Drive belt water inlet adaptors

[Lee]

I am using a Danny Bee drive belt with remote electric water pump, and want to maximise the water flow into the engine.
The water pipes from the pump attach to the drive belt cover as shown in picture below. The previous owner had 3/4 NPT threaded fasteners in the water inlet holes, but I don't like that idea, and want to use proper mounting adaptors, at the maximum size I can find. The hole into the block is more like 22mm (I couldn't measure it properly)
3/4 NPT internal diameter is about 3/4"? (I'm not used to NPT) which is about 19mm. The biggest proper adaptor I can find is from Meziere (shown below), but that is only #12 which is therefore about 17mm.
Does anyone know of any adaptors for the SBF which will allow me to fit something bigger without the restriction? It seems a bit daft having 1.5" pipe from the radiator to then try and force it in 2 x 3/4" (or even smaller) holes.
Area of 1.5" diameter is 1.77sq.in. Area of 2 x 3/4" holes is 0.88 sq.in. Area of 2 22mm holes is 1.18 sq.in. Area of 2 x 1" holes is 1.57 sq.in.

 

[Jac Mac]

Lee,

Before you change the size of the fittings why not conduct a quick experiment by hooking the pump up off the car into a bucket of water and time how long it takes to empty it with and without the 3/4" fittings. The
pump may already have internal restrictions that limit the flow.

Jac Mac

 

[David Briggs]

I have the Danny Bee belt drive and a Mezier Electric water pump, it works just fine. You don't need to re-engineer the thing, you can find some other way to spend your time!

 

[Lee]

Thanks for the guidance so far. Not sure I can test the pump. Because it is an electric, water flows through it even if it is switched off. I don't want to reengineer. I just wondered if there was any way of avoiding the restriction at the inlet of the engine. Happy with the restriction out of the heads, which would act to increase pressure in the engine, but restriction into the block would act to create suction through the engine rather than pushing through the engine if that makes any sense. The pump is located at the front of the car, after the radiator.

So anyone know of any bigger inlets?

Thanks

 

[Jac Mac]

Lee,

As long as the outlets from the heads are smaller than the inlets [3/4"] then there should be no problem. Race motors that run a restrictor instead of a t/stat usually have a single opening of approx 3/4".

With your electric pump to you run a t/stat? If so how does the water circulate before the t/stat opens?

Jac Mac

 

[Lee]

Jac Mac. Now we're cooking. No t'stat. I should have mentioned earlier. Now I can see the confusion. I should have said I am running Yates heads with -16 outlets.
Therefore the -12 or 3/4NPT inlets are the narrowest part of the system.

So from the pump, there is 1.5" pipe through cockpit. Then splits into 2 pipes, possibly 1.25" each. Then these go to the block. The 2 of -16 outlets join together to 1 pipe 1.5" into header tank. Outlet on header tank is also 1.5" which then runs into other pipe through cockpit which is 1.75" running back to 1.75" inlet on radiator. 1.5" oulet on radiator with short run to pump.

Pump controls temperature by running faster or slower as necessary, with temperature probe in head outlet.

I think I am happy about the flow through 2 of -12, but the higher pressure will be before the block, rather than IN the head/block. Artificially restricting the head outlets seems a backward step, so how to open up the inlets?

 

[Jac Mac]

Lee,

The instructions that come with any of the SVO Alloy heads say to use a 3/4"-14 pipe thread & -12 fitting at the front of the cyl heads . Your -16 fittings are to large by the sound of it.

To build a bit of pump pressure in the block/heads you may be able to sleeve the 'new' -12 fittings down to approx 11/16" with a couple of piece's of alloy tube if required , but that may not be reqd with your sytem.

Jac Mac

 

[Lee]

Thanks Jac Mac
Those -16 fittings are not moving. They are definitely in for keeps, so it looks like I will have to restrict them somehow. I want a little pressure in there relative to elsewhere otherwise the bleeds at the back of the heads won't work.

Still seems strange why there is a need for 1.5 or 1.75 pipe anywhere in the system when there is a 2 of -12 restriction at the inlet to the block and at the outlet from the heads.

Just thinking about it, the heat in the heads will create additional pressure, or have I got my high school physics the wrong way round?

Thanks again

 

[Jac Mac]

Lee,

The bleeds are really only to allow any air or steam pockets to escape rather than become entrapped in the water jackets & cause an air lock. The majority of the coolant flows along the block up thru the rear of the block/head & back to the front of the head & exit.

Your High School physics are serving you well. If I had my way the coolant would be flowing in the opposite direction, but I have not got time for that now!!

Jac Mac.

