kjp Posted April 12, 2005 Share Posted April 12, 2005 245bhp @ 7223rpm (nice and low) and 183lbft (Wow). Wow indeed. 16.5 bar BMEP peak torque and 16.0 bar BMEP at peak power. I don't believe anybody has claimed this performance from an NA engine .....ever!! I think I would be checking the Dyno Calibration Ken P Link to comment Share on other sites More sharing options...
tom7 Posted April 12, 2005 Share Posted April 12, 2005 There are at least half a dozen 1900K's that have returned 245bhp taken on both emeralds and Mech repairs RR's. I can't remember the equation for BMEP but these outputs seem to be entirely consistent with big bhp XE's, Duratecs and others. Link to comment Share on other sites More sharing options...
Myles Posted April 12, 2005 Share Posted April 12, 2005 DW mentioned that Niges torque was right at the (theoretical?) limit - so for the same figure to come out of two different RRs seems entirely reasonable. Project Scope-Creep is underway... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
V7 SLR Posted April 12, 2005 Share Posted April 12, 2005 Mine was at 178lbft though. Link to comment Share on other sites More sharing options...
oilyhands Posted April 12, 2005 Share Posted April 12, 2005 I think there may be a scaling problem with Alex's engine, if the roller speed is not accurately synched with the engine speed than the torque can be skewed up or down as a result. It owuld only take a 3-5% innacuracy in the MPH/RPM factor to skew the results up from mid 170s to 183. The BHP would remain the same. That may explain why the BHP figure is shown at a relatively low RPM figure. I think 183 is above the envelope for pump fuel on that type of engine. Oily Link to comment Share on other sites More sharing options...
kjp Posted April 12, 2005 Share Posted April 12, 2005 So V7's engine made 15.9 bar BMEP at peak torque which is in line with the 'best engines' quoted and I believe Peak power was at 7900rpm which is 14.5 bar BMEP. An R500 achieves 13.3 bar BMEP at peak power A CSR260 achieves 13.5 bar BMEP at peak power I struggle to believe that an engine can come out of the box 10~20% better than anything that has come before it. 130hp/l is impressive enough but at 7200rpm?? Link to comment Share on other sites More sharing options...
V7 SLR Posted April 12, 2005 Share Posted April 12, 2005 You're confusing me with your line of argument there Ken. I struggle to believe that an engine can come out of the box 10~20% better than anything that has come before it.What did you mean by that? What engine is "out of the box"? Link to comment Share on other sites More sharing options...
oilyhands Posted April 12, 2005 Share Posted April 12, 2005 KJP, Like I said, I believe that there is a scaling issue with Alex's engine, such that the reported RPM is lower than actual RPM. The will skew the torque upwards and give peak power at an RPM lower than actual. In terms of specific output per litre the engine is less powerful than Peter Carmichaels (1800), Mick Smiths (1800), Andrew Dents (1800) to name a few and Mike Bees's (1700) and Mark Bishops (1700). None of these engines are 'out of the box', they are the end result of a long development program stretching over 6-7 years which has encompassed just about every aspect of the engine. The imprtant thing here is not the *absolute* figure which may or may not be 245BHP, but the comparative figure with other engines run on the same RR which gives a very real idea of the engines potency compared to others. When Peter Carmichaels engine was run against an R500 on the same RR on the same day it comprehensively trounced it, peak power was 8% higher and peak torque was 9% higher. In some places on the torque curve Peters engine was 30lb/ft ahead. Oily Edited by - oilyhands on 12 Apr 2005 23:02:02 Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 12, 2005 Share Posted April 12, 2005 Well, Mick S is working hard on the piston pocketing etc and hopes to have the car at the Ringlestone Inn (Kent and East Sussex L7C meeting) THIS Thursday. Fingers crossed! Link to comment Share on other sites More sharing options...
Johnty Lyons Posted April 13, 2005 Share Posted April 13, 2005 And as soon as he gets it running reasonably I'll have a base map i can use and then i'll be running as well. It's just sliughtly harder for me to get to Emerald than the rest of you ☹️ Link to comment Share on other sites More sharing options...
Graham Perry Posted April 13, 2005 Share Posted April 13, 2005 Peter C will be pleased to know that his engine is still the one by which the others are being measured Link to comment Share on other sites More sharing options...
