Peter Cobbold Posted January 10, 2015 Report Share Posted January 10, 2015 Move house Yeh, might be safer not to be too close: http://notolyganuchaf.co.uk/images/IMG_2321.jpg This machine had gearbox failure a few years previously. Another of these machines caught fire a few years back. Luckily the flaming debris didnt fly into the nearby forest. FB could only stand by and watch it burn out. Moving house can be risky as the things are popping up everywhere.The flatter the terrain the better.... Peter Quote Link to post Share on other sites
Peter Cobbold Posted January 11, 2015 Report Share Posted January 11, 2015 Gareth, More measurements! great, thank you , bookmarked. Interesting that the 30C and 20C curves diverge, percentage-wise, more at high rpm. So at top rpm the difference is 15 off 145 while at mid-rpm about 4 off 80. Thats 10.3% and 5% respectively. I wonder why? Is it that the fuel has longer to evaporate in the runners at mid rpm so increasing density? Even so I'd have thought the fuel evap cooling would have the same ca 18C cooling effect on density at both 20 and 30C ambient, so the percentage would not change. So although that might improve charge density at mid rpm compared with high rpm, it wont explain the 20 vs 30 difference. Theres a big drop - 20% - in air viscosity between 20 and 30C, but I cant see where that could make a difference, there's no shear effects in the system, I think. Peter Quote Link to post Share on other sites
roy53 Posted January 12, 2015 Report Share Posted January 12, 2015 (edited) There you go Roy time for him to come over here and see what a weber powered car can do. For info only not to stir things up. TR6 cyl dyno figures max lb ft 202 at 6000 bhp 230 197 at 6500 245 178 at 7100 241 this is not the over bored 6 cyl which i assume gain a bit more.it is running on webers . This was on the dyno using their exhaust set up , i had hoped to have it tested with the exhaust manifold that i had built but was not available in time. have seen this tested on 4 cylinder tr engines and there was a definite gain when they worked on the various manifold options available at that time especially on 91mm bore when they built a longer manifold.This did not make any difference on the 89mm engine though. It would be good to see the results of this sort of back to back test carried out on a 6 engine set up on a dyno . To GTT things may have moved on since you worked on 6 cyl engines as figures 250/265 bhp are being found [on webers ].Yes the fan belt problem i mentioned was at +7000 and yes they were/are turning over. The electronic pumps are being tried but there is concern that it could heighten the problem with the cold spot in the block which you indicated upon due to the design. I am finding a lot of useful info in this topic to be thought over so keep it coming. ROY Edited January 12, 2015 by roy53 Quote Link to post Share on other sites
Peter Cobbold Posted January 12, 2015 Report Share Posted January 12, 2015 (edited) Roy You understate one of your hp: 6000 rpm and 202 ft.lbs = (202x6000)/5250 = 231 hp That means your engine produces around 40-50% more torque, at same rpm, as a standard 150hp PI engine. That's very difficult to believe for a n/a engine. It means it has to breathe in 40- 50% more air on each stroke. Now if it were supercharged, yes that's possible. But not from sucking air I think. Peter Horsepower = Torque x RPM/5252. Its a fixed relationship. Torque is 'force x distance', units of ft.lbs. Edited January 12, 2015 by Peter Cobbold Quote Link to post Share on other sites
roy53 Posted January 12, 2015 Report Share Posted January 12, 2015 correct Peter, typing mistake should have been 230 bhp. Have edited my post to correct .thanks ROY Quote Link to post Share on other sites
Peter Cobbold Posted January 12, 2015 Report Share Posted January 12, 2015 (edited) Roy, If the dyno were relatively modern and so calibrated in N.m then a reading on the machine of 202 in N.m is actually 149 ft.lbs ** That works out at (149 x 6000) / 5250 = 170hp. 170hp at 6000rpm is more believable than 230 hp. Peter ** http://www.convertunits.com/from/N+m/to/ft+lb Edited January 12, 2015 by Peter Cobbold Quote Link to post Share on other sites
GT6M Posted January 13, 2015 Report Share Posted January 13, 2015 lb ft 202 at 6000 bhp 230 197 at 6500 245 178 at 7100 241 ?? Untill I can read the RR charts, engine specs, cam, CR, ect ect, im with Peter on this one,. Wheres Gareth when he,s needed, !! M Quote Link to post Share on other sites
