219 replies to this topic

[LC-GTR-1969]

Gday everyone,

 

I have just picked up a set of 2 inch SUs and a warnerford manifold to play with on my 202... I am currently running webers but I wouldn't mind trying the SUs to compare back to back...

 

Thanks very much to 'limo' from this forum for supplying them!

 

I will be rebuilding the SUs and just have a few questions;

 

a) Where is the best place to get kits for them at a reasonable price?

 

What needle would be a good starting point? engine is 202, 9 port head, and 266@50" cam. My experience with the webers was that my engine needed fatter jetting than most others out there. I run 2 steps richer mains than most in the webers, if that accounts for anything...

 

c) What is the clearance like on an lc/lj? I have heard that they can hit the bonnet?

 

Cheers, kind regards

 

[jd lj]

My mate is a su fiend and had run 2"su's with just about every manifold and recently told me that he's never had a problem with clearance.

The original jaguar needles fitted to 2" su's are apparently not suitable for a 202, I'll try to find out which ones are, "UL" have been mentioned but I can't remember if they were the correct ones or not.

When you say that you had larger jets than most in your webers what were the jetting specs, just curious. They were 45dcoe53 and 55's weren't they. Some models will also require bigger idle jets due to the progression holes pattern. That model weber has quite large diameter progression holes.

JD

[LC-GTR-1969]

cheers for reply...

 

Webers are 55s, and it was mainly the main jets where it wanted the larger sizes. I run 165 main and 200 airs... although just to clarify, this engine made most power on the rich side when being dynod, AFR was at 11.7 which made the most hp. Detonation was not observed. I was convinced that something must be astray, and possible was/is, however the track confirmed that the 165s were the best as mph was the highest with this jetting. When I leaned off to 160, 200 airs, I drop 1 mph... 155, 200 airs, down 2 mph and so on. 

 

If I was bothered I would throw it back on the dyno and check the EGTs of each primary pipe to try to determine if a carb throat was overfueling one or two cylinders (for example) and causing the rich readings on the AFR. 

 

Fun and games lol

[LC-GTR-1969]

Thanks mate...

 

I just looked up SU Midel and it turns out its very close to home, and I know the place... A forum member works there and he helped me out with some weber jets (nice bloke)- I didnt know the place dealt with su carbs, just knew it was a parts supplier.

 

Ill drop past in the next few days and get some kits.

 

Will be interesting to compare the webers back to back. I love my webers... Car runs great with them, so really I am just experimenting and playing around. 

[caterham2]

Check that you have .125" jets in carbs. If so from Midel obtain AUD1370 Needles (UH) (L) is number on my invoice from them. These should be close, no oil in dashpots in mine and around 250HP. Clearance issues may require a change of float bowl angle, Midel have them, I also have a set of VGC horizontal  ones if you need them. These would go on a short manifold, not one like mine. See picture. Now running a very large conventional battery without issues.

Check that you have .125" jets in carbs. If so from Midel obtain AUD1370 Needles (UH) (L) is number on my invoice from them. These should be close, no oil in dashpots in mine and around 250HP. Clearance issues may require a change of float bowl angle, Midel have them, I also have a set of VGC horizontal  ones if you need them. These would go on a short manifold, not one like mine. See picture

Attached Files

•  torana engine bay.jpg   381.04K   32 downloads

[LC-GTR-1969]

Check that you have .125" jets in carbs. If so from Midel obtain AUD1370 Needles (UH) (L) is number on my invoice from them. These should be close, no oil in dashpots in mine and around 250HP. Clearance issues may require a change of float bowl angle, Midel have them, I also have a set of VGC horizontal  ones if you need them. These would go on a short manifold, not one like mine. See picture. Now running a very large conventional battery without issues.

Check that you have .125" jets in carbs. If so from Midel obtain AUD1370 Needles (UH) (L) is number on my invoice from them. These should be close, no oil in dashpots in mine and around 250HP. Clearance issues may require a change of float bowl angle, Midel have them, I also have a set of VGC horizontal  ones if you need them. These would go on a short manifold, not one like mine. See picture

Cheers mate....

