too.

Personally I put duplex's on all my engines, not sure whether it's really necessary though.

997 type cam isn’t quite the same as the 998 so will the dizzy need re curving?

Please excuse my ignorance!

snoopy64 wrote: ↑Tue Jan 17, 2023 1:18 pm Ok, machining all sorted, now +20.

Can anyone recommend a cam close to std and is it worth fitting a duplex timing setup?

Racers will fit Simplex to reduce rotational weight, but in a road car, I would go for Duplex, I dont think Simplex is likely to break, but long term, Duplex is likely to be less prone to stretching and rattling.

snoopy64 wrote: ↑Fri Jan 20, 2023 6:27 pm

mk1 wrote: ↑Tue Jan 17, 2023 1:40 pm Another vote for the evo 1 or alternatively Calvers CST229 is a good bet too.

Personally I put duplex's on all my engines, not sure whether it's really necessary though.

997 type cam isn’t quite the same as the 998 so will the dizzy need re curving?

Please excuse my ignorance!

Absolutely.

The 998 Cooper camshaft is very timid (230/252?) from the Austin 1100. BMC undoubtedly fitted this to restrict power to 55 bhp or so. You only have to compare period road tests to see how much faster it was than a 997.

The 997 Cooper/MG Metro cam is 252/252 degrees and that cam has been improved further still.

As previous posted.. I’m not looking for more performance.. just yeh closest modern equivalent to what I had (not confident in having the old cam reprofiled and treated)

Would the infamous sw5 be better low down or is that another 997 variant?

Choices to liven up a 998, but still very civilised, would be....Piper 255, then either EVO1 or 567.
No more than 10.5:1 CR

Many moons ago, my cam of choice for my 998's was the Kent MD266, it's a cam I really enjoyed at the time, but it definitely moved power and torque further up the rev range. This was in the days before the Calver and Minispares items existed and these are more than likely better cams now for all round road use.

Good thread for 998 Cooper and standard 1000 car owners wanting to keep them almost standard - and civilised. I like your take on this subject Snoopy. I'm following it with interest if I get this bloody late 1970 reg Cooper that I want to get my hands on.....

It’s messing with my head Peter, lots of info but I haven’t distilled it to a conclusion yet!!

Yep....., know wot you mean. I have been printing the thread off and one windy and rainy evening I'll sit down with a glass of fine Scotch and condense it into a rough book.

I am taking on board what Minisprinter and Costa Brava have to say about cams.

snoopy64 wrote: ↑Sun Jan 22, 2023 8:34 pm It’s messing with my head Peter, lots of info but I haven’t distilled it to a conclusion yet!!

I understand about not wanting to modify it, but you can tweak a 998 to great effect making it a bit more lively without ruining it. Just 5-10 bhp, a bit more torque but still the same idle and flexibility.

If that’s a side effect of fitting what’s best available then great…but struggling what’s the easiest option