My HS4 plumbing solution

[fogliner]

Hi Gang.

Just thought I'd post a picture of something I've built to sanitize the plumbing on my HS4's before I install them.
Brass tubes and bar available from your local hobby shop for probably around $12.00.
A little brasso polish and some elbow grease and it should gleam.
I kinda like the look but I may have a biased oppinion since I did build it.

Comments and critisism welcome.

Mark

 

[Mickey Richaud]

Mark, that looks great! How is it stabilized - supported?

 

[fogliner]

Thanks Mickey,Here's a side picture that shows a bit more.

It's just sitting on the bolt now but I plan to put it beneath the nut with a flat washer and lock washer as well.
It's surprisingly stable and strong feeling to me.

 

[Mickey Richaud]

I thought that might have been what you did. Nice job!

 

[Dave_W]

Are you planning/do you need hose clamps on there? I know they run at low fuel pressure, but a gas hose dropping off could be a very real problem.

It does look really nice.

 

[fogliner]

Thanks Dave and Mickey,Yes I have some original clamps I'm saving for the hoses,I know what you mean Dave , I'm actually looking for some flanges to solder onto the ends of the brass tubes which along with the clamps should be pretty secure.Pretty hard to find brass 1/4 and 9/32nds brass flanges though so I may use my original clamps along with those squeeze clamps like the ones that come with fuel filters these days just for extra security.

Mark

 

[Scott_Hower]

Thanks Dave and Mickey,Yes I have some original clamps I'm saving for the hoses,I know what you mean Dave , I'm actually looking for some flanges to solder onto the ends of the brass tubes which along with the clamps should be pretty secure.Pretty hard to find brass 1/4 and 9/32nds brass flanges though so I may use my original clamps along with those squeeze clamps like the ones that come with fuel filters these days just for extra security.

Mark

Looks nice.

Could you flare the ends of the tubing? Or maybe solder a compression egg on the ends.

Only thing I'd be concerned about is heat transfer into the tubing from the head. Are these just vent hoses, or do they supply fuel to the carbs? The mounting studs will get hot and brass is a great conductor.

 

[fogliner]

Good point Scott,and one I hadn't thought of either....The center tube is the fuel jumper between the carbs but only the one tube though.Both other ones are just crankcase and floatbowl ventilation so heat shouldn't bother those ones(?).
I 'm thinking that I could just do a partial flare on the ends or IF I can find some compression Eggs for that size tubing that would be easier than trying to flare them...I think I should only have to worry about the actual fuel line tube though as the other 2 are just vacuum or ambient pressure.
Thanks for pointing that out,I'll be watching for that heat thing now for sure.
We could do with a bit of heat right now mind you, It was -14 C last night and supposed to get close to that again tonight....BRRR.

Take care all

Mark

 

[Hap Waldrop]

Sorry to tell you this, but you have some issues to deal with there, you're feeding fuel to front carb, and then carrying it over to the rear carbs, thats all good, but on the rear carbs you have the vent hooked back into fuel feed at the T-fitting, that will not work, you have to vent the rear float bowl as well as the front. Then on the smog tubes, or vaccuum tubes (whichever you want to call them), you have them hook together, if you don't want PCV, which I don't run on my cars, you need to just simply plug the tubes, and not hook them together, or run the PCV system from that point. I don't know if the hose hooking the two smog tubes matters one way or the other, it just that it is wasted hose, but the rear carb vent issue will have to be changed or your rear carb will presurize thru the jet, the simpliest fix to lose the T fitting and that section of hose and and open that vent back up on the rear float bowl.

Hope this helps.

 

[fogliner]

Thanks for the tips Hap.

I thought that I had it right but I guess not.I need to take the rear floatbowl cover off and check that I'm hooked to the right outlets.Here's the theory...
The top tube should be the floatbowl vent tubes and the tee connector connects that group into my carbon canister and therefore my ARV as it was done on my Hifs and it worked fine on them that way.
The middle tube will (and should) be the jumper for the fuel to the rear carb.
Bottom tube should (and will) be CC ventilation from the sidecover tube up the front of the engine to the two brass vacuum tubes on the carbs so it should be a closed loop I think.
I had the hif's plumbed into the front CC vent tube that way and it seemed to be ok.

Other than the hose connecting issue would there be an issue with heat transfer and possible vapour lock problems with this setup? Just wondering and thanks for taking the time to critique my work.

Mark

 

[Hap Waldrop]

OK, looking a the vacuum/smog/pcv tubes, again, they are right the different routing fooled me in the top pic, I now see they are vent to crankcase. On the float vents, now that I studied it more, both vents on both float lids are blocked and hooked to fuel feed hose, you need on the front float lid, take the one you have hooked on the side now to the hose and hook to the one you don't have the hose hooked to, on the rear , loose the one coming out the side and get rid of it's hose altogether. You would fiquired this out if ever got fuel to it, the front tube would have pour gas out and the rear carb would have filled up thru the jet as it not vented at all, probably ame thing on the fornt as well . On the float lids, study them and look at where the needle seat valve is under the lid (on the rear part of the raised section) on that plane is where fuel feed will always be as it is in the line of the valve, the other will not be, and be a simple vent to air.

If you are ever indoubt on float lids, just take them off and test them by blowing inthe them and working the valve closed, that will tell you everytime, because over there are lots of different flaot lid on these carbs, for example my 67 is totally different than yours.

 

[bob67bgt]

Mark,
Everything looks good to me on the fuel and vent routing for a set of carbs from around 1970 or 71. Nice fab. work! Bob

 

[fogliner]

Yes they are AUD 405's Bob and thanks.I have them set up on my old workmate,I rigged up a spare intake manifold to a plank so I could mock everything up and get it right (in comfort)before I install them. When the Temp gets above the finger numbing numbers its at now I will carry my whole rig to the car and run a jumper hose from my fuel line and try them out beside the car for leaks etc.
I wish I had thought of the workmate rig when I was setting the float levels on the original HIF4's.

I may not own a set of HS's now though I guess so it was time well spent...

I will get the hose routing right for sure!
Now the main question could be whether this will be prone to heat soaking and possible vapour locking but we will see come what may.

Take care all
Mark

 

[fogliner]

An update!
The HS's work great so far,I've installed them and my new crossover/evap piece and can say that everything went well on the startup,and setup.I did get the hoses right and flared the ends on the fuel crossover tube and also double clamped it.
I am amazed at the steady idle that I have now :banana:,I can also stand in the immediate vicinity while it's idleing and not get gassed. .
I took it around the block a few times today and didn't notice a great improvement in acceleration but I'm looking forward to seeing how it does on the hills once I put the plates on it.

Yeehaa,my Visa is yelling at me.."use me,use me".My wife is just giving me that look. :frown:

I may just do a commando run to the insurance broker tommorow. :cowboy:

Take care and drive safely and hopefully I will survive the next week or 2 while I build up some brownie points.
Mark