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Carbs / Manifold

Started by streetracer75, July 25, 2014, 11:44:38 PM

streetracer75

Since I b]got my 73' GLS the one thing that really surprised me was how quick it is! My original intention was to fit a set od Dellorto to it and a 4-into-1 with bigger exhaust system. However, she goes so well in her stock-setup that I am really reluctant now to mess with the twin Stromberg setup.

My question therefore is can I still fit a 4-into-1 manifold and bigger exhaust while keeping the twin Stromberg's setup?


oldschool

#1
That's right...don't mess with the stock setup unless you're going the 'whole hog'!

By removing the exhaust manifold and fitting extractors you'll immediately lose 3 hp as the strombergs rely on the exhaust manifold 'hot boxes' to bring them up to the correct operating temperature!
You can do David Vizards hot box and carby mods to get 13 more hp providing you have the early strombergs with the mixture screw under the bowl?

A common mod is to fit a bigger twin front pipe and free flow exhaust to the existing 4 into 2 manifold as it's already pretty good.
All you need to do is ream out the manifold twin exits a little to match the bigger front pipe and you'll have a little racer for a fraction of the cost (and fuel consumption) of a twin Dellorto setup.
David also said the stock GLS cam is excellent up to 7000 rpm and only needs to be changed for track use where Avengers can rev up to 9000 rpm!

Here's other easy ways to get more power:
Fit electronic ignition and a 12V sports coil (cheap on eBay)
Remove the holset viscous radiator fan (or fixed fan) and fit a 9" electric one on the engine side of the radiator below the top hose.
Fit a 70 deg C thermostat as Avenger blocks like to run cool!
Advance the static timing to 15 deg if using premium petrol.


Scarlet

The David Vizard mods Ross was talking about.
Have a squiz here.   http://s1340.photobucket.com/user/Catsman1/library/?sort=3&page=1

streetracer75

Quote from: oldschool on July 26, 2014, 11:02:38 AM
That's right...don't mess with the stock setup unless you're going the 'whole hog'!

By removing the exhaust manifold and fitting extractors you'll immediately lose 3 hp as the strombergs rely on the exhaust manifold 'hot boxes' to bring them up to the correct operating temperature!
You can do David Vizards hot box and carby mods to get 13 more hp providing you have the early strombergs with the mixture screw under the bowl?

A common mod is to fit a bigger twin front pipe and free flow exhaust to the existing 4 into 2 manifold as it's already pretty good.
All you need to do is ream out the manifold twin exits a little to match the bigger front pipe and you'll have a little racer for a fraction of the cost (and fuel consumption) of a twin Dellorto setup.
David also said the stock GLS cam is excellent up to 7000 rpm and only needs to be changed for track use where Avengers can rev up to 9000 rpm!

Here's other easy ways to get more power:
Fit electronic ignition and a 12V sports coil (cheap on eBay)
Remove the holset viscous radiator fan (or fixed fan) and fit a 9" electric one on the engine side of the radiator below the top hose.
Fit a 70 deg C thermostat as Avenger blocks like to run cool!
Advance the static timing to 15 deg if using premium petrol.
Hi Mate that's great advice. Its all of those little bits of info and tips that make these forums so valuable. I may look at a twin Dellorto conversion some time down the line but for now am going to stick with the Strombergs and do the exhaust mod you suggest. I just need to find someone who can supply or make a bigger bore exhaust for me. Would you suggest 2"?

I already have Flamethrower electronic ignition module and 0.6ohms sports coil on order. I may now look at fitting an electric fan as well. 

streetracer75

Quote from: Scarlet on July 26, 2014, 08:51:49 PM
The David Vizard mods Ross was talking about.
Have a squiz here.   http://s1340.photobucket.com/user/Catsman1/library/?sort=3&page=1

Ok thanks I will enjoy reading this. What year are these articles from?

oldschool

#5
I reckon fitting bike carbs would be worthwhile...they improve Escorts heaps!
If you fit 45 Dellortos they'll have to be choked back to 32mm for road use anyway, so you might as well fit 32mm bike ones in the first place...see this article....

http://www.classicfordmag.co.uk/files/2011/07/CLF166.bike_.pdf

About the exhaust...I've noticed there's a variation in pipe sizes between models and manufacturers. My Hillman GLS has a larger twin front pipe than my Chrysler GLS...because of the twin carbs maybe?
If your twin front pipe is the larger 'Hillman' one and in good condition it can be re-used.
Take it off and you'll find the inside pipe diameters are greater than the manifold outlet diameters, so just ream/grind out the manifold exits to match as mentioned.
2" is best for racing, 1.75" is fine for road use IMHO. If you shop around you may find a 1.75" front pipe off the shelf? If not pretty easy to get made as only one bend. Then mate it to a single muffler with a 1.75" inlet/outlet.
You won't find a 1.75" tailpipe off the shelf...an exhaust shop can make one using your old one as a pattern.
Then you'll have a great free flow exhaust system without breaking the bank!

streetracer75

Hi I have found someone who can make me a custom S/S system http://www.powerflowexhausts.co.uk/.

They mentioned about fitting a flexible down-pipe as part of the system, so as to reduce stress under any movement. Do you think a flexible down-pipe is good idea?

oldschool

Huh? Flexible downpipes are used on modern front wheel drive cars as the east-west motor pivots against the exhaust and can break it otherwise.
Not needed on Avengers and other north-south motored cars as the exhaust moves with the motor.

streetracer75

Yeah I hadn't heard of flexi-pipe on RWD either. Anyway car is booked in. I will post pics of the system once its fitted. Thanks for your help.

Eldon B

Does Any one recommend any bike carbs  ?

oldschool

http://www.classicfordmag.co.uk/files/2011/07/CLF166.bike_.pdf

The Avenger engine would use similar bike carbs to the Ford Kent one in the article.

streetracer75

Quote from: Eldon B on October 25, 2014, 02:53:54 PM
Does Any one recommend any bike carbs  ?

Somebody recommended Yamaha XJ600 or yzf R1, or Honda cbr600 on another site. People who have done this seem to really rate it over weber etc options?

Paddy75

You'd have to chop the face of the inlet manifold that mates with the standard TC exhaust manifold to get the TC inlet to fit over the branched exhaust 'fold. I've seen this on a rally Avenger.
I have a TC inlet manifold already chopped if you don't want to wreck your original manifold.

If you want to go for a 175CD single, this apparently runs about as well as the TC's, the Lynx crossover manifold to use one set of the Dellortos or Webers seems to be a good upgrade - I guess (only a guess) you'd still keep the torque with the Lynx.

Just don't go Weber downdraught, seen them, 'wash the liners' (fuel droplet size way too big) on a MK1 1600 to the point where a re-built engine with 3k miles on it needs re-ringed and is cranking at cold like a washing machine on fast spin. Another job on the cheap I'll likely get from an Avenger owner.

Abroad and thinkin' of avenger