Speed Six Rebuild: Power 4.3 or 4.5?
Discussion
dpd3047 said:
Engine dyno`s measure torque its then converted into bhp, but some rolling roads measure bhp and convert this into torque these are inertia type DynaJet for one, the other type is steady state these measure torque and convert to bhp thats the one i would trust if set up correctly as a dynodynamics,torque is what makes the car move, if you use big cams in an engine you cant pull away at low revs as there is not enough torque to move the car look at and F1 engine that has to rev at 12000 rpm to pull away and it has around 200 ft lbs of torque at 18000 rpm but makes 720 bhp.
Really?BHP is a function of torque and rpm - so surely all measure torque?
dpd3047 said:
You have consider the mass now i know that at 7000 rpm the load on an s6 piston is 3.5 tons thats from AM himself thats why the engine suffers from torsional vibration, tvr fitted the fluid damper to try and cut down on this, the 4 litre suffers more than the 3.6 engine because of the longer stroke if you incease the stroke you increase friction, heat, piston speed, and torsional vibration. The big problem with the 4.0 litre is the conrod which the small end is heavier than the big end by 2grms that is engineering madness and as for the main caps two studs and just a locater dowel no wonder the caps walk and liners move.
TVR Power and STR8SIX's customers have found beyond all doubt now, that when correct high-spec components are used and meticulously assembled, TVR's design doesn't suffer from.... .....anything at all, even when used hard on track days, and can win races in GT Cup against the latest opposition.
Unlike earlier efforts by several companies who could talk the talk, but not deliver remotely reliable S6 engines, which may ring a bell.
tail slide said:
TVR Power and STR8SIX's customers have found beyond all doubt now, that when correct high-spec components are used and meticulously assembled, TVR's design doesn't suffer from....
.....anything at all, even when used hard on track days, and can win races in GT Cup against the latest opposition.
Unlike earlier efforts by several companies who could talk the talk, but not deliver remotely reliable S6 engines, which may ring a bell.
That's a good point and raises a question. I recall a few years ago a big spat on here about a company that charged commical sums and then either failed to deliver or delivered a lump of junk. I think they ended up going bust in the end? I just recall some really angry people who spent ages on PH savaging anyone who questioned their choice and then when they turned out to be right turned on the company?.....anything at all, even when used hard on track days, and can win races in GT Cup against the latest opposition.
Unlike earlier efforts by several companies who could talk the talk, but not deliver remotely reliable S6 engines, which may ring a bell.
But that aside, what would the differences have been between those rebuilds and the ones being done now? Is is down to just using better quality / more appropriate parts or was it down to shonky workmanship?
My understanding is that Str8six just to rebuilds using kit etc supplied by Power, so it would only be RG that offers something different? Meaning just 2 companies really doing rebuilds/upgrades per se. Why did the others fail?
Well there's someone posting on this thread that most certainly has first hand answers to that so it would be nice of them to come forward and explain things from their perspective.
However I think the fact of the matter is that he too was duped by Melling and his claims that TVR's design changes were the cause of the problems, which we now categorically know not to be the case.
However I think the fact of the matter is that he too was duped by Melling and his claims that TVR's design changes were the cause of the problems, which we now categorically know not to be the case.
dvs_dave said:
Well there's someone posting on this thread that most certainly has first hand answers to that so it would be nice of them to come forward and explain things from their perspective.
However I think the fact of the matter is that he too was duped by Melling and his claims that TVR's design changes were the cause of the problems, which we now categorically know not to be the case.
I thought that someone who had the original Melling designs had recently checked them against a standard S6 and found that TVR had made no changes to his design and that if there were any inherent design problems it was solely the responsibility and failure of Melling and not TVR?However I think the fact of the matter is that he too was duped by Melling and his claims that TVR's design changes were the cause of the problems, which we now categorically know not to be the case.
DonkeyApple said:
dvs_dave said:
Well there's someone posting on this thread that most certainly has first hand answers to that so it would be nice of them to come forward and explain things from their perspective.
However I think the fact of the matter is that he too was duped by Melling and his claims that TVR's design changes were the cause of the problems, which we now categorically know not to be the case.
I thought that someone who had the original Melling designs had recently checked them against a standard S6 and found that TVR had made no changes to his design and that if there were any inherent design problems it was solely the responsibility and failure of Melling and not TVR?However I think the fact of the matter is that he too was duped by Melling and his claims that TVR's design changes were the cause of the problems, which we now categorically know not to be the case.
Really?? Not heard that one.
Couple of obvious external differences between the AJP6 and the Speed Six is the oil filter changed sides and the addition of the harmonic balancer so that pretty much puts that one to bed.
