Weber Recipe?

[roy53]

Totally agree Neil

These guys seem to know their way around weber's and have so far proved good.

The race engines are looking for max power so not lowdown running but having watched them for hours work i would hope they could help.

Have had cars with miss fires that don't show on rolling roads so not always the way to go.

Roy

[iani]

2 hours ago, roy53 said:

Totally agree Neil

These guys seem to know their way around weber's and have so far proved good.

The race engines are looking for max power so not lowdown running but having watched them for hours work i would hope they could help.

Have had cars with miss fires that don't show on rolling roads so not always the way to go.

Roy

I have triple 40's on my 2.5l GT6 running a 300 cam from Tony Lindsey-Dean. I had my DCOEs set up on Northampton Motorsport's rolling road and the engine is delivering 192bhp, I had set a limit of 6k RPM and it was still climbing when they backed off. My carbs perform very well but the transition "stumble" is definitely there, if you accelerate gently is is a very slight stumble, floor it and it is annoying. I doubt you'd notice on a track as you won't be dipping below 2.5k and it doesn't happen above that, the RR operator I worked with was adamant that it can't be removed completely.

Please PM me the details of the RR you use, I'd be interested to get their view as to whether I should be able to improve my transition or not.

[Tim D.]

Iani,

Sounds like the classic problem with dcoes.. when you get it sorted make sure you check drivabilty and see an AFR trace for some runs around transition. It is a common trick to make the idle circuit really rich to cover over the transition lean situation. Works well for a while and then you end up with fouled plugs and bad Mpg. 

Tim

[unclepete]

Another quote from the Doctor!

"I would think  you need  about  32  degrees  max advance , with  static of  12 , that  necessitates  a distributor  that will  yield 20  degrees, so it  would  have a 10  degree  cam in it"

He's going to analyse my 22D dizzy and sort me out weights, springs and limit cam to suit.

I would love to run my dizzy on one of those old school "Sun" machines! 

[roy53]

123 distributor with bluetooth. These can be setup on the rollers via a mobile phone as it progresses through the rev range.

Roy

 

Ian pm sent

[BlueTR3A-5EKT]

3 hours ago, Tim D. said:

Iani,

Sounds like the classic problem with dcoes.. when you get it sorted make sure you check drivabilty and see an AFR trace for some runs around transition. It is a common trick to make the idle circuit really rich to cover over the transition lean situation. Works well for a while and then you end up with fouled plugs and bad Mpg. 

Tim

Continuous over fuelling is said to accelerate wear of pistons, rings and bores due to bore wash also known as fuel wash.    The fuel washes the oil/lubricant from the bores.

[Tom Fremont]

Stumble often can be cleared up by fitting closed pump bypasses. I did this in the last century and have seen this move make a big difference in other TR6 engines with DCOEs as well. I use a piece of rubber fuel line to remove and replace these once loosened, screwdriver starting and finishing the process. Pretty easy switch to do.

F7 emulsion tubes have also worked well for mine; these bring the main system in at lower rpm.

My brass throttle shaft 40s have served on my driver for over 140K miles now. Here's how it runs today:

A hill climb (of sorts) begins at 2:50 and goes for about a minute. Pretty quiet for a TR at these speeds; hardtop to blame. The Michelin XWX tires sing pleasantly; 2nd set of these now.

It has a fresh engine ready to install when she gets repainted, due after ~ 30 years and 90K miles since the last time. That one is also CP spec but with Carillo rods, Weisco pistons ( removing ~6 lbs off the crankshaft ) and machined to very low 4 decimal place consistency, crank balanced to < 1/4 gram. 

The concourse car has another engine in the works; more on that later.