Peter Carmichael Posted April 13, 2005 Share Posted April 13, 2005 Oily has cleverly disguised a good point. My engine was only ever run on the Emerald Brixton rolling road, which is now generally accepted to have given slightly high numbers. The comparison runs from that RR show that it was a belter of an engine, significantly better than the factory options of the time and with no nasties in the power delivery. It also stood up well to comparison to Graham Ford's 2.1 XE at the time. I suspect that the 1.9 Ks making 245bhp on the new Emerald RR are probably a close (if not exact) match for my engine as it was. Leading me to ask Oily whether I'm approaching the front of the queue yet...? Link to comment Share on other sites More sharing options...
oilyhands Posted April 13, 2005 Share Posted April 13, 2005 Hi Peter, I was waiting for a sign.. You are now near the front of the queue, give me a call to discuss full spec.. Oily Link to comment Share on other sites More sharing options...
SteveB Posted April 13, 2005 Share Posted April 13, 2005 Johnty, You may find that my map will be good for you to use. I have the same induction (inc trumpet lengths) as V7, a very similar dimensioned manifold compared to that which Nige has (AFAIK). My head has slightly larger ports due to the bigger inlets I have, but not much more, so I suspect my map would be a good starting point - what do you think Oily? When mapping we didn't need to add much fuel if any, just adjust my 1.8k map slightly. I'm running my original 234cc injectors at 3.9bar. It surprised me that I didn't need to fit the bigger injectors I'd brought along to Emerald. DW said somewthing along the lines of "I think the 1.8 was just p*ssing the fuel out of the exhaust and the 1.9 is letting it all burn". DW has a copy of my map that I'm sure he'll email if you want to try that one Johnty, or I can download it tonight. Nige, I've not looked at Mick's piston damage yet, but mine was quite minor compared to that you describe above. But my head was a fresh one that hadn't been skimmed to within an inch of its life. After the contact I called scholar and spoke to their engine builder and he told me that with a heavily skimmed head even the 32.5mm valves may touch - they had on his own engine.....I guess the wayfor you to tell will be to compression check your engine, but given the results you've had I''d say that you don't have any bent valves... SteveB Edited by - SteveB on 13 Apr 2005 09:35:07 Link to comment Share on other sites More sharing options...
kjp Posted April 13, 2005 Share Posted April 13, 2005 Sorry Oily I wrote my last reply as you were responding, so we overlapped. I also apologise for the term 'out the box' I understand that the numbers are comparitive but I think we do occasionaly need a reality check. I just worry quoting so much power at such a low speed makes everybodies previous efforts seem poor and makes it pretty difficult for the next man to come anywhere near!! Do we have any feeling for the Actual peak power speed of this engine. V7, I use your engine as a comparison as it falls into line with the very best of the other engines we have seen and this engine is significantly better Thanks for the clarfication Ken Pendlebury Link to comment Share on other sites More sharing options...
V7 SLR Posted April 13, 2005 Share Posted April 13, 2005 Comforting words Steve... keep 'em coming. 😬 IIRC my head's only ever had one 20thou skim right after DVA did the original porting. Can't say whether Minster ever skimmed it of course but I shall put it out of my mind until such a time comes that I can borrow an endoscope (I know a chap who has one). I'm running on massive injectors but still at 3 bar. I have wondered (a few times) whether I should have left the originals in place and gently crushed the FPR. Seeing how one of my locals has successfully done this I am now convinced that I should have. My injeectors are waaaay too big and are right on the (min) limits at idle. I've recently been pointed towards some nice ones in the States which appear about the right size and are matched. I've got a wideband lambda now (actually I don't because I've loaned it to a friend) so all I need is the new Emerald software and I can tune new injectors in myself. Link to comment Share on other sites More sharing options...
Johnty Lyons Posted April 13, 2005 Share Posted April 13, 2005 Iam running the Blue VX injectors that Mick has on a Bernard alloy manifold which has the bell mouths right out at the bonnet line. Std FPR and Std Catermam 4:1 comp manifold So am a bit unsure of whose base map to use I'll gladly accept all of them and have a play to see how she goes Just got my new CF cam belt cover last night so all systems are now on GO. Link to comment Share on other sites More sharing options...
oilyhands Posted April 13, 2005 Share Posted April 13, 2005 Ken, The previous power trace I saw for Alex's engine saw it still climbing at 8K, hence his desire for a higher RPM run/mapping session. The final power curve shows it peaking at 7200-7300 which doesn't stack up. Experience with those cams shows that peak power normally occurs at or near 8000 with the power trailing off slowly after that, on 1800s the peak is 2-300RPM higher. My guess is that Alex's engine is peaking nearer 8000 and as a result the torque figure is skewed a bit above the real figure. If you do some simple maths based on that guesstimate then the torque looks more realistic. If we guess that the true peak RPM is 7800 then we have a 7.5% error in scaling, apply this to the peak torque of 183 and we have a more realistic 170lb/ft which is more in line with previous incarnations and towards the upper limit of what is possible. Similary the peak BHP torque is then around 164lb/ft still a little higher than expected at 96% of maximum where I would expect between 90 and 95%. Oily Link to comment Share on other sites More sharing options...