As a side note people bang on about the addition of a harmonic balancer as though it's a bad thing. It's generally good practice to do so?? BMW and Merc straight 6 engines appear have them (as well as the V8's) so not sure why people pooh pooh them so much. Engines vibrate....if you can easily reduce the vibration and also improve engine life at the same time, why wouldn't you add one????
Couple of obvious external differences between the AJP6 and the Speed Six is the oil filter changed sides and the addition of the harmonic balancer so that pretty much puts that one to bed.
As a side note people bang on about the addition of a harmonic balancer as though it's a bad thing. It's generally good practice to do so?? BMW and Merc straight 6 engines appear have them (as well as the V8's) so not sure why people pooh pooh them so much. Engines vibrate....if you can easily reduce the vibration and also improve engine life at the same time, why wouldn't you add one????
dvs_dave said:
Really?? Not heard that one.
Couple of obvious external differences between the AJP6 and the Speed Six is the oil filter changed sides and the addition of the harmonic balancer so that pretty much puts that one to bed.
As a side note people bang on about the addition of a harmonic balancer as though it's a bad thing. It's generally good practice to do so?? BMW and Merc straight 6 engines appear have them (as well as the V8's) so not sure why people pooh pooh them so much. Engines vibrate....if you can easily reduce the vibration and also improve engine life at the same time, why wouldn't you add one????
I6 engines are well known for suffering from torsional vibration, due largely to the length of the crank. Therefore harmonic dampers are commonly used to help absorb this. Not using a damper where one is required can have seriously detrimental effects on engine longevity!Couple of obvious external differences between the AJP6 and the Speed Six is the oil filter changed sides and the addition of the harmonic balancer so that pretty much puts that one to bed.
As a side note people bang on about the addition of a harmonic balancer as though it's a bad thing. It's generally good practice to do so?? BMW and Merc straight 6 engines appear have them (as well as the V8's) so not sure why people pooh pooh them so much. Engines vibrate....if you can easily reduce the vibration and also improve engine life at the same time, why wouldn't you add one????
I would also add the the accuracy of engine balancing is critical to a smooth, long lasting engine. Based on the findings from my AJPV8 rebuild this was not an area that TVR paid much attention to...
Anyone can rent our Engine dyno if they want.It set up for all TVR engine Rover,AJP and Speed six
www.enginedyno.co.uk
www.enginedyno.co.uk
JR said:
This thread is becoming a series of posts that are complete fantasy. All of the above has been on PH correctly quite a few times and I'm sure that you know better than your mischievous post.
What am I missing here?I'm well aware that I tend to be mischievous but didn't think I was here.
Vixpy1 said:
Mattt said:
Engine dyno, not rolling road.
I know of a Piper engine dyno for sale in Essex if anyone fancies it.
Half the bloody world has tried to flog me that dyno in the last few weeks I know of a Piper engine dyno for sale in Essex if anyone fancies it.
JR said:
DonkeyApple said:
I thought that someone who had the original Melling designs had recently checked them against a standard S6 and found that TVR had made no changes to his design and that if there were any inherent design problems it was solely the responsibility and failure of Melling and not TVR?
OK, briefly: the original Melling design had quite a few changes, most obvious visually are the changes to the ancilliaries mounting which was originally a novel quick release system. The main architecture of the engine that gives the ability to produce engines of nearly twice the power to the RV8 counterparts with far better mpg was kept. TVR moving the swept arc of the finger followers created an inherent wear problem that, combined with TVR using sub-standard parts, created a sideways force on the valve/valve stems and the finger follower problems.rottey said:
Anyone can rent our Engine dyno if they want.It set up for all TVR engine Rover,AJP and Speed six
www.enginedyno.co.uk
Bookmarked for future reference www.enginedyno.co.uk
Note: The engine can be run-in on the dyno too... saves driving like a p
y for 1500 miles Edited by RedSpike66 on Thursday 30th June 10:01
JR said:
JR said:
DonkeyApple said:
I thought that someone who had the original Melling designs had recently checked them against a standard S6 and found that TVR had made no changes to his design and that if there were any inherent design problems it was solely the responsibility and failure of Melling and not TVR?
OK, briefly: the original Melling design had quite a few changes, most obvious visually are the changes to the ancilliaries mounting which was originally a novel quick release system. The main architecture of the engine that gives the ability to produce engines of nearly twice the power to the RV8 counterparts with far better mpg was kept. TVR moving the swept arc of the finger followers created an inherent wear problem that, combined with TVR using sub-standard parts, created a sideways force on the valve/valve stems and the finger follower problems.I'm sure that I've heard that the person who now owns the AM blueprints has confirmed this is the case?
But I am intrigued as to what the changes Power and RG have implemented, apart from using better components, that are making their engines last and run better in contrast to earlier rebuild companies which seemed to result in products which still failed, although I'm assuming they also used better quality components and knew what they were doing?
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