475bhp 4.0 litre SP6 engine !
Discussion
Unless I've missed it, I'm staggered that Sprint has been out for over a week now and there has been no comment on here regarding the 5 pages given over to Racing Green to showcase their new, jointly developed with Ultimate Performance, SP6 FFF head design and the power targets they are setting for it.
475bhp sounds an awful lot from a 4.0 litre and presumably will cost an awful lot - something that's not mentioned in the article. Presumably though, it will cost more than the c£9k they were charging for the original FFF engine rebuild ?
Thoughts / comments ?
475bhp sounds an awful lot from a 4.0 litre and presumably will cost an awful lot - something that's not mentioned in the article. Presumably though, it will cost more than the c£9k they were charging for the original FFF engine rebuild ?
Thoughts / comments ?
s5tvr said:
Unless I've missed it, I'm staggered that Sprint has been out for over a week now and there has been no comment on here regarding the 5 pages given over to Racing Green to showcase their new, jointly developed with Ultimate Performance, SP6 FFF head design and the power targets they are setting for it.
475bhp sounds an awful lot from a 4.0 litre and presumably will cost an awful lot - something that's not mentioned in the article. Presumably though, it will cost more than the c£9k they were charging for the original FFF engine rebuild ?
Thoughts / comments ?
There are quite a few comments in the s/c thread. In short: suggested that the FFF head is based on the idea emplouyed for the S12 head. Power figures for the first and the second FFF heads are all claims as no-one will provide a FFF head to test on any rig on the same date as a FFS6 head.475bhp sounds an awful lot from a 4.0 litre and presumably will cost an awful lot - something that's not mentioned in the article. Presumably though, it will cost more than the c£9k they were charging for the original FFF engine rebuild ?
Thoughts / comments ?
I cant believe your all getting sucked into this, if you think about it the engine would have to rev to 8500 rpm thats a piston speed of over 85 feet per second, thats faster than an F1 engine at 18000 rpm, the other problem is torsional vibration at that speed through the crankshaft, no matter how well the head flows its what is bolted onto it that is the restriction, throttle plates, air box, the intake size the exhaust manifolds and system. You can draw your own conclusions.
Edited by dpd3047 on Monday 20th September 20:21
I`m sure that the chap who has worked all of this out would have taken those points into consideration dont you, he does have a pretty impressive cv.
on the one side you have Doms 4.3 and 4.5 engines on the other there is a decent cylinder head, perhaps someone with very deep pockets may come along and have both options done on their car.
on the one side you have Doms 4.3 and 4.5 engines on the other there is a decent cylinder head, perhaps someone with very deep pockets may come along and have both options done on their car.
The article reads like the head alone will magic up all this extra power...i just dont see how without changing everything else on the engine...deep pockets seem mandatory to turn such a bold claim into reality
I also dont see evidence of these kinds of power levels without extra cc's, or extra revs or a s/c. The FFF head while very pretty isnt the whole answer surely ??
I also dont see evidence of these kinds of power levels without extra cc's, or extra revs or a s/c. The FFF head while very pretty isnt the whole answer surely ??
thats correct, bucket tappets do not work in the same way to get anywhere near the finger follower set up you would have to run variable valve timing as in the bmw engine. If you look at the profile of a standard cam you will see the profiles are a mirror image of each other the inlet has has fast opening and slow closing, the exhaust is slow opening and fast closing also the shape of the follower also affects the valve acceleration the standard tvr follower is slow on the opening just off the seat where as the Al Melling design is faster this allowes smother running and is less harsh.
Rather than rake over what seems to me to be 3rd or 4th hand inaccurate hearsay, let's stay on topic
For the true diletantes amongst us (thank god for wikipedia cos I didn't know what it meant either) then can someone just explain how a cylinder head alone can add over 100bhp to the s6
Seems like something about the intended setup wasn't mentioned in the article
For the true diletantes amongst us (thank god for wikipedia cos I didn't know what it meant either) then can someone just explain how a cylinder head alone can add over 100bhp to the s6
Seems like something about the intended setup wasn't mentioned in the article
shaunsmith said:
dpd3047 said:
thats correct, bucket tappets do not work in the same way to get anywhere near the finger follower set up you would have to run variable valve timing as in the bmw engine. If you look at the profile of a standard cam you will see the profiles are a mirror image of each other the inlet has has fast opening and slow closing, the exhaust is slow opening and fast closing also the shape of the follower also affects the valve acceleration the standard tvr follower is slow on the opening just off the seat where as the Al Melling design is faster this allowes smother running and is less harsh.
