Venturi Sleeves into grey strombergs

[choppedfan]

Ok I'm running twin strombergs that I setup and they are running fine, smaller main jets and they respond well

Some might have seen elsewhere I now am setting up a set of triples, I've stripped cleaned and polished the carbs, got new gaskets, new smaller jets are on the way as I type this and from all I've researched venturi sleeves that suit 350 Holley's are a must have when running triples.

I've got two sets so it gives me one to stuff up trying to work out how the bloody things are actually fitted into the main body of the stromberg venturi. Put simply everyone has said Oh yeah just fit the venturi sleeves and all will be fine, but nobody has said which way they are fitted in ie: from the top or from the bottom above the main body insulating spacer Also read they have to be araldited in and filed but again, how much and from where.

I've read Harv's excellent Stromberg research and while its absolutely full of good info I couldn't find anywhere about the actual fitting of the Venturi Sleeves. So rather than make a dumb mistake I'd rather ask a stupid question

Could anyone please tell me how to fit these sleeves,
I want to have these set up so when I change the twins over for the triples they'll just need a final tune up on the motor

Mick

[Harv]

Mick,

One of the FE/FC guys has been playing with them and sent me a detailed description of how he fitted them, but being a dumbarse I deleted the PM .

From memory, remove the air horn, and fit from the top. The little flange on top of the 350 Holley restrictors will prevent them from "falling down" the throat. You will need to squeeze them to get them to a small enough diameter to fit the Strommie throat - gently with multigrips. The gap in the restrictor goes over the booster venturi. You will need to file back the gap so that as the restrictor is squeezed, it still has enough gap to clear the booster. The filed gap remains in the finished product (i.e. there is a vertical strip of venturi wall under the booster that is not covered by the restrictor). Epoxy in place.

Probably other ways to fit as well - more than one way to skin a cat.

Cheers,
Harv.

[choppedfan]

Cheers Harv,

You've made an old man very happy, thats exactly what I needed to know

Thanks mate
Mick

[parisian62]

Hi Mick,

I'm hopefully picking mine up from Dr Terry tomorrow. I will ask but it looks like Harv has the answer. You can also PM Dr Terry here on the forum too.

Stewart

[choppedfan]

Hi Mick,

I'm hopefully picking mine up from Dr Terry tomorrow. I will ask but it looks like Harv has the answer. You can also PM Dr Terry here on the forum too.

Stewart

Stewart if you are talking to Terry tomorrow any other tips are welcome in particular if he could give me a rough idea of how much I have to file off.

Cheers mate
Mick

[Stygian]

Nigel from Xtreme Fuel Systems in Campbelltown did mine, but didn't use the Holley units. He had a whole big draw full of venturi sleeves and he picked out three that clicked into place without gluing.

[Thommo]

from all I've researched venturi sleeves that suit 350 Holley's are a must have when running triples.

Gday Mick
There is way to run triples without venturi restrictors.
The Crupi brothers both run a progressive linkage set-ups.
The engine use's a single carb at low revs,
then the other two carbs join the party when the throttle is squeezed.

I couldn't find a good pic of this set up among my Nationals photo's,
But I'm sure someone will have a clear pic of them.

Cheers
Jeff

[Harv]

Thommo,

Theres a pic of a set of triples with progressive linkage on pages 105 and 106 of the Carb guide (in amongst all the other Stromberg porn ). Not sure if it's the Crupi brothers car though.

I love the idea of progressive linkages - lots of thinking to put them together and tune, but massive CFM when they are all at WOT. Cool old-school engineering at it's best .

Cheers,
Harv.

[choppedfan]

Thanks guys,

I've now fitted the venturi sleeves and my new jets have arrived nearly there now.

Mick

[Stygian]

Thanks guys,

I've now fitted the venturi sleeves and my new jets have arrived nearly there now.

Mick

What size jets are you fitting, if you don't mind me asking Mick?

By the way, you can get variable main jets. A club member turned up to the Xmas party this year with these fitted to his twin Stromberg setup. He was telling me you can really get the stochiometric ratio sorted properly when using these. Have you seen on eBay that Sonic Injection is now making alloy fuel injection manifolds for the grey?

[choppedfan]

I got two sets 46 and 44, with triples on a linked system not progresive I'm trying not to "over fuel" the motor, I've read plenty of different setups so we'll see how this goes

I did look at variable jets and appreciate the fine tuning that could be achieved but I guess I'd rather go with fixed size main jets at least I know if its too rich/too lean and how it runs. I know that engines that appear to be built to the same specs can perform differently, so what works with one may not work for another.

And I do like to tinker

Mick

[Stygian]

I love the idea of progressive linkages - lots of thinking to put them together and tune, but massive CFM when they are all at WOT. Cool old-school engineering at it's best .
Cheers,
Harv.

Arguably, installing triples on a grey is not really about the flow, but the fuel/air mix distribution. On the stock single carb setup in a grey, most of the mix ends up in cylinders 3 and 4, with cylinders 1, 2, 5 and 6 missing out. Running triples helps even out the distribution, which incrementally helps with power, but more importantly it helps to reduce pre-detonation in high compression engines. Given that 10:1 static compression is getting pretty high for a street grey (circuit greys run 12.5:1), even distribution is quite desirable.

Mick, let us know how you go field testing those jet sizes... many years ago I heard the rule of "48s for twins, 46s for triples", but the guy who rebuilt my triples was firmly against going any smaller than 48s.

[choppedfan]

I love the idea of progressive linkages - lots of thinking to put them together and tune, but massive CFM when they are all at WOT. Cool old-school engineering at it's best .
Cheers,
Harv.

Arguably, installing triples on a grey is not really about the flow, but the fuel/air mix distribution. On the stock single carb setup in a grey, most of the mix ends up in cylinders 3 and 4, with cylinders 1, 2, 5 and 6 missing out. Running triples helps even out the distribution, which incrementally helps with power, but more importantly it helps to reduce pre-detonation in high compression engines. Given that 10:1 static compression is getting pretty high for a street grey (circuit greys run 12.5:1), even distribution is quite desirable.

Mick, let us know how you go field testing those jet sizes... many years ago I heard the rule of "48s for twins, 46s for triples", but the guy who rebuilt my triples was firmly against going any smaller than 48s.

Just thinking back, wasn't it Eric who built your grey?? I heard he has been scaling back a bit and sold his red 39 I did have his number somewhere if you have it can you pm it to me I'd like to give him a ring to see how he's going

Oh yeah I'll get back to you and let you know how it performs with the smaller jets, I'm off to Perth next week for a holiday (xmas rush has come and gone) hopefully it won't be full of tourists from NSW

Mick

[Stygian]

Eric did indeed build my grey, but he didn't do the carbs. Yes, he has sold his cars (not sure about the So Cal Special) because he felt that he's had his fun with them and it was someone else's turn. I'll PM you his numbers.
I'm off to Perth soon too for a conference at UWA, so no rush about the jet size feedback.