Wayne Scott Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) A note regarding a recent removal of topics from the forum. The moderating team have been concerned for sometime about the post content of a particular individual who, despite offering some interesting technical contributions, repeatedly posted potentially libellous comment referring to both individuals and commercial concerns. This represented a potential risk that we are unable to allow to continue for the safety of this forum, it's users and the TR Register car club. The contributor in question had been approached on numerous occasions via email and private message to explain the rules of the forum and to request they modify the content of posts going forward. Sadly the contributor refused and in fact became quite aggressive towards the team of volunteers that give their time to ensure the smooth running of this forum. This left the moderators with no other option than to remove the libellous posts and issue a ban, a move that is never taken lightly and is always used as a last resort. The contributor has been contacted regarding this and given the opportunity to appeal in writing to the TR Register office. At request of the user - all the posts by the banned account have been removed. Please would all users familiarise themselves with the rules of the forum and the meaning of the terms issued within to ensure we have a safe and pleasant forum on which to exchange help amongst TR owners. I hope this thread can now continue to answer the original question regarding Exhaust Manifolds. Regards, Wayne Scott Press Officer , TR Register. Edited January 14, 2015 by TR_Register_Press update to situation Quote Link to post Share on other sites
Tom Fremont Posted January 13, 2015 Report Share Posted January 13, 2015 I can well appreciate the move to ban the individual in question. We should not succumb to the notion that knowledge specific to our, or any other particular interest is the exclusive province of negative persons. Interestingly, we have a counterpart to that offender in the 'States, who, rather than plaguing the forum(s) does a trade in specialty components where he abuses his clientele mercilessly - yet no matter how much bad press he receives in the forum(s) anecdotally they continue to flock to him; this I surmise is due to falling for the above notion . Quote Link to post Share on other sites
Peter Cobbold Posted January 13, 2015 Report Share Posted January 13, 2015 Slippery slope.... Anyone who wishes to remain in touch and continue learn from this engineer's expertise PM me. Peter Quote Link to post Share on other sites
peejay4A Posted January 13, 2015 Report Share Posted January 13, 2015 For my part I think that's over-moderation. Quote Link to post Share on other sites
Alec Pringle Posted January 13, 2015 Report Share Posted January 13, 2015 Absolutely Peter, censorship in any form is a slippery slope. In years gone by I have occasionally disagreed with over-enthusiastic PC moderating, but over the past couple of years we seem, as far as I've been able to see as an ordinary member, to have enjoyed a sensibly liberal and robust regime. I can only think of a handful of folks who have been a tad OTT in their comments, and who would appear to have had their posts edited - and presumably knuckles gently rapped, or whatever in response ? No problem, we can all be out of turn occasionally. GTT has been barred from this Forum in the past, quite a few years ago now, for his outspoken comments. As far as I'm concerned, anyone can call me all the names under the sun if they wish, no problem, water off a duck's back. I'm sure most of us are just as resilient ! It's a different matter when a contributor starts slagging off individual commercial specialists or commercial concerns. Factual chapter and verse in respect of a specific instance of a supplier and/or component problem is one thing, Generalised pejorative comment, presumably stemming from whatever personal historical circumstances, is quite another. Like it or not, the laws of libel in the UK are remarkably wide in their scope - and the content of social media comes under increasing scrutiny. This is still an area of legal exploration, and the ground rules are hardly cast in stone - laws of libel tend to relate more to the age of the printed word rather than the computer screen. We've all seen in the media that the law is increasingly being used to curtail unacceptable comment or statements on social media generally - whether in the context of racist expression or in some instances contempt of court. There have been libel cases resulting from internet publication, and there have been Forums and their hosts crippled by legal action in respect of defamation or libel. This is a car club Forum, primarily for club members and generously opened up to a world wide community of TR enthusiasts. It would be a bloody shame if the utterances of one individual, not even a member of the TR Register, kicked our Forum into touch. Bottom line, if one individual contributor with a commercial interest has issues of some description with A N Other commercial concern/s, current or historical, then this is not the place to air those supposed grievances. The quality of technical content does not override the requirement for normal courtesy. From what I have read in some of GTT's past (and subsequently edited or removed by mods) postings, then if I was a moderator I'd be getting somewhat upset too - and I can't imagine that a ban has been imposed without at least some prior discussion with the individual concerned. Our Forum rules are hardly draconian, and the warning point system is there as a starter for ten, so I'd guess in this instance that diplomacy failed to achieve a reasonable result ? I should add that some of the posts to which I refer disappeared pretty quickly, and I doubt that many regular viewers had the opportunity to peruse the offending content. Much as I dislike any form of censorship, sadly in this instance I have to agree with the moderators - the contributor has brought the situation upon himself. Cheers Alec Quote Link to post Share on other sites
