SU to efi plumbing question

johndregg · Feb 11, 2015

Could someone identify the coolant connections left to right in the pic for me?
My SU manifold has a different array of pipe work and I'm trying to work out what mods I might need to do to plumb this one in.

jamesmartin · Feb 11, 2015

little one on the right is for throttle body water jacket , on left for heater

johndregg · Feb 11, 2015

I currently have a small diameter pipe from the top of the radiator to the inlet manifold, could I use that as the return from the throttle body heater?

jamesmartin · Feb 11, 2015

you could tee into it you will need that pipe to go to expansion tank efi rad has 2 fittings on rad

johndregg · Feb 11, 2015

I should explain that I'm not using this in a normal way. I'm building an lpg only manifold using a BLOS carb as a bit of an experiment.
Would it do any harm to run the return from the throttle heater into the top of the rad?

johndregg · Feb 12, 2015

My current plumbing from the water pump runs to the heater through a pipe under the inlet manifold, then back into the manifold at the back.
This manifold doesn't have a return from the heater at the back. Where can I run the return from the heater to?
I'm still at the planning stage of this job so thanks for your patience.

johndregg · Feb 12, 2015

This pipe at the back of the water pump, is it send or return?
If it's return, could I plumb the heater like this: front of manifold->lpg reducer->heater->back to water pump?

cooltide · Feb 12, 2015

johndregg said:
This pipe at the back of the water pump, is it send or return?
If it's return, could I plumb the heater like this: front of manifold->lpg reducer->heater->back to water pump?

Yes and yes I think so.

Not sure about throttle heater. Mine is removed and no problem, though I'm not starting up on gas

johndregg · Feb 12, 2015

Any idea if the temp sender in the efi manifold will work the same as the carb one? I mean, do I need to retro fit the one from the SU manifold by using an adaptor or cutting a new thread?

cooltide · Feb 12, 2015

I'd imagine it will give a reading, maybe not the same on the guage

johndregg · Feb 13, 2015

I've been doing a thread search on this site and on google to find an answer for the temp sender issue. Quite a few people have asked the same question but they haven't posted their solution to the problem.
I guess fitting the SU type sender to the efi manifold will work best. Or is there a compatible sender that won't need a new thread cutting?
I cleaned the manifold up a bit.

bolokwe · Feb 27, 2015

jamesmartin said:
you could tee into it you will need that pipe to go to expansion tank efi rad has 2 fittings on rad

There are a some pipes going to Matrix how do we connect them

cooltide · Feb 27, 2015

Botswana! You don't need heat

cooltide · Feb 27, 2015

3/4" Pipe under top hose connection to matrix, from matrix to back of water pump

johndregg · Feb 28, 2015

There are different manifolds. This one is 22mm (3/4"?) pipe to the left of thermostat to the matrix, then from the matrix back to water pump. I'm planning to run my return pipe under the manifold.

cooltide · Feb 28, 2015

johndregg said:
There are different manifolds. This one is 22mm (3/4"?) pipe to the left of thermostat to the matrix, then from the matrix back to water pump. I'm planning to run my return pipe under the manifold.

Sorry, I described hotwire efi type.

johndregg · Mar 2, 2015

Sorted the temp sender issue. Drilled and tapped the EFI hole to accept the sender from a carb defender model.

Murtle · Mar 4, 2015

Hi John, how are you getting on with this? You've seen the picture of my 3.9 EFI, BLOS set-up. is it clear enough what is routed where?

For me it was a case of make it up as I went along to get everything to fit. It's a bit tight in a series engine bay so I put the EFI Plenum cover on back to front for extra clearance. Therefore, my throttle cable, and water pipe system are completely custom.

johndregg · Mar 4, 2015

I'm about ready to do the job. Got all the parts, modded the efi manifold to accept the standard 110 temp sender, RRC efi throttle cable fits both ends.
I'm just debating wether to plumb the vaporiser in before the heater or to keep it parallel as it is now. Cut down on warm up time in the morning.
Should have time to do it at the weekend.

Murtle · Mar 5, 2015

I plumbed everything in series in the end, runs as follows: Water pump, vaporiser, heater, engine.

Much better warm up times, and the heater is a lot hotter.

SU to efi plumbing question

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