Are we missing something? Exhaust Manifold Thread II

[Barry911]

Peter, I wonder if valve overlap, and exhaust scavenging (pulses?) is what can lift N/A engines over the 100% mark? Forgive the basic terms: I'm only a metal basher.

[Peter Cobbold]

BMW M54 3.0 engine (albeit with variable valve timing and four valves per cyl), but no charging.

 

Six cylinders

2979cc

230 bhp @ 5900 rpm

17,700 intake strokes per minute

Air per intake required: 0.552

Cylinder capacity 496.5

Volumetric efficiency = 552/496.5. = 111.8 % VE

 

Or have I done that wrong?

 

Only picked the M54 as I remembered it was 230 bhp, and is (obviously) six cylinder. As it happens I rate it as a travesty to the BMW name after the fabulous M52, but that's for another day (and forum).

 

Anyway, all that aside, forgive me here, but this is the second thread on the subject, and after many posts, one banning, much mashing of teeth and wringing of hands (not to mention entertainment, interesting debate and something about wind farms), we still haven't addressed the original question. Neil, I know you said it's elsewhere, but I've looked and looked but can't find it. I'm no tuner, and it looks as though my hopes for a career in the detection business have been dashed again!

 

So, and hold onto your hats here folks, because it's coming up again .... what is the sensible state of tune / BHP limit for the standard, twin outlet Triumph TR6 exhaust manifold. Ie if I aimed for an honest 150-160 bhp, am I going to have to ditch it. If so, what would be the maximum?

 

Oh yes, don't let me stop the side debates: they've been fascinating, and judging by the thread hit rate, it's not just me that thinks so.

Barry,

That calculation is correct. I blame the high VE on VVT, four valves per cylinder, short stroke. Cant see a fixed cam, long-stroke, two-valve TR getting up there.

Peter

[Barry911]

Oh, I agree, it was more a point of principle: that the calculation, counter to the implication, doesn't absolutely rule out V/E's over 100%.

 

I'm not coming at this from any knowledge base at all, and had we not been talking about a six cylinder engine producing 230bhp, I'd have not connected it with the horrible, horrible 330i I had for twelve days before getting rid. It was hugely quick though, with improbable levels of very low down torque. Drove like a sodding great electric motor, but was less fun and used more oil!

[Peter Cobbold]

Peter, I wonder if valve overlap, and exhaust scavenging (pulses?) is what can lift N/A engines over the 100% mark? Forgive the basic terms: I'm only a metal basher.

Barry,

I think the variable valve timing will have contributed most. It can give a huge amount of of overlap at higher rpm allowing scavenging and resonant tuning of the intake. If the BMW engine has a 'Helmholz resonator' in the intake duct, thats' how its done. Its a pity we have lost the one acoustic expert who could give a much better explanation: its all about sound waves.

 

Sorry I cant answer your original question. My guess would be to focus on intake - cam and filter - before the exhaust. Because there's plenty of pressure to force the exhaust gas out but only 14.7psi to push it in. What you need is someone to post a before and after measurement on a rolling road, where the only change was the ex manifold. On the other hand, Gareth's earlier data on losses in the standard cross-box silencer is worth following up, and maybe easier/cheaper to improve.

 

Peter

[TriumphV8]

 

Oh yes, don't let me stop the side debates: they've been fascinating, and judging by the thread hit rate, it's not just me that thinks so.

 

Unfortunately in the first thread some interesting points for and against that manifold popped up.

This is gone now if the Mods will not set back to the state before it all became very personal.

 

Don't know how others being involved here see the discussion but I like to see arguments for and against

and have an interesting discussion and that all can be done in a way

that we can still meet for a coffee maybe at Stoneleigh.

[Peter Cobbold]

Peter

Then explain to us all how I had a 1300 cc escort rally car 20+ years ago engine built by QED and dyno at one the most respected engine tuners ever ( no name mentioned) gave 137 bhp at 6200 rpm. To give you some idea http://www.burtonpower.com/tuning-guides/tuning-guide-pages/ford-kent-crossflow-tuning-guide.html

Neil,

For all you tell us it must be magic.

How was it done? we're here to listen and learn.

Peter

[Alec Pringle]

Hi Andreas,

 

I've been a Forum viewer since its inception.