JohnG Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) All As a relatively new reader and occasional user, of the forum I have been amazed at 1) the depth of knowledge that the likes of Peter and Gareth have, on a wide range of Engineering topics and 2) their willingness to spend time sharing their knowledge with the TR community. I have also been surprised at the sometimes, strong language used on the forum, something that must not be allowed to continue. Like many, I was not offended. I know my limitations and none of the language was aimed at me, but, as Alec so clearly says I would imagine that legally, the forum was treading a fine line. Personally, I will miss the tennis like toing and froing of Engineering know how we have been privilaged to be able to read. Edited January 13, 2015 by wjgco Quote Link to post Share on other sites
roy53 Posted January 13, 2015 Report Share Posted January 13, 2015 PETER The figures that i quoted were taken straight from the dyno print out chart. Begin to wish i had not bothered. ROY Quote Link to post Share on other sites
Alec Pringle Posted January 13, 2015 Report Share Posted January 13, 2015 I'm sure we'll all miss the techno engineering banter, even if some of it did come into the escapee from pseud's corner or bullship baffles brains category. Just my view, of course. Unfortunately the potential risk factor presumably wasn't worth the candle. I was going to suggest the Sideways forum, as that is where GTT used to hang out regularly, but his postings seem to have dried up . . . . in somewhat acrimonious style. http://sideways-technologies.co.uk/forums/index.php/user/701-gt/ It all seems a tad odd. Such is life. Cheers Alec Quote Link to post Share on other sites
Guest ntc Posted January 13, 2015 Report Share Posted January 13, 2015 PETER The figures that i quoted were taken straight from the dyno print out chart. Begin to wish i had not bothered. ROY Roy You know it as do I.Just leave them to it. Quote Link to post Share on other sites
Tom Boyd Posted January 13, 2015 Report Share Posted January 13, 2015 Roy's figures are realistic We are regularly seeing that kind of power and more..... I await the slating..... Tom Quote Link to post Share on other sites
Peter Cobbold Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) Roy, Neil, Stiggy, I had my reasons for doubting: Air required is 1.5 cfm per horsepower ( http://www.sdsefi.com/techform.htm ) Hence 230hp needs 345cfm = 9,770 litres per min 6000rpm so 3000 x6 = 18,000 intake strokes per min So volume normal air per intake: 9770/18,000 = 0.54litre. So 540ml air at atmospheric pressure per intake stroke is needed to make 230hp at 6000rpm. Is that feasible? Cylinder capacity 2500/6 = 416ml So the volumetric efficiency = 540/416 = 130% Even if 2.7 litres displacement the VE has to be 540/450 or 120% Do tell us how its done. Peter For the sceptics. A VE of 130% means there is 30% more air in the cylinder than if it were equilibrated with atmospheric pressure. There can be no losses anywhere, in carb, butterfly, ports,valves. The air pressure has to be fully equilibrated. And then 30% more has to be squeezed in. Edited January 13, 2015 by Peter Cobbold Quote Link to post Share on other sites
Tom Boyd Posted January 13, 2015 Report Share Posted January 13, 2015 Done with effort and engineering. Either on webers or injection. Not a problem. Quote Link to post Share on other sites
Ragtag Posted January 14, 2015 Report Share Posted January 14, 2015 (edited) Roy, Neil, Stiggy, I had my reasons for doubting: Air required is 1.5 cfm per horsepower ( http://www.sdsefi.com/techform.htm ) Hence 230hp needs 345cfm = 9,770 litres per min 6000rpm so 3000 x6 = 18,000 intake strokes per min So volume normal air per intake: 9770/18,000 = 0.54litre. So 540ml air at atmospheric pressure per intake stroke is needed to make 230hp at 6000rpm. Is that feasible? Cylinder capacity 2500/6 = 416ml So the volumetric efficiency = 540/416 = 130% Even if 2.7 litres displacement the VE has to be 540/450 or 120% Do tell us how its done. Peter For the sceptics. A VE of 130% means there is 30% more air in the cylinder than if it were equilibrated with atmospheric pressure. There can be no losses anywhere, in carb, butterfly, ports,valves. The air pressure has to be fully equilibrated. And then 30% more has to be squeezed in. Peter, Whilst it is easy to be sceptical about horsepower claims that are outside most people's experience with these engines your reasoning (if I understnd it correcty) must be flawed also. The implication of your maths suggests that the horsepower of an engine is limited by its displacement (100% VE). My gut instinct is that can't be right but I confess I don't know why! Edited January 14, 2015 by Ragtag Quote Link to post Share on other sites