 

Hp specs similar to mine- what cam specs are you running? Also, not quite sure what you mean by the float bowl clearance- can you elaborate? 

 

Cheers mate

[jd lj]

I've been told that the Armours manifold fits ok, maybe there's more than one model of manifold.

 

What size chokes ,auxilaries and emulsion tubes were you running in the webers.

 

It'll be interesting to compare the results.

[LC-GTR-1969]

I've been told that the Armours manifold fits ok, maybe there's more than one model of manifold.

 

What size chokes ,auxilaries and emulsion tubes were you running in the webers.

 

It'll be interesting to compare the results.

40mm chokes, 5 aux. and f2 emulsions

[caterham2]

LC, Ian Tate and Clive from Clive Cams cooked up this cam spec one day over a cup of coffee as an experiment. It is  the specs that the HDT works V8 race cars ran in "the day" in group C.  I don,t know the specs but I am sure they can be found, however it's pretty grumpy under about 3000rpm, idles best at around 1500 rpm, pulls real hard upwards of 4000 rpm but is very torquey and responsive with 2'' Su setup just about anywhere in the range. Re the float bowl angle, SU come in various configurations to suit the angle that the manifold leaves the head. The std XU1 factory one is "level", mine has an upward sweep and some additional length as well, requiring a change of float bowls to restore the floats to a level situation. If you look at the photo you will see this. My carbs were originally from a Jaguar E type engine and had bowls on the same axis as the carb body. These can be changed if required.. Hope this helps.

Edited by caterham2, 09 February 2016 - 10:24 PM.

[warrenm]

I'll have a look at my petrol needles in the morning.

I use an Armours manifold & the front carb definitely touches the bonnet if using a rubber engine mount, mines solid on the left now. You should be ok with the Warnerford, but some blue tac on the carb & close the bonnet carefully.

As mentioned HS8 or HD8?

 P1020112 (600 x 450).jpg   76.23K   15 downloads

HS8 on the left & HD8 on the right.

 

 P1020113 (600 x 450).jpg   75.76K   13 downloads

 The fuel bowl angles were mentioned above.

[jd lj]

Dude, pay attention to what people are posting. 
I specifically said the FX/FJ armours, because they dont fit. 

That's fine Bomber, I know what you posted, but you didn't mention that there's a different armours manifold that will fit or how to visually distinguish one from the other.

I think with the su's you'll possibly find that the lower rev range will be improved over the webers with 40mm chokes. The su's should work better over a larger rev range than the webers which you have to basically pick a particular rev range and work to that.

I did some calculations a while ago to compare the cross sectional area of different throat sizes of cd carbs compared to weber choke sizes and 2" su's were just slightly more than webers with 36mm chokes, but as old Johno has said one large hole flows more than 2 smaller holes of the same area.

[LC-GTR-1969]

LC, Ian Tate and Clive from Clive Cams cooked up this cam spec one day over a cup of coffee as an experiment. It is  the specs that the HDT works V8 race cars ran in "the day" in group C.  

 

Sounds similar to the story in mine... Mine is an old Wade cam- Clive ground it when still working at Wade and had the same story about being very similar to the HDT works race cars in group C etc. So chances are we have either the same cam or very similar. 

 

My cam specs are certainly experimental. You cannot find any cam with the same specs these days. Mainly as the lobe seperation has been pulled back a lot, which makes for very grumpy below 3000, but very, very strong between 4000 and 6500rpm. 

 

Still, I think more modern cams would make more peak hp but cant be bothered changing the cam at this stage, and I do like it. 

[LC-GTR-1969]

I'll have a look at my petrol needles in the morning.

I use an Armours manifold & the front carb definitely touches the bonnet if using a rubber engine mount, mines solid on the left now. You should be ok with the Warnerford, but some blue tac on the carb & close the bonnet carefully.

As mentioned HS8 or HD8?

P1020112 (600 x 450).jpg

HS8 on the left & HD8 on the right.

