4 Valves per cylinder ?

[wadsapple]

I was at my engine builder,s workshop today picking up one of my race engines that they have been upgrading for me.I was nosing about as you do when in a workshop that has all sorts of goodies and saw that they have built a AJP V8 engine with four valves per cylinder.Has this been done before? Should i be thinking that this would be a good upgrade for my AJP engines ?

[wadsapple]

no it doesn't look like a race engine block they are like hens teeth ,probably for road use.i have a race AJP engine in a challenge car i might upgrade if the heads were a good option.i probably should have asked at the time.still what advantages would you have in a road engine ?

[wadsapple]

Got some more news on this last night.This engine is been developed and they have moved forward a bit with it.The heads fit the block studs perfectly.The bore spacing will be the same.The cams will be belt driven so they say and all engines will be 3 stage dry sump system,the old triple pump will be discarded as will all the gears and chains.
Now for the juicy bit,power outputs Projected will be between 480bhp for the 4.5 version and upto 700bhp for the 4.8 full race engine as for torque it will come out close to 390ft lbs upto 475 ft lbs and a turbo version could well hit 1000 bhp so i,m told but we shall see how things develope.No harm in trying as the saying goes.I have put my name on the first 4.8 race engine so i hope things work out for them.

Edited by wadsapple on Thursday 11th October 14:09

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Just to let you know the 12K figure is for a complete engine without a doner and it is at this stage just a guesstimate.More precise costings will follow.It would be conciderably less than an LS conversion i would think.

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bionicjim said:

I will let you keep guessing what the heads are off

I hope you do to for the time being

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As i understand it the power figures are always a little hard to predict.

They`ve run a dyno program on the 4.7 AJP engine with race cams ported heads ect it made maximum power of
of 426 bhp @ 7000 rpm and 372 ft lbs of torque @ 5000 rpm this is with tube headers and full exhaust system, this is the same program as used with the 4 valve heads .Just as a comparison they ran the same program as a 4.5 with just high lift cams 4 v heads and tube headers and full exaust system the power figures were 480 @ 7500 rpm and 391 ft lbs torque @ 5000 rpm .

[wadsapple]

It is as i said earlier very difficult sometimes to see where/how engine numbers come from and not wishing to get into the finer details of the build,as i,m sure you can understand a lot of time and effort has been put into this so far before it was put on here to discuss, to spell out all the answers for you would be unfair at this stage,Dom9 has the right train of thought when he is thinking about valve curtains.Just to add that i could not beleive that a 2.5lt F1 engine produces 850 bhp at 17.500rpm NA but it does i,m sure.

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Why So negative about a project that is obviously intersting to discuss on here.I didn,t see anywhere that it was stated it was surposed to be a comercial project,why can,t it be about a couple of chaps having a go at sorting somethink that hasn,t been done before.

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we were thinking of sticking it in this to test it as this car is sorted and already runs 500+ bhp....