RCR GT40 Cinderella in France

[Walter]

as for the pump there is a rule of thumb:

flow in lb/hr ~ 1/2 hp

e.g.: LS7: 510 HP -> 260 lb/h -> 164 l/h (regular gasoline!)

I run a Bosch-044 rated at 300lp/h

std. LS7s use injectors rated at 41.74 lb./hr. @ 58 psi (GM part number 12576341) - but there are others e.g. by Bosch...

 

[Walter]

your tuner surely knows more than me but you first should get the optimal injectors (considering the fuel pressure your pump can reliably deliver) and then fine tune fuel pressure in conjunction with ECU programming (my FASTX ECU needs to know fuel pressure as input and then determines squirt duration based on other target values)

 

[Walter]

Finally I adjusted the front and back suspensions, my parameters are the following (for race track only) :

Back per wheel
- Toe in 0.25°
- Camber -1°
- Caster 6.3°
- Height 114mm
Front per wheel
- Toe in 0.14°
- Camber -1.9°
- Caster ?
- Heigth 107mm
On the front I machined aluminum bushings to replace the stack of washers, because I moved completely forward the top arm
I had also to cut 1/4" of the steering end screw because the Toe adjustment was not possible.
With all those adjustments, the front tire is still passing very close of the back fiber glass archee, I will may be have to cut the portion in front of the tire.
Does one of you has the same experience, what minimum distance do you experience on your RCR car ?

Hello Jean-Marc: Did you with the upper also move the lower front A-arm mounting points to maximum forward position ? If so how difficult was it to remove/access the mounting bolts on/from the inside of the car? (This is necessary to transfer shims to the rear of these bolts). Greetings!

Finally I adjusted the front and back suspensions, my parameters are the following (for race track only) :

Back per wheel
- Toe in 0.25°
- Camber -1°
- Caster 6.3°
- Height 114mm
Front per wheel
- Toe in 0.14°
- Camber -1.9°
- Caster ?
- Heigth 107mm
On the front I machined aluminum bushings to replace the stack of washers, because I moved completely forward the top arm
I had also to cut 1/4" of the steering end screw because the Toe adjustment was not possible.
With all those adjustments, the front tire is still passing very close of the back fiber glass archee, I will may be have to cut the portion in front of the tire.
Does one of you has the same experience, what minimum distance do you experience on your RCR car ?

 

[Jean-Marc]

Hi Walter, I was lucky, I did not moved the lower front arm, because it was already setup for the maximum forward position. To acess to the bolt I suppose you have to be flexible and ramp inside the body ! See you.

 

[Walter]

yes, I may have to hire a midget for the project ;-)

 

[Jean-Marc]

I little update. The car is still on the dyno and after putting new larger injectors and a new pump, the test runs are not promising. The power curve is stucked at 410 hp between 6000 and 7000rpm. Injectors are only at 47% of capacity when the A/F ration is at 12.9. The ignition timing advance seems to have no influence on the power, and to run it at idle about 20° is needed and the pick power is rreached with 32°.
We measured the compression ration and found 10 only. The engine seems new, the valve lift is in the range of 0.57" ???
On top of it when we measure the temperature of the collectors we only found about 100°C or 212°F even if we run the car at full power. Oil pressure is corect, water temperature is 195°F.
It is a full roller engine built by T&L in USA and delivered with the kit in England 14years ago. From the previous owner the engine was dyno tested with a carburator, but since it was never used and transformed with a 8 stacks injection also never tested... I do not know what to check and in wich direction to look. I more suspicious on the injection (Accel type) than on the engine construction itself, but I have no doucmentation on the engine and I even do not know the inside components except what I see, Dart bloc, Victor Junior heads, Borla injection, Jessel roller rockers, SFI damper, all good stuff...
Any Idea ?
Does anybody knows how I may contact T&L in USA ?

 

[Jean-Marc]

I last info, it seems that the engine was modified or effectivelly built with T&L base by Mike Hubbart from Hubbart engineering in UK, but I am not shure that they are still in business I cannot contact them.
Does anybody in UK knows how to come in contact with Mike ?

 

[Walter]

Hello JM: 410hp is not exactly a desaster ;-) Do you have the data sheets from back when the engine was tested with carbs?

 

[Jean-Marc]

Hello Walter, Of course, I got worst catastrophes in the past. The problem is more the behavior of the engine (temperature, ignition timing) that seems not right. The second thing, is that the vendor (not the one that built the car) told me a different strory.
The engine is suppose to be a copy of an engine built with the spec of an article of Mustnag & Fast Ford magasine from November 2008, that shows 550Hp with carburator ! I do not have any data from the time the engine was equipped with carburator, except I know it had an Edelbrock inlet that I got as extra part.
See the article in copy.