 

[Lee]

Reverse water flow (not reverse rotation)

Jac Mac, I think you've done it again. Why don't I just use reverse flow? Easy plumbing with the electric remote pump. Similar to the ch**y LT1. That would solve the small inlets/ large outlets issue, by making it into large inlets/small outlets.
The bleed I was only planning on a -3 line.

What problems would reverse flow bring into the equation?

 

[Jac Mac]

Re: Reverse water flow (not reverse rotation)

Lee,

Inthe Gt40 application it could bring a few extras due to the coolant hose's running down from motor then up to radiator. Also I believe the SH##? has done a lot of development in the direction the coolant flows from head to block.

Do you have access to Circle Track back issues ( 1980>>) ? If so I will check issues that had several articles by 'Smokey' for you to check out.

Jac Mac

 

[Lee]

I was going to mention that certain Mr. Yunick, but replaced the reference to him with the reference to the LT1.
I did read up on some of what he did quite a while ago, but can't remember any of the detail. Did a quick search on google just now which didn't bring much up.
I guessed bledding may be more difficult, but with the bleed at the back of the engine, (to the top of the swirlpot?), and no thermostat or heater circuit, once bled, it shouldn't be too much of an issue, should it?
Any links to Smokey's articles greatly appreciated.

 

[Ron McCall]

Lee,

I spoke in length with the tech people at Meziere about my application.( 9.2" deck SVO w/Yates C3 heads) I ended up with their 55GPM remote mount pump wth one 1 1/2" inlet and two -12 outlets.It mounted perfectly in the front near the radiator.I ran -12 fittings out of the heads into a "Y" fitting to a 1 1/2" fitting through a 1 1/2 " pipe to the radiator .the two -12s from the pump attach directly to the front of the block.
They say this should work fine even for a track car. We'll see.

 

[Lee]

Ron, that sounds like an identical combo to mine except the make of pump.
If I had -12 oulets on the heads I would be fine, so the options are either restrict the outlets, or run with reverse flow. I like the idea of reverse flow if there are no major downsides to it. Keeps the heads cooler - better for avoiding detonation, so can run higher CR. Also keeps block warmer - better for piston wear apparently.
Just need more info.
All the best

 

[Jac Mac]

Hi Lee,

Circle Track-January & June 1990. One major requirement seems to be Propylene Glycol as a coolant to avoid boiling . The only hands on experience I have had was with a V8 that we inverted for use in an aircraft and pumped the coolant into the heads & took it out the core plug on the side's of the block. However in that instance the" heat rise's" feature was working with us
and we were able to use water alone as coolant during testing.

Meca Development, Inc -- was the outfit involved. Address in article--255 Route 41, Dept CT-01 Sharon, CT 06069. ( Remember this is 1990 info )

Jac Mac.

 

[Russ Noble]

As I understand it glycol does have a higher boiling point but transfers much less heat causing higher engine temperatures anyway. It pays not to go over 30% glycol otherwise there is the possibility of localised hot spots. Much better instead, I think, to go with some of the 20 to 30 psi competition caps that are available and maybe some water wetter as well. Just MHO.

Cheers

 

[Lee]

Managed to do a bit more searching and it sounds like there are a few more issues with flow through the heads, cracking heads due to temperature 'shock' etc. It appears that Evans Cooling (new name for Meca development) have been trying to sue GM for many years (presumably for the reverse flow LT1), but most of their site relates to conventional flow (I couldn't find any on it relating to reverse flow)

So I will use conventional flow direction, and place a restriction at the outlets of the heads.

 

[Jac Mac]

Lee,

Probably a wise move. The basic Meca[Evans] system in using (PG)Propylene Glycol flowed in the conventional direction and was intended to run at atmospheric pressure with a condenser to remove any water from the system.They apparently have/had other more advanced system's with the reverse flow.
As PG boils @369 deg F the running temp was supposed to be higher for more power. The PG had to be 100% inhibited as any water or other fluid with a lower boiling point would allow nucleate boiling and temp spikes at critical areas around the combustion chamber.

It was interesting to note that in a well developed small block, Smokey reckoned there was about 15 HP available from reverse cooling which is a lot in a class where you are governed by rule's, but on an individual case like yours is it worth the effort??

Jac Mac

 

[Lynn Larsen]

Lee,

You might want to give this a look. High dollar NASCAR type piece, but I'd bet they'd have a solution for you.

Stewart ProSeries Windsor Waterpump

Lynn

 

[David Briggs]

Hi Lee, I am curious as to why you went with the remote pump, Mezier makes an engine fitted pump that works very well with that belt drive.
The pump that I am using only flows 35/GPH and has no problem keeping the engine cool even in traffic on days where the temp is 100 plus(farenhight).
water temp stays at about 180 even on the track.