Beta on the Rollers

[HFStuart]

Last week I finally got my Spider down to Peter Baldwin's rolling road to sort out it's running. For those of you who don't know Peter is the man to take your A series to for setup, a successful touring car driver and (crucially) has forgotten more about carb setup than I'll ever know.

Good news and bad news then.

He sorted the flat spot - a bit of rubber across the top of the a main jet  - oops!
He sorted the slow running - it was a mile out.
He did a power run and it made over 140bhp !

Now I have no idea why it's making more than it should as it's a bog standard 2.0 (re-bored +0.8mm) that I assembled a couple of years ago. Anyway the problem is my Huco low pressure fuel pump can't keep up ! So after about 5 seconds the mixture goes lean and the power drops off.

It's just about the best £75 I've spent on my car - as high revs, full load and lean mixture = detonation and dead engine. I'm going to replace the pump with a Facet and a pressure regulator and take it back to see what else he can do with it.

One thing I noticed during the tuning was my rev counter reads low up to 4000 rpm and then high after that. In fact at a true 950rpm it read about 500. Any ideas as to shy ?

Stuart

[hutch6610]

I keep telling people to check the accelerator pump jet - especially the "o" ring underneath it.

I don't want to be a stick in the mud but you have a standard 2000cc single carb Beta (believe me they are much faster than the book figures) and i would expect the best would be about 120bhp.
You should be able to run with or out accelerate a 1.9 Peugeot 205 GTI and you have more power than a VX.
Sure his equipment is not out of whack - i know it sounds really bad of me to to cast doubt on the power figures, also what was the power figure he got at the wheels?

Admittedly for some reason your car needs the extra fuel and i would think it would want up jetting also.

Whats the rest of the car like, sure you don't have a gas flowed head or some interesting cams without knowing it, i would think you would require a larger bore exhaust as the standard after market systems like TI-max and Walker are real killers of power - something Must be doing it for you.

Post your results on Guys Forum to see if he could shed some light on whats going on.

This your fuel pump?
http://www.fastroadcars.co.uk/shop/index.php?act=viewProd&productId=29
Where is it fitted - under the bonnet?


Guy Croft would flow the head, sell you 40's on a manifold and fit higher compression pistons and the Facet system to achieve 150bhp odd.
Could you do a compression test and post it here - you should have 200psi if you have a really good Beta.

The rev counter is quite old and probably has sticky spots and don't forget the components on the circuit board inside, the capacitors etc wont last for ever.
Just change it.

Anyway congratulations are in order if the figures are correct ..... i know, i know i sound like a right doubting Thomas!.

[HFStuart]

I keep telling people to check the accelerator pump jet - especially the "o" ring underneath it.

I'm not a complete idiot you know  the carb was overhauled with new parts when the engine was built. Where the bit of rubber came from I've no idea but the problem is cured now.

I don't think you're being a doubting Thomas as I'm 100% with you in that I'd expect it to make 120ish too and there are only two options  - either his kit is wrong on my car isn't as standard as I think. The car has always felt pretty quick off the mark but obviosuly in anything other than 1st and 2nd it's running out of puff do to the issues with the pump

His equipment is old but the figures he gets are checked by some of the racers he works for on other roads and they're there or therabouts. The car is standard, the head valves etc are not modified in any way. The cams were form Guy croft and are supposed to be standard too (the originals were well past it)  About the only thing I didn't check when I built it was the compression ratio. I'll fish out my compression tester and see what it says when I get a chance.

Yep that's the pump I've got - mounted low down under the bonnet. We hooked a flow meter and pressure gauge up to it and you could see the pressure drop off after a few seconds and the inline fiter empty. It's marketed as an SU replacement so as you'd expect Peter had seen a few on A series engines - his opinion was that it's only good for about 80bhp.

In the next few weeks I'll replace the pump and take it back for final jetting and timing - if it gives the same figures I'll pop up the road to another place (that doesn't 'do' carbs anymore) and do a couple of runs there.

Stuart

[hutch6610]

Don't worry Stuart, i don't think (or ever have thought) you are an idiot.
Slither of rubber could have come from the "o" ring when it was put in - its easy to get it wrong and slice a little off.

Also you seem quite surprised by the figures yourself.
Cams alone from Guy croft - if they were some sort of fast road or race - still could not quite manage it with the standard carb you have.

Do your pistons have flat crowns - by that i mean no raised or domed sections?

Betas - good ones anyway - are / were fast and people don't believe me, quicker than a Ford RS2000, Fiat 131 sport (the 131 boys are adamant they have the quicker car) and quite a few other - even the mighty BMW 323i of circa 1985 can be given a run for its money.

Do you or have you ever run your car on a drag strip to see what sort of standing quarter mile you get (bet you will when you get the fuel delivery sorted)

Compression readings will be interesting - anyway good luck and see what happens.     

[thecolonel]

I found on the Gamma that turning the fuel pressure up to 3.5 psi made it more efficient
on fuel (previously scavenging fuel from second choke) new pump runs at 7psi and filter king
filter/regulator maintains the set 3.5 psi.

Geoff
it's faster than a Beta

[HFStuart]

Nothing spectacular on the compression figures. 165-175 with a slightly less than fit battery. Again pretty much what I'd expect, perhaps even a touch low.

Anyway the pump is due to be delivered this week so I'll put it on at the weekend and see where we go from there.

Styuart

[insayner]

hi stuart this is steve i had a problem with my engine in my spider thought it was down on compression on 3and4 cylinders i had a pair off twin 40s dellorto fitted . i but back the single carb back on to find the compression was ok.I to had fitted the same electric fuel pump to the car .the car run but not very well and had a lack off power.I fitted back the twin 40s had them synchronized even fitted a fuel gauge she runs real well even at the ton the gauge is showing 1.5psi .i think the single weber does require a high fuel pressure.                                                                                                                                 steve.