WRAY T96 SUPERCHARGER refurb and install

[EK283]

All well said guys,

You have to remember 138 CI stock, Not much bigger than a lawnmower these days !!!

Power to weight ratio as Harv has mentioned will be the test, although quick shifting a column 3 speed will limit that.

More ponies more bucks and more bangs especially with motors that were never designed to be squeezed.

A good result in my books !

Regards Greg

[ardiesse]

(scratches head . . .)

Taxable horsepower. Hmm. That, I thought, was a calculated figure, based on bore and stroke.

Wikipedia to the rescue. RAC taxable horsepower = (bore/in)^2 x (cylinders)/2.5 . A 132.5 grey gives 9x6/2.5 = 21.6 .

SAE gross power (which is 75 bhp in the case of a 138) is measured on a test engine minus water pump, fan, and generator, and sometimes using long-tube headers instead of the original exhaust manifold. So it will be a very optimistic figure compared with a production engine, and then you have to take away drivetrain losses.

[D-MAN]

Awesome result made all the better in my books because you are using a period correct supercharger
Great to see it up and running

[Harv]

SAE gross power (which is 75 bhp in the case of a 138) is measured on a test engine minus water pump, fan, and generator, and sometimes using long-tube headers instead of the original exhaust manifold. So it will be a very optimistic figure compared with a production engine, and then you have to take away drivetrain losses.

The issue I guess is that the Workshop Manuals specify gross power, whereas the dyno measures nett. Thinking aloud, a gennie takes around 1 pony for every 25 amps. With the Lucas sparkometer sitting on the 20A limit, this is say 1hp (?). The water pump on a Chev pulls 8-20 ponies (according to Moroso), so say 12 horses for the smaller grey pump. Say another 10 for the fan (I made the number up). Maybe 25 ponies difference total in the anciliaries. Cars tested in the late 70's suffered more as they ran breeze and ease as ancilliaries. Tube headers (if they were used for the gross test) would help a little, but the head itself is the big bottleneck on a grey... headers alone sound good but make little difference.

So perhaps the 75BHP gross in the workshop manual is really 50BHP nett, add 30% driveline loss and you get 35 ponies at the treads on a grey.

Cheers,
Harv

[FJWALLY]

Yeah I got that stock figure wrong - based on a few guys who have gone to the trouble to put their greys(mostly FE) on the dyno before mods they were getting low 30's at wheels so yes a jump from low thirties to high 90's is a BIG jump by a mild cam and a bit of wind.

I have to spend some time behind the wheel now and sort through some of the drivability issues - it has a crap idle and is stalling out so may need a couple more rpm on idle screw.

The right foot is pretty sensitive so may explore some different linkage options to smooth that out.

It did have a strange burnt rubber smell a couple of times on the drive back and a funny squealing noise - might have to just live with that

I have no doubt that now bitten there will be further mods to the engine - I think I will be getting to know the Dynomotive guys really well as they have a Magnussen blower that I want on my FJ and a couple of the guys including the mechanic that did the springs has an EK in his garage and a very rare John Bowe Dunnydoor that would be worth a pretty penny.

As a word of warning when they did do the head work they found the springs were the wrong springs - valve clearance was all over the place - so beware Top Torque Nunawading for engine build's.

Going to bed it all in now and tinker and then maybe have another run on the dyno to see if we can't bust the 100.

There is a vid of the dyno run on the fb ek facebook page for those interested

[FJWALLY]

Bit more of a chat to Mark Trounsen the dyno Guy and a couple of things on the plan for later.

Firstly he made comment during the fitting of the springs that the valve height were a bit all over the place which was pretty disappointing given the head had been re-coed by Top Torque in Nunawading less than 500 miles ago so it's more than likely they didn't fit Inserts but just ground down the seats to find solid material and adjusted roughly when fitting the springs which were the wrong type as it had valve float even before the blower.
So to do it right the next step would be to pull the head and put inserts in and give the head the once over - thought about roller rockers but how far do you go ?

Secondly and most importantly is I need a new carby - the one I was given just has too much play in shafts etc so very hard to get idle and is a constant battle to prevent stalling out when coming off the revs - we can bump the idle speed up a touch to get by for now but it's at the point where we will start to encounter run on and running at those revs at idle not the best for the motor so I am on the search for a new to very good 1 3/4 SU carb with choke if anyone has one or knows where I can get one. Discussed the 2 inch but Mark feels it would be a lot harder to tune through the range and there is certainly no shortage of fuel with the 1 3/4. Plus the 2 inch has no choke so would be an issue for cold Melbourne starts.

Thirdly we need a little more tinkering with the Throttle Linkages - at the moment it is all a bit all or nothing on the go peddle and I want a bit more of a transition to make it more drivable.

Fourthly is the Bonnet Hinges and Springs - after seeing one of you chaps here who has moved the spring posts to the outside of the hinge I am going to do the same - Haven't got your PM yet Patrick - perhaps send me a txt to 0431163263 - that will clear the Carb bowl which is just touching on the Spring when Bonnet closed. I have removed spring for now and using the Broom Handle.

Water and Oil temps are nice and stable and no signs of any overheating after a couple of 20-30k runs on Sunday.

[Errol62]

Valve bounce was a factory feature, as was longevity. Bigger this stronger that faster pussy-cat slippery slope.

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[D-MAN]

Midel for the SU - when I was running twin SU’s on the fb I got them from them

http://www.sumidel.com/

[FJWALLY]

Yes SU Middle would be my preference but they have no new units in stock and at the moment at least 4 weeks but no guarantees as most factories are closed in the UK. New unit is 785$

They can re-furb mine with new shafts and butterflies and internals etc and say they are as good as new for 500$ but at least 4-6 weeks wait to get that done which I'd rather not have the car sitting that long again.

Alternative is fine a decent second hand unit and send them that to refurb so it can be a change over when ready.

Midel for the SU - when I was running twin SU’s on the fb I got them from them

http://www.sumidel.com/

[FJWALLY]

Updated engine bay


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[EK283]

Valve bounce was a factory feature, as was longevity. Bigger this stronger that faster pussy-cat slippery slope.

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I recall my grey engine that I flogged the living daylights out of had the built in rev limiter as well !!

Valve spring height in a stocker would be ok but in a performance engine the tolerances need to be better measured. This is why I do everything myself because you just can't get anyone to do good work, I don't know why that is ?????????????????????????????

Anyway the blower and sorting will be fun.

Greg

[Blacky]

Sooo .......... where are we at here ?????
Updates ????


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[FJWALLY]

Have been driving it around Blacky but trying to source a new or near new 1-3/4 SU is proving very difficult to sort out the idle issue

Doing some other bits and bobs in the meantime with hope of still getting to head north

Sooo .......... where are we at here ?????
Updates ????


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[Harv]

I've got a 20L tub of SU carbs, parts and bits. An part in particular that you need for the carb?

Cheers,
Harv

[FJWALLY]

I need a complete working one in same config as mine Harv - at least a rebuildable one I can send to Midel.

I've got a 20L tub of SU carbs, parts and bits. An part in particular that you need for the carb?

Cheers,
Harv