 

P1020113 (600 x 450).jpg

 The fuel bowl angles were mentioned above.

 

Cheers...

 

It would appear I have HS8s based from your pic...

 

thanks heaps for the advice!

[warrenm]

It's been 9 or 10 years since mine raced on petrol, but I used UM, UX & UP needles with a 250° cam. HS8's will be fine if you are if your going to stay with petrol type fuels, you may get away with E85 but the float setup isn't that great with Alky. The HD8 has a brass float that applies better force on the needle & seat & the fuel passage is larger from the bowl to the fuel metering needles. You may find that you won't have to run as rich with the Su's as you did with the Weber, I make best power at 13.2: afr which is around 1100°f egt 

Edited by warrenm, 10 February 2016 - 08:10 AM.

[LC-GTR-1969]

Cheers Warren, fantastic advice...

 

Just another question, what kind of fuel pressure do these like?

 

In the webers I run just under 3psi- regulated and holley blue pump. Much more pressure and it blows past the needle apparently

[warrenm]

With the HS8 about 3-4 psi, otherwise the same problem as weber.

[LC-GTR-1969]

Cheers, I will try 3psi and go from there...

 

It will be interesting to see the results. I imagine peak hp will be very similar, or maybe even a little less with the SUs but as JD said, I think the SUs will have better airspeed and thus better low down torque than the webers with the oversize/big chokes.

 

It's entirely possible that the SUs may make more peak hp though, not sure... Only time will tell...

 

It may take a while, but I once i have them all rebuilt, installed and tuned, I will run it at the track and compare timecard details and report back. As I said, it may take a while as I am very busy and hardly have time to do much of anything these days.

 

Whats the best cold starting method? I wont be using a choke... with the webers, I just used the pump shot to start it and first kick off she went, even after weeks without being run. In all honesty, my webers really are running well at the moment, but I am still curious to see the back to back comparison.

[jd lj]

The su's should use a choke (cold start mechanism in the weber world), if it starts well without one the needles are supposedly too rich.

[caterham2]

You won't have a snowballs chance in hell without 3 chokes working

[LC-GTR-1969]

You won't have a snowballs chance in hell without 3 chokes working

 

hmmm... that will be very annoying. 

 

Aero start here I come LOL...

You won't have a snowballs chance in hell without 3 chokes working in 2 inch SUs

 

Another reason I love webers!

[jd lj]

You'll probably find it will idle a bit rougher with su's. I'm rebuilding some webers for a friend's RT CHARGER and he's fitted 2" su's in the meantime and now it sounds like a holden red motor. But webers are known to smooth out the idle to a degree.

On this charger he found a large decrease in power with the su's over the webers, but keep in mind that neither set of carbs had been tuned to his engine, they were just bolted on as they were and used.

From the comparisons that I've seen between su's and webers, the webers are a bit more responsive, presumably due to having a smaller plenum of air to move when the throttles are opened rapidly.

[LC-GTR-1969]

You'll probably find it will idle a bit rougher with su's. 
 

Yes, I am expecting this, especially with the size of the cam I am using. My engine idles remarkably well for the cam specs. SUd 6s that I have seen seem to need a higher idle, like 12-1300rpm

 

My engine with webers can idle smooth and well at 600-650rpm with a 266@50" cam and over 100 degrees of overlap (cam is not ideal but the webers do smooth it out and settle it down somewhat). In saying that, I have the idle set at 850rpm now as it gives some buffer if it starts to fuel up in heavy traffic. Still good considering.

 

On this charger he found a large decrease in power with the su's over the webers, but keep in mind that neither set of carbs had been tuned to his engine, they were just bolted on as they were and used.
 

This wouldn't suprise me with a 265 as from memory they have individual runners, as opposed to the red 6/ 9 port holden 6s, where the port is shared.

 

However, in a holden 6 running a 9 port, I think some of the weber advantage is neutralised to a degree. Its very possible peak hp will be a little lower with the SUs, but in all honesty, I think peak numbers will be similar/ comparable at least.