 

[JP Verweij]

Wel my expriances with Dyno's, you can go to three differend dyno's in one day, giving you all differend numbers.
I am never interested in numbers. I am interrested in a good runner.
In Holland we say, American BHP & Dutch BHP.
Haven't seen an American BHP advertised engine actualy deliver it. But again, going to three differend dyno's in one day can give you three differend numbers, though the curves should be the same.

Do you have specs with your engine?

 

[Jean-Marc]

JP, I have zero spec with the engine, the only data are the ones descibed in the the Mustang 1 Fast Ford article. I am pretty sure that the Bore is 4.155" and the stock 3.4". I made a came profile a few months ago, except that the angular position in not the absolu value versus the TDC, but a relative position versus a pointer. It is why I do not know the overlap at this time. I shall redo the measurement.

For the Exhaust valve

For the inlet valva

For the inlet valve

 

[JP Verweij]

So basicly, you have an unknown engine with unknown specs.

Been there. Thats why me & my wife always take engines apart (@ the cost of just a gasket kit) to see what we have.
As we say it, it could be refurbished with just a paint brush.. till you verified it with your own eyes.

In my opinion, stop guessing. Take that engine apart and measure it all up. Note all details like cam markings and piston markings and crankshaft markings and verify till you sure its all correct.
At the moment it could still be a 302.

It will cost you a gasket set, thats all.

 

[Jean-Marc]

JP you are right, except on top of a gasket kit, it require 2 days of deassembly and reassembly, but I am retired.
But first I want to be sure that the injection parameters in the ECU are the good one and it optimized.

 

[Jerry Irwin]

JP you are right, except on top of a gasket kit, it require 2 days of deassembly and reassembly, but I am retired.
But first I want to be sure that the injection parameters in the ECU are the good one and it optimized.

Gosh....
Wish i could take out an engine, diss-asemble, check all parts, replace as required and then re-assemble and refit in car.
ALL in 2 Days......LOL...
Jeremy

 

[JP Verweij]

I little update. The car is still on the dyno and after putting new larger injectors and a new pump, the test runs are not promising. The power curve is stucked at 410 hp between 6000 and 7000rpm. Injectors are only at 47% of capacity when the A/F ration is at 12.9. The ignition timing advance seems to have no influence on the power, and to run it at idle about 20° is needed and the pick power is rreached with 32°.
We measured the compression ration and found 10 only.

From the previous owner the engine was dyno tested with a carburator, but since it was never used and transformed with a 8 stacks injection also never tested... I do not know what to check ?

Well your AFR is perfect even with to much injector as you only run them at 47%
You measured compression, not compression ratio. 10 bar is actualy good, if its 10 psi I would worry and it would explain why you need 20' initial timing.
Usualy peak power sits between 32 & 38 total advance, all in at 4000rpm.

Camshaft dictates powerband. So apearendly your cam has its powerband till 6000-7000rpm.
Well a 347 Stroker will not be a 8000rpm 289 screamer. Strokers don't like high rpm unless all internals are made for that purpose, but usually it won't last.

As you know nothing about your engine. No specs, no bhp numbers, not knowing if it was run in on a dyno (not even knowing if even the cam was properly dialed in and more importand had a cam break in).
I would not bother in spending more dyno time to sort fueling. AFR is good and didn't need more injector size after all.

If you are not satisfiet with the current numbers, only way is to take the engine apart and see what you got.

And yess, it also takes me 45 minuts to take the transaxle out & after that about 20 minuts to take the engine out.
After that when the engine is in the stand its prr prrr prr within an hour engine totaly apart on the table.
Ofcourse you can take your time as you should.

Injector size is given by an amount of Ohm and an amount of fuel pressure (pre calculated by the manufactorer).
If you change Voltage or pressure you also change the amount of CC's / minute they'll suply.

So if an injector is rated lets say 330cc @ 2.5bar it will run into 400s at 3,5-4bar and even more at 5bar fuel pressure.
(You find that info at the spec table of your injectors).
Also spray pattern has influence, one hole or multiple holes spraypatern and under or above throttles.

 

[Jean-Marc]

JP, Thank you. I do not intent to use the engine in high rpm, 5500 to 6000 rpm should be sufficient. Of course 400hp should be also sufficient but I just worry on the behavior, why the exhaust manifold are so cold, why the ignition timing a almost no influence ???
Regarding the injectors, we mounted Bosch #0280 158 279 375g/mn 50lb/h 12ohm. The injection pressure should be 50psi (not sure, the car is at a distant place).