roller lifters with 2.8

[veekuusi]

Yesterday I went to the race track for a free practice.
This is what happened:









So, nothing very extraordinary, just a little oil pressure issue.
7000 rpm, 4th gear, some 100 mph and full stop.

[ericjon262]

Hey Mr Ericjon 262, you don`t know how right you are.
That was the original plan for this engine.Plan A.
But I thought I could get the 300 hp out of this engine with a single carb.
I did not understood completely the importance of the runner lenght.
Big guys say, minimum lenght of a runner for this aplication is 37 cm (that is some 15")

I decided to take the plan B and C (3-bbl and 4-bbl carbs).
Now it seems that I "have to wait one round and start from original plan A".

My friend is driving this race series also with a old Ford.
The engine is Pontiac Super Duty (4-cyl. race engine).
He has 2 2bbl Weber carbs, he is using only 3-throttles, 1 is deleted.
3 throttles -> plenum -> 4 runners to engine
We are the only two persons in this very series that are making use of this
rule of less throttle plates than cylinders.

superduty's can crank out some serious numbers, but your friend needs to be prepared to pay out the butt for parts! something else I thought about that may work for your application would be large motorcycle carburetors, like used on large Vtwin customs here in the USA, I don't know how much air they flow though.

[veekuusi]

what about a crossram like described earlier with 2 2bbl carbs? you'd have the same number of throttle plates as the single 4 bbl, and longer runners.

Hey Mr Ericjon 262, you don`t know how right you are.
That was the original plan for this engine.Plan A.
But I thought I could get the 300 hp out of this engine with a single carb.
I did not understood completely the importance of the runner lenght.
Big guys say, minimum lenght of a runner for this aplication is 37 cm (that is some 15")

I decided to take the plan B and C (3-bbl and 4-bbl carbs).
Now it seems that I "have to wait one round and start from original plan A".

My friend is driving this race series also with a old Ford.
The engine is Pontiac Super Duty (4-cyl. race engine).
He has 2 2bbl Weber carbs, he is using only 3-throttles, 1 is deleted.
3 throttles -> plenum -> 4 runners to engine
We are the only two persons in this very series that are making use of this
rule of less throttle plates than cylinders.

[ericjon262]

what about a crossram like described earlier with 2 2bbl carbs? you'd have the same number of throttle plates as the single 4 bbl, and longer runners.

[veekuusi]

Does the stock LIM come up too high to run a custom upper?

The situation is very different when you have fuel mixed in the air.
You can have an intake of very many angles ( even very sharp ones) when there is no fuel.
But fuel makes it different.Fuel splashes to the outer wall of a runner , which interferes the air/fuel mixture.
And the air becomes "heavier", it doesn`t move so fast.
That is why you must keep the runners "straight" as possible.

There is no problem when you have fuel injection.
But in my case, using a carb makes things much complicated.

I try to explain the rules of this historic race a bit.
A car has a weight to hp ratio.
The more hp , the heavier the car.
For example when you have a 2.0 liter engine with 4-cyl. , 4-valve/cyl. , fuel injection, the weight of a car is the same with
a car with 2.8 liter engine ,2-valve/cyl,carb AND LESS THROTTLES THAN CYLINDERS.
The number of throttles can be in my case 1-5 in a 6-cylinder car.The calculated hp number keeps the same .

So the "normal" hp of a 2.0 fuel injected tuned up engine is something like 200-250 hp in this series,
and I try to gain at least the same , rather more out of my 2.8 engine.
It is "easier" to play with fuel injection, but I do not want do it the easy way.

[caffeine]

Does the stock LIM come up too high to run a custom upper?

[trotterlg]

You may have seen this, stock LIM and custom upper:

[34blazer]

How about a stock LIM with some sort of a custom upper? Probably wont have to worry too much about sealing to the heads. I think once you get the intake sorted out its going to make closer to 300hp.

Sick build!

[veekuusi]

Hes very limited on what he can run for a carb though, I doubt he could run two.





So it was this combo that got you the 255 that you posted about when the Capri was running on the dyno?

Yes, that was the combo seen in this video:

http://www.youtube.com/watch?v=VdxCqtoqvS8&feature=c4-overview&list=UUX30SFBRQv9PiufHKr0sSnw

Extension tube , 2 x plenum , 3 bbl carb
255 whp , 2.8 V6

[trotterlg]

How about a nice big sidedraft into a modified upper intake and stock LIM? Larry

[3400-95-Modified]

Even the stock LIM on the aluminum head engine provides longer runners than the one that he made up. Must be a height problem he has to deal with. Larry

Well that's because ours cross over and then meet a plenum, he has to run to the center and then put the carb there, so yes mostly due to height constraints but also the location of where the runners are going. He tried to replicate that with the Holley intake but it's not enough.

[Purple pit]

Yeah I thought about that, but I'm not sure what he has over there(that 3bbl was new to me).

Wonder what that center tube is for on that cross ram.

[trotterlg]

Even the stock LIM on the aluminum head engine provides longer runners than the one that he made up. Must be a height problem he has to deal with. Larry

[3400-95-Modified]

Hes very limited on what he can run for a carb though, I doubt he could run two.





So it was this combo that got you the 255 that you posted about when the Capri was running on the dyno?

[ericjon262]

Man that is pretty damn good. Hey I've got a long shot for you. Have you ever seen the old Mopar cross ram? That put the carbs out past the valve covers. Which made room for very long runners and kept the carbs under the hood.
The stock 2.8 FI intake is a cross ram, so why not just build a bigger Mopar style?

funny, the exact same engine popped in my mind too, it was an old chrysler Hemi, I forget the name of it though...

2 4bbls on a long crossram, pretty wicked looking.