I bought these SUs off Hitoroku, who bought them off someone else on here and never used them, so they are not 'bolt-on-&-go! One was partially dismantled, so I assume the guy HE bought them off never got them to go, and I'm willing to finally sort them out.

 

They came bolted straight onto the Lynx manifold, and I've always seen plastic spacers in there. The LH picture is off a Datsun with its original plastic spacers, the middle one is off Rob's KE with metal spacers he made up, and the RH photo is of mine currently.

 

So do I need them, or do I just use the two gaskets that were back to back in there, or do I grab some polycarb or nylon and cut a pair, or do I add to SU-Midel's retirement fund and buy a pair.

 

How thick do you reckon they need to be? I have some 4mm polycarb lying around. Do they do anything except keep the head temp from seeping into the carbs?

 

and if anyone has 1&1/4" ram tubes lying around I'd love to know..

..on another slant-

 

this is apparently off a Volvo as used. Did Volvo run SU's like this?? It seems a compact arrangement and is quite tempting as I have to make up linkages etc anyway. I'm going to build an airbox to cover both carbs at once and run a flat panel paper filter.

..and while these questions are popping up, what minimum clearance around the ram tube end do I need??

 

A throat diameter in all directions? More?? Less?? A throat radius??

 

I can move the airbox fore and aft & vertically to make sure a box side is not close to either throat, but I'm a bit squeezed to get the filter face far enough away from the throat entry...

 

Oh- and the Volvo setup can't work on the Lynx, they sit too close together.

i run twin su's on my 4k, on a lynx manifold, and i don't run spacers.

 

 

I don't see the need for them and they will just push the carbys closer to the strut tower.

You're also going to need a heat shield, like the very sexy example above. ^^^^^^^^^^

ooohh.. very nice Smithius- Ok, that's what I'll do complete with the trumpets, but I'll put an airbox on it with a panel filter down the front.

 

mmm.. nice fan too!

 

& I was planning a heatshield squeezed in there somewhere. I know the SU's tend to stick and overflow as well...

My spacers are on there so as to prevent linkages fouling the manifold... other than that I wasn't overly worried.

 

Heatshield would be a good thing too.

 

and I added to SU-midel's retirement fund by buying the spacers (made of aluminium) off them. I can't remember what I paid though.

 

Robert.

Hey Keith

were your hs2's shorter in length than my hs4's?

 

Robert.

Yep, you are right!

 

85mm compared to your 105mm, so more room for the airbox. I'm trying to maximise the distance between the trumpet and the filter face. I'd like a lid over the filter for a cold air intake, but that might not be possible.

I have alloy spacers on my SU setup. Mainly as the carb's are 1 3/4", and the spacers are to help blend them into the Lynx manifold.

 

If you run a heatshield, make it a two piece setup. Give you more space to work around the carbs before you bolt in the main heatshield.

yeah that heat shield made a huge difference, but it was a pain to make and even harder to fit.

 

and the thermo fan is awsome, allows the motor to rev alot easier.

Yeh that heat shield is nice. I need one for my dellortos.

 

The carb spacers made of phenolic resin are just another heat insulator, slow the heat conduction from the head to the carbs.

Yeah I was just about to add that. I'm not sure I understand why you'd use alloy spacers, it kind of defeats the purpose, unless you're using it to narrow down diameter. Even then maybe there are better ways to do it?

 

The Datsun spacers, which I'm using, are definitely for heat insulation, and have rubber on each side for a bit of sealing.

I have alloy spacers because thats what was available at the time, and they were needed for throttle lever clearance...

 

I had a hell of a time getting vac leaks fixed too.

 

Robert.