Hey, as you maybe aware I'm running an AEE in a mk4 on bike carbs.

Using a mk2 vac advanced dizzy...

Technically I have no rev limiter, I can go flat out in first or second etc (over 40mph in 1st lol) but it seems to get to 6800 and go no more, like the spark is weakened or something not letting it rev anymore.

So basically, is my rotor arm limiting my revs? I know others rev theirs to 7.5-8k.

I'm still on hydraulic lifters, bottom end etc is balanced and a 268 cam?

Nick

More likely your engine is out of beans by then. You'll need a pretty ballsy camshaft to be making useful power up there.

The AEE doesn't like to rev too much due to the stroke length. Equally, the lightening wont increase your power, more like the safety of that power.

So i think to make near 7k with an AEE is already very good.

I'm not particularly bothered as like you say won't be making any power etc, and on standard valve springs, I'd have just thought would go a bit higher, two other high spec aee's rev over 7k they just have a 272 cam instead?

saying that it's not all fully setup yet :) I didn't think it was a rev limited rotor arm but thought I'd ask :)

my 8v went up to 8k :p was scary fuel drinking stuff!

Seeeeee mines shitt haha

Eric had a 1.3, so id doesnt count. It still ran out of puff at 70! The torque of the AEE is much more preferable.

I'm not sure standard valve springs are likely to be resttrictive either. Valve bounce only comes into play at really high revs, not a poxy 6800! Your cam could be the restrictive part, but then how is your exhaust and inlet system? These will all have an effect

make that 80 sir! beast! i think it was set up wrong tbh haha. fast up untill then though!

6800 is a bit low though?

The chokes in the carbs might be restricting the revs if they're too small. They do exactly what they say on the tin, they "choke" the air off once a maximum air speed has been reached for that diameter choke. Need more revs? Choke size or inlet area needs to be increased

^^ The carbs are bigger than the inlets, so no restriction there. But the flat slides might not be opening fully, which may be restricting the choke size available.

Yeah, 37mm carbs, then joining rubbers reduce to 34mm, which is same size as inlet tracts on manifold and ports are blended to match :) not sure I'm keen on chopping the springs down as they need to be an identical rate for balance

My betting is on the fuelling and ignition setup.

There's physically nothing on the mk2 dizzy that can limit revs and unless you have an aftermarket rev limiter attached to your coil, then it's not going to limit. Some dizzys have a centrifugal limiter, like my old mans Lotus, reaches a certain rev limit and pushes a spring by centrifugal force to stop the contact and therefore no spark. The mk2 dizzy does NOT have this.

Mine can and will rev until it goes bang, i'm not overly excited about that prospect, but I reckon it could happen. The only key difference between mine and yours is fuelling and ignition setup i suppose.

Edited 26 November, 201114 yr by leeds_finest

Same, no limit and will rev up to silly (only done it once or twice, going to floor it from a junction with the car not in gear )

Hence the need for a limiter (with launch) when I can afford it :)

Yeah that's what I mean haha, I know the setup is holding it back from it's full potential at the minute !

Sander_beer, have you had your distributor modified for the ignition curve?

also, what rpm with no load should the chokes be fully open?

As above.

There's nowt in your distributor to limit the revs, which is just as well, because if you cut off the spark, but keep the engine turning, you would sooner or later finish up with a lot of petrol vapour in the exhaust system, this would eventually go off with a mighty bang!

It also depends on if the limiter is a hard or soft cut type.

Hard cut is what you hear in maccy d's car park at night as the car bounces off the limiter

Soft cut kicks in just before so the power dies off then back on till it hits the limit again. almost as if your taking your foot off.

I thought mk2 dizzys did have a centrifugal rev limiter in them? Could well be wrong though.

Hard cut is what you hear in maccy d's car park at night as the car bounces off the limiter

I lol'd @ the above.

...normally attached to the Citroen Saxo variety, with a peak cap wearing chav turning the key on and off at full revs to get it to pop flames.

There's a word for those people, oh yeh, T0$$ER$

I thought mk2 dizzys did have a centrifugal rev limiter in them? Could well be wrong though.

The fact i can rev mine off a standard 6N clock says not :)

...unless of course mine has been previously messed with? I reckon revs were limited on a mk2 in a different way or maybe the fuelling/ignition ran dry before fatal rev heights?

nah they maybe limited, but its certainly higher than said figures, as people rev to near 8k on a mk2 dizzy so!

saying that i pushed it a bit earlier and it revved to about 7, just dont know how far i can go, dont really wanna find out the hard way haha, indicated over 70mph in 2nd gear......on standard circumferance wheels?! awesome!

nah they maybe limited, but its certainly higher than said figures, as people rev to near 8k on a mk2 dizzy so!

saying that i pushed it a bit earlier and it revved to about 7, just dont know how far i can go, dont really wanna find out the hard way haha, indicated over 70mph in 2nd gear......on standard circumferance wheels?! awesome!

yeah my old one would go just over 8k but i didnt like doing it! was dynod up to 8k though :)

Edited 28 November, 201114 yr by erixtar1992

nah they maybe limited, but its certainly higher than said figures, as people rev to near 8k on a mk2 dizzy so!

saying that i pushed it a bit earlier and it revved to about 7, just dont know how far i can go, dont really wanna find out the hard way haha, indicated over 70mph in 2nd gear......on standard circumferance wheels?! awesome!

I very much doubt the car/engine that said distributor came from had an 8k rev limit!?

I'm sure mine doesn't limit at all, and neither does most peoples who run that dizzy, any flattening off you experience at high revs is due to fuelling or ignition differences.

Hard cut is what you hear in maccy d's car park at night as the car bounces off the limiter

I lol'd @ the above.

...normally attached to the Citroen Saxo variety, with a peak cap wearing chav turning the key on and off at full revs to get it to pop flames.

There's a word for those people, oh yeh, T0$$ER$

Hard Cut launch and Soft Cut limiter is the way to go.

Bouncing off the limiter at 3000rpm next to some peak cap wearing wannabe is always good for comedy, he sits there spinning up while you vanish into the sunset.