 

Moderators do not remove posts wholesale on their own initiative, that has never happened before. They only moderate contributions which are grossly offensive or potentially libellous, in the interests of abiding by the law of the land and enabling this Forum to continue to thrive.

 

Sanctions have been applied to individual contributors in only a small number of instances. In some cases the individual contributor concerned has then taken umbrage, and requested that all his posts be removed forthwith, unwilling to continue sharing his pearls of wisdom with the rest of the Forum community. His posts have then been deleted in their entirety, as requested.

 

I'd guess that is again the case here - the moderating team might be able to confirm that ?

 

At the risk of stating the obvious - the TR Register membership democratically elects a Board of Directors. These directors democratically determine the ground rules for Forum, in conjunction with the Forum administration and moderation team. We, the individual contributors, agree to abide by those relatively minimalist rules, guidelines more like, in return for enjoying the privilege of belonging to the Forum.

 

It is unfortunate when someone's contributions have to be removed en masse, but it's a toys and prams question. All too often that small number of individuals can be identified as also having had differences of opinions with other Forums. Not everyone wishes to abide by the general rules of civilised life and democracy.

 

Cheers

 

Alec

[Guest ntc]

Neil,

For all you tell us it must be magic.

How was it done? we're here to listen and learn.

Peter

Peter

Read Toms reply, it's called L.s.d no magic involved or bolt on hair dryers

[Guest ntc]

Barry

Yes it will do 150/160 bhp.

[Peter Cobbold]

Thanks Neil,

That's very helpful for those of us who want to learn.....

....how not to be ripped off .... nor to believe the implausible.

 

In the absence of information I conclude that 230bhp at 6000rpm from the 2.5TR engine really is fiction.

Fuel flow and AFR measurements will nail the discussion.

"End of".

 

Peter

[Tom Boyd]

That's correct. We have seen more that 230 bhp!

 

It's rather simple really, a very well put together engine with the right bits inside and set up correctly.

 

Best not tell you we are seeing over 220 with the 4 cyl engine.........

 

 

Tom

[GT6M]

Peter

Then explain to us all how I had a 1300 cc escort rally car 20+ years ago engine built by QED and dyno at one the most respected engine tuners ever ( no name mentioned) gave 137 bhp at 6200 rpm. To give you some idea http://www.burtonpower.com/tuning-guides/tuning-guide-pages/ford-kent-crossflow-tuning-guide.html

Simple, its a short stroke motor, with a much bigger cylinder { wider } than a 2.5

so the valves are not shrouded as much., esp if its a flat heed too.

besides, that sort of power was coming frae the last works Spittys too.

 

a short stroke will always rev faster, and higher than a long stroke,

and have less frictional losses

 

And to collude wid Peter, i,ll add that the frictional losses at 6500+ will be immense,

this is another reason that im skepticl of 245 hp

 

But for some clarity, some info on

comp ratio,

valve timings

lift

rocker ratios,

bore size,

crank throw

 

some how, i dont think this is a 2.5, but mebe 2.8-9,even 3.0L

if bores have been shifted aboot, and a diff crank used,!!

 

pray tell, { with oot giv,n yer secrets away }

 

M

Edited January 14, 2015 by GT6M

[Guest ntc]

That's correct. We have seen more that 230 bhp!

 

It's rather simple really, a very well put together engine with the right bits inside and set up correctly.

 

Best not tell you we are seeing over 220 with the 4 cyl engine.........

 

 

Tom

Peter

You ever seen a Tr 6 pot engine with equal space between the cylinders ?

[Tim D.]

Sort of agree with Peter and GT6M.

Giving no practical details of how such outputs were gained from a triumph 6 is at best frustrating.

Using phrases like "l.s.d and no magic" and "It's rather simple really, a very well put together engine with the right bits inside and set up correctly." Are at best frustrating and at worst patronising.

In my view, no data, no details equals no credibility.

Please please share your secrets.

Cheers

Tim ( annoyed)

[GT6M]

Peter

You ever seen a Tr 6 pot engine with equal space between the cylinders ?

 

Ahhaa, im reet on the LooT then, !!

 

its deffo not a 2.5, cats slowly coming oot the bag.

 

to be honest with the Perpetrators of 245 hp, shame on the lot of ye for telling Porkie Pies

2,5 my arshe ole

 

And , GT did this yonks ago, all beit on a 2L to mek 2.3, or a little moer

So, copying GTs work, or thinkings noo ,!!