V7 SLR Posted April 13, 2005 Share Posted April 13, 2005 I've just ordered a set of injectors from here. They appear to be scaled exactly for the power output of my engine and they are cleaned and flow-matched. Ken, I re-read your original post and now understand what you intended. I haven't tried to analyse Alex's figures but I agree that the low revs at peak bhp seem inconsistent with others. I did note that Alex has had his engine mapped at a different RR to the other 1900's (because he runs an MBE ECU as opposed to the Emerald ECU that everyone else runs) and as such we'd expect inconsistencies. Alex has had two mapping sessions, the second one to address the lack of attention paid to speed sites above 8000rpm. After his first session he came away with a power/torque figure totally in line with those found at Emerald, only about 3% lower. It has been noted before that there is a belief that Mech Repairs' rollers consistently read about 3% lower than Emeralds' new rollers. In addition the charts from each RR matched with respect to the revs. Therefore I would have said it was reasonable to agree that Alex's engine was performing almost identically to the other 1900's we'd seen to date (and since, in fact). Alex's latest "disputed" result comes from yet another RR operator and is actually inconsistent with his original read-out. As I don't believe anything in his map has changed below 8000rpm, it is obvious that this latest RR is in fact incorrectly scaled as DVA pointed out. Adding 3% to Alex's original result puts his engine spot on with mine for power, and spot on top of Dave Jackson and Steve Butts for torque. I know this is cooking the books but I like the consistency of all these results. DW told me that my engine was making close to the theoretical maximum torque per litre for an I4 nat-asp engine. I am interested to learn what that theoretical figure really is. Anyone know? It makes analysing RR claims easier if you know the limits of "possibility". Link to comment Share on other sites More sharing options...
Peter Carmichael Posted April 13, 2005 Share Posted April 13, 2005 Nig, DW would have told you that you were near max theoretical torque per litre for a 4 valve per cylinder design - 96lbft/litre. It doesn't matter whether the engine is I4, V12 or 1 cylinder, long stroke or short stroke. On pump fuel, 96lbft/litre is pretty much it. Link to comment Share on other sites More sharing options...
Myles Posted April 13, 2005 Share Posted April 13, 2005 DW would have told you that you were near max theoretical torque per litre for a 4 valve per cylinder design - 96lbft/litre. He did... ..actually, ISTR he said it was slightly over - but perhaps his memory/maths were failing him Project Scope-Creep is underway... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
V7 SLR Posted April 13, 2005 Share Posted April 13, 2005 Thanks Peter. It was an emotional day. I thought he said in-line 4, but 4 valves per cyl also works for me. 😬 So, 178ftlb from 1886cc is 94.4ftlb/litre. Mmm.... it *is* close. I saw your request for a new head to DVA earlier... any plans you care to discuss here? I'm interested in your timescales and anything relating to specification you care to relate. Link to comment Share on other sites More sharing options...
Peter Carmichael Posted April 13, 2005 Share Posted April 13, 2005 Spec has been discussed with Oily. It is basically a rebuild of the previous spec with a change of inlet cam and the 28.5mm exhaust valves. Inlets will remain 32.5 and the block will remain the reinforced all steel 1.8. So in principle I am not messing up the formula that worked so well last time, but I am also not being drawn towards the 1.9 route because I have too much commitment to the 1.8. It will be an interesting comparison when lined up against some of these big hitter 1.9s. Link to comment Share on other sites More sharing options...
martinwhitcher Posted April 13, 2005 Share Posted April 13, 2005 Peter/Oily.... We look forward to seeing it ps. Very interesting thread Martin MW 51 CAT Superlight No.171 now know as:Superlight DVA 207 Link to comment Share on other sites More sharing options...
ian crocker Posted April 13, 2005 Share Posted April 13, 2005 How do these big power Ks perform across the finishing line at Curborough or at Santa Pod? Do the numbers give the speed that would be expected? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now