Speed Six Rebuild: Power 4.3 or 4.5?

[dvs_dave]

JR said:

dvs_dave said:

Bar higher quality components and a proper build, Power's engines are exactly the same design as the original TVR version which was of sound design.

It really is as simple as that.

According to you, now we know the difference between Str8six and Power: Str8six incorporate as many of the developments of the S6 as possible in their rebuilds but Power do their best to undo them and restore all of the original problem areas.

Not according to me...according to Dom. There are of course detail differences (including a revised head gasket), but not ones that could be detected without the aid of a micrometer and a rockwell tester. These I don't class as design changes, just detail revisions of the original.

On a standard rebuild Dom doesn't do any machining of the blocks other than what's required to achieve good surface matches as you'd expect. No additonal oil or water feeds are added.

STR8SIX rebuilds add the extra oil feed to the head, but apart from that I'm not aware of any other differences. Depending on how much you want to spend, there is of course the option with both for the later engine block which has additional water galleries running between each piston, which is nice to have, but it would seem not critical to engine performance or longevity.

Regards the FFF development, I believe that the first iteration actually came from the TVR Speed 12 development engine as that used buckets. The AJP8 doesn't share much, if anything with the AJP6.

Edited by dvs_dave on Tuesday 5th July 20:58

[Mattt]

Ah, that's a picture of splitting hairs, looked like a scratched T350 headlight at first!

[Tvr Power]

Speed eight said:

Hello RedSpike66.
Anyone can use John Sleath Race Engines...........call John on 01709 862075.

Apart from winning almost every drag racing series over the years...........
He owns and runs the fastest street legal car in Europe. The first car to run180Mph on pump gas in under 7 seconds
So he knows what he is doing I think.

Look, lets forget about RR. It HAS to be engine dyno first. To establish a base figure. Then RR and the type of RR has to be understood.
I do not want to sound all knowing, because I am not. But there are different types of RR that read the HP in different ways.
Have a talk with engine builders or Google for the information.

As for revving the Speed Six engine. OK.
Let us look at the maths.
If the 4.3 or 4.5 Six, which has a rod ratio of 1.43 is taken to 7250Rpm then the piston speed reaches 78.5Ft/sec............ do you realise just how fast this is?
A formula one car at 18000Rpm has a piston speed of 80Ft/sec......... I ask, is this good for piston life?

I ask these questions as an Engineer. Not because I am trying to put down any ones work. I just like to understand things.
And try to find out why the Six is allegedly making 0.111 HP/cc. But I can only make 0.0841HP/cc as can John Sleath.
I know that the engines are different, but this is a massive shift.


Regards.
Speed eight.

Here are pictures of our Race pistons which are actually the same pistons used on all 4.5ltr Speed Six rebuilds, these pistons have done 750 miles flat out track miles and 1500 road miles so far, pistons have been crack tested and measured all within manufactories tollerances, so for your statement above ill keep you posted when GT CUP ends this years

Dom

[dvs_dave]

Looks like the mods have may been clearing irrelevant posts.......which is a good thing.

[uli]

Tuscanuwe said:

I am going for a 4.3!
-new better balanced crankshaft (compared to a 4.0)
-saved a bit compared to a 4.5 (2400 bucks,incl vat)
-still high rev limit 7750!
-hope that the 4.3 is more bulletproof than any other!

hope to get my Tuscan back within next 4 weeks!

I will keep you informed

Uwe

Hallo Uwe,
habe selbst einen T350c seit 2003 und lese mit großem Interesse über die Upgrades von TVR Power. Vielleicht können wir mal telefonieren, würde gern Deine Erkenntnisse bislang hören. Gruß aus München, Uli. 0178-5295017

[DonkeyApple]

Not sure anyone could have said it better.

[dpd3047]

7750 RPM thats something piston speed 84 ft per second wow!! What power is making at that rpm.

[jcpgasoline]

Speed eight said:

Hello RedSpike66.
Anyone can use John Sleath Race Engines...........call John on 01709 862075.

