Rolling road and carb setup

will6440

Member
I’m thinking of taking my car to a local rolling road to get the carbs properly set up and the timing sorted. At the moment it isn’t running brilliantly and is certainly way too rich. It doesn’t start from cold particularly well (warm is fine) and has quite poor hesitation below about 2500rpm.
Just wondering if anyone has any experience of doing this? Planning on using a company called Novatech in Slough who are quoting £80+VAT per hour and estimate the job taking about 2 hours. Is this realistic?
 
From my own experience I had a similar problem bad mixture just couldn’t get it quite right so I decided to rebuild my carb only to find that the bushes had worn down over time causing air to get in, what’s the condition of your carbs? have they ever been removed and rebuilt?
The rolling road sound like a great idea
If you go ahead with it please let us all know how it went.
 
Last edited:
Good to know about the bushes, I was told by the previous owner that he purchased a new set of carbs and fitted them straight on but that they haven't been set up. Besides looking nice and shiny I don't have any evidence (no receipts) to back that statement up. So whilst that might be true i'm going to wait to see what they say when it goes off to the rolling road. I've tentatively booked in for the 25th of October so assuming it happens then (or before) i'll let you all know the outcome. I'm hoping for reasonable figures as all the timing gear was replaced 6 years ago so that shouldn't cause too much power loss alone.
 
Not many places will have SU parts on the shelf, if your carbs are new / refurbed then the service parts side should be OK, but if a change of needles is required then it may not be possible to get the ideal tune.
Check your air filters are clean and the ignition side is all tip top before you go.
Two hours should be ample providing they know their way around a Rover V8 on carbs.
 
Last edited:
Not many places will have SU parts on the shelf, if your carbs are new / refurbed then the service parts side should be OK, but if a change of needles is required then it may not be possible to get the idea tune.
Check your air filters are clean and the ignition side is all tip top before you go.
To hours should be ample providing they know their way around a Rover V8 on carbs.

Are service parts/needles for the SU carbs relatively easy to source? Just wondering if it would be worth me buying them before I go as a fail safe? Also mine has electronic ignition is there something to do with that I should be checking? Excuse the novice questions i'm new to the world of old cars!
 
Yes there is sucarb.co.uk
They will have all the parts but without narrowing down the problem it could be expensive, like cobra said make sure you have good ignition, like new plugs good HT leads good dizzy cap coil, rotor arm, then you will have a great spark, I can recommend power spark if you need such items they provide quality stuff, a shot in the dark here it could be that the timing was not adjusted when they fitted the electric ignition sometimes you need to adjust it, I would not think it was the electric ignition module unless it was fitted incorrectly it has to be fitted very close to the arm with not a big gap but not touching either, ask away any questions we are all learning here not all of us know everything about every subject that’s why we can learn from each other and share information.
 
I am afraid that you cannot buy needles in advance, you have to carry out a run to see how the car is fuelling, however...…….
You could post up your full engine spec on here - capacity, carb type, camshaft, heads, porting ? electronic ign etc and see if anyone has a similar spec and a needle suggestion, then take a punt on a pair.
 
Thanks Ban306 and cobraboy. All good to know. I've spoken to the guy at Novatech and he's booked me in for the 25th of October. He has lots of needles in stock for SU carbs so hopefully if I need replacements he'll have them easily to hand. In the meantime i've just bought a new set of NGK plugs, new HT leads and some new air filters to get the breathing and spark situation as good as I can before it heads off. I'll let you know how I get on!
 
Thanks Ban306 and cobraboy. All good to know. I've spoken to the guy at Novatech and he's booked me in for the 25th of October. He has lots of needles in stock for SU carbs so hopefully if I need replacements he'll have them easily to hand. In the meantime i've just bought a new set of NGK plugs, new HT leads and some new air filters to get the breathing and spark situation as good as I can before it heads off. I'll let you know how I get on!
Will6440 I know Novatech in Slough and can vouch for them . They do a brilliant job but don’t tie them too much on time . If everything goes well two hours will be fine but if an unforeseen problem happens it can take a little longer
 
Will6440 I know Novatech in Slough and can vouch for them . They do a brilliant job but don’t tie them too much on time . If everything goes well two hours will be fine but if an unforeseen problem happens it can take a little longer

That’s really good to know. Probably a basic question but do they do the timing at the same time? I’m concerned that he might do a carb setup but if the timing is out it won’t help much.
 
I can’t speak for a company, but if you have any concerns I would suggest maybe giving them a call to check, but I am sure from there reviews and so many cars they have to deal with they will do there best for you and your p6 and to check the timing on a p6 is not complicated at all and something probably they are used to on other classic cars as required.
 
Rest assured, timing is an essential part of an engine set up and of course will be checked. Are your tappets all correct because if the valves are not opening and closing properly engine can’t be fine tuned. Some cars are more critical than others.
 
Pjim6 I believe they’re all ok and it certainly runs very quietly. I have a receipt for a new cam chain in 2013 although I don’t know if the cam shaft was changed at the same time. I’ll be fitting new spark plugs tomorrow as well as checking the oil level in the carbs as I’ve read this might be a cause of some slow engine speed hesitation that I have.
 
Will6440. Don’t worry , things like carb balance and levels are all checked throughly. They do a really good job .
 
Wherever you go, just tell them before they start, “that they shouldn’t take anything for granted as being set up correctly already”. A good rolling road tuner will then work through methodology. They’ll be checking things like compressions, timing (including validating the TDC pointer is accurate), dwell angle etc, as well as the balance, setup and component selection on the carbs.
 
I am also heading for the rollers on Wednesday to get the Autolite four barrel dialled in. I am hoping that it will add something to the top end, but we will see, as long as I don't have to get a dustpan and brush out I will be pleased.
 
I am also heading for the rollers on Wednesday to get the Autolite four barrel dialled in. I am hoping that it will add something to the top end, but we will see, as long as I don't have to get a dustpan and brush out I will be pleased.

I always admire your P6 Cobra, how did you do the bonnet scoop?
 
Oh Ta.
The scoop is a bought in Cobra scoop riveted on.
I got a price to make an alloy one, but at the time early on in the build it seemed a lot of money.
 
it looks amazing and the wheels the series one v8 just looks like the dogs when you ditch the bumper the lower valance just sticks out and you kinda look at it and say ok so why was there a bumper hiding this masterpiece that was there in the first place
 
Back
Top