M

Edited January 14, 2015 by GT6M

[Guest ntc]

Your wrong.

[GT6M]

On what, GTs job, or my thoughts as to engine size

if bores have changed, then so has capacity

M

[Barry911]

Neil, thanks for confirmation.

 

Peter, thanks, will focus on in rather than out!

 

Alec: all wise words indeed, and I have the utmost sympathy and respect for the moderators, who I think in this case are doomed either way.

 

Tim: so agree! In fact, couldn't agree more ....

[Ragtag]

Hi Andreas,

 

I've been a Forum viewer since its inception.

 

Moderators do not remove posts wholesale on their own initiative, that has never happened before. They only moderate contributions which are grossly offensive or potentially libellous, in the interests of abiding by the law of the land and enabling this Forum to continue to thrive.

 

Sanctions have been applied to individual contributors in only a small number of instances. In some cases the individual contributor concerned has then taken umbrage, and requested that all his posts be removed forthwith, unwilling to continue sharing his pearls of wisdom with the rest of the Forum community. His posts have then been deleted in their entirety, as requested.

 

I'd guess that is again the case here - the moderating team might be able to confirm that ?

 

At the risk of stating the obvious - the TR Register membership democratically elects a Board of Directors. These directors democratically determine the ground rules for Forum, in conjunction with the Forum administration and moderation team. We, the individual contributors, agree to abide by those relatively minimalist rules, guidelines more like, in return for enjoying the privilege of belonging to the Forum.

 

It is unfortunate when someone's contributions have to be removed en masse, but it's a toys and prams question. All too often that small number of individuals can be identified as also having had differences of opinions with other Forums. Not everyone wishes to abide by the general rules of civilised life and democracy.

 

Cheers

 

Alec

 

Sorry Alec but Andreas was referring to the original Exhaust Manifold thread which was pulled in its entirety, long before Gareth was banned. That was why Barry started the Mk2 thread. The fact that Gareth has since requested all his content to be removed (assuming that is what has happened) is irrelevant to Andreas' original point.

 

I do think it is a shame that GT couldn't play within the rules but I also suspect that his reputation proceded him.

[Tom Boyd]

Gentleman,

 

In no way was I being patronising.

 

I shall bow out of this discussion, I feel it can only end in tears.

 

Tom

[Guest ntc]

Go much over + 40 and you will have head gasket failure,figure that one out.

[Guest ntc]

Gentleman,

 

In no way was I being patronising.

 

I shall bow out of this discussion, I feel it can only end in tears.

 

Tom

Me too had enough.

[Peter Cobbold]

Peter

You ever seen a Tr 6 pot engine with equal space between the cylinders ?

..............in order to raise the bore and cubic capacity.

If its bored to give 3000cc then the VE has to be as in post #55, about 112%

That is just about believable, taking into account errors in measurement and in calculation.

But its not a 2.5 engine.

Peter

[Alec Pringle]

Hi Chris,

 

I suspect you mean preceded him ?

 

You may not have been around the first time that Gareth crossed swords with the Forum administration, a good few years back now, but it's not as if this was the first difference of opinion. Unfortunately not a lot seemed to have been learned from the previous exercise . . . . .

 

Yes I realised what Andreas was referring to, and my points related both to that and to the subsequent larger moderating. We have in the past seen an entire thread removed because of one contributor's input, and that contributor's reaction to moderating input.

 

The real problem here is that a responsible forum needs to be self-policing, and that requires all of us to apply due diligence to our contributions. We'll all make mistakes from time to time, no problem, to err is human. It does become a problem when one individual declines to accept the agreed norms, and repeatedly steps over boundaries in wilful fashion for his own reasons. It's even more galling if the overstepping of the mark is (at best) tangential rather than directly related to the topic, and in no sense with the club's interests in mind.

 

And yes, it's even more frustrating when thought provoking discussion is curtailed as a result.

 

Just my personal thoughts, of course.

 

Cheers

 

Alec

Edited January 14, 2015 by Alec Pringle

[Ragtag]

Hi Chris,

 

I suspect you mean preceded him ?

 

 

Yes I did. Unfortunately my 'spell checker' auto corrected(sic)