Apart from winning almost every drag racing series over the years...........
He owns and runs the fastest street legal car in Europe. The first car to run180Mph on pump gas in under 7 seconds
So he knows what he is doing I think.

Look, lets forget about RR. It HAS to be engine dyno first. To establish a base figure. Then RR and the type of RR has to be understood.
I do not want to sound all knowing, because I am not. But there are different types of RR that read the HP in different ways.
Have a talk with engine builders or Google for the information.

As for revving the Speed Six engine. OK.
Let us look at the maths.
If the 4.3 or 4.5 Six, which has a rod ratio of 1.43 is taken to 7250Rpm then the piston speed reaches 78.5Ft/sec............ do you realise just how fast this is?
A formula one car at 18000Rpm has a piston speed of 80Ft/sec......... I ask, is this good for piston life?

I ask these questions as an Engineer. Not because I am trying to put down any ones work. I just like to understand things.
And try to find out why the Six is allegedly making 0.111 HP/cc. But I can only make 0.0841HP/cc as can John Sleath.
I know that the engines are different, but this is a massive shift.


Regards.
Speed eight.

Just found this on Wiki...

Highest specific engine output (power/unit displacement)
Petrol/Gasoline (naturally aspirated) piston engine - 118.81 kW (161.5 PS; 159.3 hp) per litre - 2009 Caparo T1 415.35 kW (565 PS; 557 hp) 3.496 L [6]
Note: 93.18 kW (126.7 PS; 125.0 hp) per litre - 2009 Ferrari 458 Italia 419.2 kW (570 PS; 562 hp) 4.499 L
Note: 92 kW (125 PS; 123 hp) per litre - 1999 JDM Honda S2000 184 kW (250 PS; 247 hp) Honda F20C engine 1.997 L

So, allegedly, the Caparo T1 makes 0.1593 hp/cc; the Ferrari 458 makes 0.1249 hp/cc; the Honda S2000 makes 0.1237 hp/cc.

A clear difference between the Speed Six and the three other engines previously mentioned is that the other three are much higher revving. In those three engines peak power is reportedly produced at 10500, 9000 & 8300rpm respectively, compared to the 4.5 Speed Six which peaks at 6700-7000rpm.

That would seem to suggest that 0.111 hp/cc isn't unrealistic for a high performance, moderately high revving engine like the Speed Six.

I think the limiting factor in all of these cases is the shape and length of the torque curve - i.e. if flattish torque can be maintained into high revs then more power will be produced per unit capacity. Before something breaks, of course!

[Tvr Power]

jcpgasoline said:

Speed eight said:

Hello RedSpike66.
Anyone can use John Sleath Race Engines...........call John on 01709 862075.

Apart from winning almost every drag racing series over the years...........
He owns and runs the fastest street legal car in Europe. The first car to run180Mph on pump gas in under 7 seconds
So he knows what he is doing I think.

Look, lets forget about RR. It HAS to be engine dyno first. To establish a base figure. Then RR and the type of RR has to be understood.
I do not want to sound all knowing, because I am not. But there are different types of RR that read the HP in different ways.
Have a talk with engine builders or Google for the information.

As for revving the Speed Six engine. OK.
Let us look at the maths.
If the 4.3 or 4.5 Six, which has a rod ratio of 1.43 is taken to 7250Rpm then the piston speed reaches 78.5Ft/sec............ do you realise just how fast this is?
A formula one car at 18000Rpm has a piston speed of 80Ft/sec......... I ask, is this good for piston life?

I ask these questions as an Engineer. Not because I am trying to put down any ones work. I just like to understand things.
And try to find out why the Six is allegedly making 0.111 HP/cc. But I can only make 0.0841HP/cc as can John Sleath.
I know that the engines are different, but this is a massive shift.


Regards.
Speed eight.

Just found this on Wiki...