TriumphV8 Posted January 14, 2015 Report Share Posted January 14, 2015 A VE of 130% means there is 30% more air in the cylinder than if it were equilibrated with atmospheric pressure. There can be no losses anywhere, in carb, butterfly, ports,valves. The air pressure has to be fully equilibrated. And then 30% more has to be squeezed in. At my Megasquirt calculations are done based on cylinder volume and injector fuel amount. Tried to set that up properly to the data printed on the injector and than carefully looked after in the BOSCH tables. From that with some flaws because absolute precision is not relevant for metering I come to a VE up to 95 in some areas. 130 would be very nice but even if I take the plenum and filter off I will not reach 100. Maybe there can be some details brought to the public like Neil did on the TR6 head at Sideways. Quote Link to post Share on other sites
Peter Cobbold Posted January 14, 2015 Report Share Posted January 14, 2015 (edited) Peter, Whilst it is easy to be sceptical about horsepower claims that are outside most people's experience with these engines your reasoning (if I understnd it correcty) must be flawed also. The implication of your maths suggests that the horsepower of an engine is limited by its displacement (100% VE). My gut instinct is that can't be right but I confess I don't know why! Chris, The VE at any one rpm is limiting. Because VE dictates torque and that is multiplied by rpm to get hp. If we redid those calcs at higher rpm then we might find a point where 230hp was achievable with a VE that is beleivable, say 90% at some higher rpm. Fabled engines that reach 100bhp per litre need high rpm: I dont know of one n/a engine that reaches 100bhp/litre at 6000rpm. That's becasue its VE would have to be far higher than the laws of physics allow. Peter Edited January 14, 2015 by Peter Cobbold Quote Link to post Share on other sites
Peter Cobbold Posted January 14, 2015 Report Share Posted January 14, 2015 (edited) At my Megasquirt calculations are done based on cylinder volume and injector fuel amount. Tried to set that up properly to the data printed on the injector and than carefully looked after in the BOSCH tables. From that with some flaws because absolute precision is not relevant for metering I come to a VE up to 95 in some areas. 130 would be very nice but even if I take the plenum and filter off I will not reach 100. Maybe there can be some details brought to the public like Neil did on the TR6 head at Sideways. Andreas, You beat me to it. I was going to suggest a cross-check on bhp figures - a check on the rolling road - by measuring fuel consumption and AFR while recording hp. That then gives a measure of the air consumption and the actual VE can be calculated. Peter Edit: thinking more, we dont actually need the rolling road. Measure fuel flow at wot and fixed rpm while driving, and AFR with a UEGO in the exhaust. That tells us how much air was mixed with the measured fuel flow and hence we can get to find VE. (Providing all the fuel is burned properly with no misfiring). Edited January 14, 2015 by Peter Cobbold Quote Link to post Share on other sites
Guest ntc Posted January 14, 2015 Report Share Posted January 14, 2015 (edited) 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 Edited January 14, 2015 by ntc Quote Link to post Share on other sites
Barry911 Posted January 14, 2015 Author Report Share Posted January 14, 2015 Roy, Neil, Stiggy, I had my reasons for doubting: Air required is 1.5 cfm per horsepower ( http://www.sdsefi.com/techform.htm ) Hence 230hp needs 345cfm = 9,770 litres per min 6000rpm so 3000 x6 = 18,000 intake strokes per min So volume normal air per intake: 9770/18,000 = 0.54litre. So 540ml air at atmospheric pressure per intake stroke is needed to make 230hp at 6000rpm. Is that feasible? Cylinder capacity 2500/6 = 416ml So the volumetric efficiency = 540/416 = 130% Even if 2.7 litres displacement the VE has to be 540/450 or 120% Do tell us how its done. Peter For the sceptics. A VE of 130% means there is 30% more air in the cylinder than if it were equilibrated with atmospheric pressure. There can be no losses anywhere, in carb, butterfly, ports,valves. The air pressure has to be fully equilibrated. And then 30% more has to be squeezed in. 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. Quote Link to post Share on other sites
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