Are you the dilettante (Dave Davies) who was Autocraft! 'Speed Six PIONEER'. That ruined countless engines, cost many good people off here alone Tens of Thousands & misery. Surely not?
I wonder why no reply on here yet he emailed me personally asking me who I was, don't know you & not had dealings with you............
My post was a simple question, easy answer Yes or NO!
No hearsay, FACT.
Dilettante simply means a person who dabbles with something that they know little or nothing about.
Mr Hill, nearly forgot, back on topic.
My post was a simple question, easy answer Yes or NO!
No hearsay, FACT.
Dilettante simply means a person who dabbles with something that they know little or nothing about.
Mr Hill, nearly forgot, back on topic.
shaunsmith said:
I wonder why no reply on here yet he emailed me personally asking me who I was, don't know you & not had dealings with you............
My post was a simple question, easy answer Yes or NO!
No hearsay, FACT.
Dilettante simply means a person who dabbles with something that they know little or nothing about.
Mr Hill, nearly forgot, back on topic.
It is dave yes. He's been amazing helping me to rebuild and upgrade my s6 top end. I don't think diletante is accurateMy post was a simple question, easy answer Yes or NO!
No hearsay, FACT.
Dilettante simply means a person who dabbles with something that they know little or nothing about.
Mr Hill, nearly forgot, back on topic.
He's supplied me a very smart refurbed head with new set of enhanced followers, enhanced cams, springs, valves and guides, improved oil ways etc. Really running nicely now. Sounds like a different engine. Now I'm a diletante for sure but one with his sleves most definately rolled up and hands very dirty
That's why I'm so sceptical about the rg fff claims because dave has been clear all along that only substantial changes to the whole setup would bring extra power. I'm after reliability and fun rather than more power per-se
Anyway I guess time will tell if they get above 400
PetrolHeadPete said:
shaunsmith said:
I wonder why no reply on here yet he emailed me personally asking me who I was, don't know you & not had dealings with you............
My post was a simple question, easy answer Yes or NO!
No hearsay, FACT.
Dilettante simply means a person who dabbles with something that they know little or nothing about.
Mr Hill, nearly forgot, back on topic.
It is dave yes. He's been amazing helping me to rebuild and upgrade my s6 top end. I don't think diletante is accurateMy post was a simple question, easy answer Yes or NO!
No hearsay, FACT.
Dilettante simply means a person who dabbles with something that they know little or nothing about.
Mr Hill, nearly forgot, back on topic.
He's supplied me a very smart refurbed head with new set of enhanced followers, enhanced cams, springs, valves and guides, improved oil ways etc. Really running nicely now. Sounds like a different engine. Now I'm a diletante for sure but one with his sleves most definately rolled up and hands very dirty
That's why I'm so sceptical about the rg fff claims because dave has been clear all along that only substantial changes to the whole setup would bring extra power. I'm after reliability and fun rather than more power per-se
Anyway I guess time will tell if they get above 400
I'll tell you what I'll do, when he has paid back all the additional monies to all the people who's engines he ruined or whatever as a gesture, only then I'll retract the Dilettante Tag which he rightly deserves...
Good luck with motor
The only way to significantly increase power without increasing the capacity is to increase the revs.
Perhaps the revised RG engine head design allows for higher revs? Coupled with a short throw crank and a bore increase, a more over square stroke will accommodate the higher revs without silly piston speeds. A short throw crank will kill the torque though.
Perhaps the revised RG engine head design allows for higher revs? Coupled with a short throw crank and a bore increase, a more over square stroke will accommodate the higher revs without silly piston speeds. A short throw crank will kill the torque though.
dvs_dave said:
The only way to significantly increase power without increasing the capacity is to increase the revs.
Perhaps the revised RG engine head design allows for higher revs? Coupled with a short throw crank and a bore increase, a more over square stroke will accommodate the higher revs without silly piston speeds. A short throw crank will kill the torque though.
As said above, by definition that cannot be done by working on the head only.Perhaps the revised RG engine head design allows for higher revs? Coupled with a short throw crank and a bore increase, a more over square stroke will accommodate the higher revs without silly piston speeds. A short throw crank will kill the torque though.
dvs_dave said:
The only way to significantly increase power without increasing the capacity is to increase the revs.
Not quite true. increasing capacity on an engine whose head is already at flow maximum only moves that same hp down the rev range eg:3.6 makes about 350bhp at 7750rpm, 4 litre makes about 350bhp at 7000rpm. The head/cam dictates the outright flow potential of the engine, therefore it's available hp ceiling. As I see it, improving the head is the most significant single improvement you can do to a sp6.
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