Highest specific engine output (power/unit displacement)
Petrol/Gasoline (naturally aspirated) piston engine - 118.81 kW (161.5 PS; 159.3 hp) per litre - 2009 Caparo T1 415.35 kW (565 PS; 557 hp) 3.496 L [6]
Note: 93.18 kW (126.7 PS; 125.0 hp) per litre - 2009 Ferrari 458 Italia 419.2 kW (570 PS; 562 hp) 4.499 L
Note: 92 kW (125 PS; 123 hp) per litre - 1999 JDM Honda S2000 184 kW (250 PS; 247 hp) Honda F20C engine 1.997 L

So, allegedly, the Caparo T1 makes 0.1593 hp/cc; the Ferrari 458 makes 0.1249 hp/cc; the Honda S2000 makes 0.1237 hp/cc.

A clear difference between the Speed Six and the three other engines previously mentioned is that the other three are much higher revving. In those three engines peak power is reportedly produced at 10500, 9000 & 8300rpm respectively, compared to the 4.5 Speed Six which peaks at 6700-7000rpm.

That would seem to suggest that 0.111 hp/cc isn't unrealistic for a high performance, moderately high revving engine like the Speed Six.

I think the limiting factor in all of these cases is the shape and length of the torque curve - i.e. if flattish torque can be maintained into high revs then more power will be produced per unit capacity. Before something breaks, of course!

The only limiting factor I work with ( on my expense of coarse) Stop when it breaks hence why we are going 5 ltr

4.3s have been on the road now for 4 years, i had one engine that had a shrunk piston which i missed when in build and one more failure whilst in Poland which detonated the head gasket, all in all i have zero worries of 4.3 mechanical failures.

4.5ss have been on the road for 2 yrs, couple of failures on my own Sagaris which was down to my own machining errors, liners dropped because i forgot too press down to installed heights which causes MLS gaskets to instantly fail....

Dom

[DonkeyApple]

Dom, when do you reckon you'll reach the point that the head can't flow enough volume to make the most of an increased capacity? Or is it a case of running out of metal in the block long before this would be an issue?

[Tvr Power]

DonkeyApple said:

Dom, when do you reckon you'll reach the point that the head can't flow enough volume to make the most of an increased capacity? Or is it a case of running out of metal in the block long before this would be an issue?

Believe it or not the intake ports need to be smaller, 5.0 ltr im sure will work really well, i'll keep you all posted

Dom

[DJRC]

Ive avoided posting till now because Dom was still developing and tweaking and playing, but now Ive watched Danny spank the Sag around over the summer and be as fast as anybody, then damn it...I dont mind admitting I giggle like a schoolboy at the 4.5 and 5.0.

A 5ltr would get me back in a Sag. Dom you going to offer it, or you keeping with your original plan?

[Tvr Power]

DJRC said:

Ive avoided posting till now because Dom was still developing and tweaking and playing, but now Ive watched Danny spank the Sag around over the summer and be as fast as anybody, then damn it...I dont mind admitting I giggle like a schoolboy at the 4.5 and 5.0.

A 5ltr would get me back in a Sag. Dom you going to offer it, or you keeping with your original plan?

Im still working on my 5ltr, i will only be selling 5 ltrs for racing, oh and one in my sag



Dom

[Mattt]

What happened to the turbo plans?

[Tvr Power]

Mattt said:

What happened to the turbo plans?

Next project once we have achieved 24 hrs endurance race

Dom

[SAGRIFF]

5 litre Turbo Sag,

[jcpgasoline]

Tvr Power said:

Next project once we have achieved 24 hrs endurance race

Dom

When's the 24 hr endurance race happening?

[BCA]

3.6 litre Turbo T350c

[Gazzab]

That will be some power - isnt a 4.5 Supersport 450 bhp at the fly? So, plus a small amount of turbo power = an easy 500bhp or lots more should you turn up the wick.

[Tvr Power]

jcpgasoline said:

Tvr Power said:

Next project once we have achieved 24 hrs endurance race

Dom

When's the 24 hr endurance race happening?

Hoping to Do the 24 hr Britcar, awaiting Sponsors

Dom