Gollum Posted January 22, 2012 Share Posted January 22, 2012 well i do in fact have some my road car ran 10.00 at 134mph i will post the time card later whis was with a 5s box and a 1000kg car it had 340kw Crank or wheel 340kw? If those weights are accurate (don't forget to add your weight, I've made that mistake), then you had roughly 414hp at the wheels on that day in those circumstances, which I feel roughly does match the claim of 340kw if that's flywheel, as that's 462HP. Now, if that's a NA L motor my hat is off indeed, and I'd certain want as much info as you're willing to provide. Is that the case? Was this a NA L motor? Quote Link to comment Share on other sites More sharing options...
PMC raceengines Posted January 22, 2012 Author Share Posted January 22, 2012 340 kw atw turbo L29 and it had 1020kg Quote Link to comment Share on other sites More sharing options...
260DET Posted January 23, 2012 Share Posted January 23, 2012 This has the potential to be an interesting thread if people relax and don't rush to do a kneejerk reaction to a claim that they think is unreasonable or even nonsense. It should be remembered that in the internet age consumers are bombarded with all sorts of claims from businesses and individuals from many different countries, not all of which are accurate or which we agree with. Power output claims are one of the big ones and one which I have good $ reason to be annoyed, at least, about. Peter, the OP here, is a full time race engine builder with proven results in a very competitive environment, no question about that. He is an ex Gibson Motorsport mechanic, Godzilla ring a bell? Tony has a good point with the Bonneville Z he is familiar with, it would be interesting to be able to take that further by eg comparing it's performance with others or working backwards to arrive at a Cd figure the Z would have to do what it did with the claimed power it had. If something like that is possible, I don't really know. Nothing more from me, just hope that this thread does not get shut down prematurely. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 23, 2012 Share Posted January 23, 2012 (edited) And again, I don't care what theoretical calculations on head flow say. The numbers for horsepower required at speed are well documented (and coincidentally matched within a few HP of our dyno testing) for our speeds at Bonneville. We run closer to a .38 cd, and had around 320 at the rear wheels. Burton had a Bone-Stock .465cd car and went within 0.125mph as we did, obviously he DID NOT have 330HP. Pete, you're claiming Rebello's 400HP claim is bogus---please sir do the math on my example. It's not going to go that fast with only 330HP! physically impossible. The stock Zed is drag limited in stock engine form. It's aero is only slightly worse than a 4x8' sheet of plywood or Splitwindow VW Kombibus. You're intent on saying it isn't possible. I am giving you third-party independent verification that indeed it is! Our ports on our engine were flowing 220/175 and made 320 to the rear wheels at 8250rpms. It jibes almost exactly with our calculated drag HP requirements of a two way average of 173.325 and a best mile at 176.006. That can be tailwind explained. It's scary close. There is no way the Rebello Motor in #7770 only made 320 "in a pinch"... If you would do the math on your own with the verifiable figures give you above, you can calculate damn close what that Rebello engine WAS, indeed producing. Edited January 23, 2012 by Tony D Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 23, 2012 Share Posted January 23, 2012 To Gollyms point of HP is HP, is what I was getting at by using drag figures and top speed. Drag race simulations I don't put a lot of faith in, they all peg me around 202hp in my stock 76... I don't think so! BUT... Top speed running on a closed course and calibrated traps show my HP to be EXACTLY (almost to the HP!) the 147 i previously dynoed the car at. Drag and top speed are very closely related, grip and many other factors that come int play on 1/4 mile cease to exist in that test. We all don't have that testing capability, but I do, which is why I'm interested in the claim that the 400hp engine only makes 290 when in fact the facts of the top speed test DEFY that statement. There is no way to "cheat" and arrive to a 173+ mph top speed in a stock bodied open-maw 240Z with ONLY 290 HP! it CAN'T happen. We did it in our car with a .38 cd. With the stock .465? No way. Like I said, the calculations will tell you the HP requirement to go that fast, and even if you use another frontal area published... It's well upwards of 330-340 HP! Quote Link to comment Share on other sites More sharing options...
PMC raceengines Posted January 23, 2012 Author Share Posted January 23, 2012 thanks mate im not trying to piss you guys of i just dont like bs hp figers as they are un realistic , a 400hp L 3L with 133hp per L is not real any where with a 2 valve head , in austraila we have a race class caled supercars 5L v8 chev and ford with 620hp at 7500 with 10.5 comp per L thats 124 hp and they cost 120k to build with canted valves and the best injection setups you will find any where , so for a L28 type engine to make more per L is not realistic . the best head i have ever tested was from a jap 10.9 sec drag car with 50mm carbs and 9300rpm 3.2L it made 347hp and we were stund it had 48mm valve that had been moved over and it flowed 243 cfm Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 23, 2012 Share Posted January 23, 2012 Nothing more disappointing than someone with a closed mind. It us capable to back calculate horsepower from drag coefficient, frontal area. Thanks for seeing the point of my posts 260DET. I've always found it a bit common to peddle ones wares by disparaging another's. All I ever asked for was he do the calculations before being so emphatic in his "impossibility" claims. I guess an 11,600 RPM L-2X Engine is impossible as well... Quote Link to comment Share on other sites More sharing options...
PMC raceengines Posted January 23, 2012 Author Share Posted January 23, 2012 Nothing more disappointing than someone with a closed mind. It us capable to back calculate horsepower from drag coefficient, frontal area. Thanks for seeing the point of my posts 260DET. I've always found it a bit common to peddle ones wares by disparaging another's. All I ever asked for was he do the calculations before being so emphatic in his "impossibility" claims. I guess an 11,600 RPM L-2X Engine is impossible as well... mate im the most open engine man it the word and very open to new things im not hear to sell any of my work as i have plenty on i just wont to shear and see whats out there i do beleve that rebello made one very mad engine for that car ,top job and well done i just dont think it was a cheap 3L stroker, the work that goes in to any proper race engine is not cheap and if they made 133hp pr L thats amasing Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted January 23, 2012 Share Posted January 23, 2012 To get back on topic I have seen several people want to put a double overhead cam set up on an L6 with no results. It would be neat if someone did but the cost is just too much. Between the 2 heads shown there are too many differences. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 23, 2012 Share Posted January 23, 2012 (edited) Wallace Racing Top Speed Calculator for Bonneville: 2400# (likely light, I'm sure Burton, like us added somewhere on the line of 300#+ for traction) Cd .465 F/A 22 Result: 370HP under the best conditions of traction.. Right in line with your claim of the claim elsewhere of 365hp for the 3.0 How do you reconcile these numbers, sir? I don't dispute your testing of the engine in your possession. What I do dispute is the backhanded manner in which you dismiss with caviler attitude even the possibility that is is a valid HP claim in light of the facts behind running at Bonneville and being powered by a "Rebello400"? This same calculator pegged our 2900# 76 280Z with Undertray and G-Nose ( .38 Cd, same frontal) at 311HP with our dyno then showing 317! Like I said: "Scary Close"... Edited January 23, 2012 by Tony D Quote Link to comment Share on other sites More sharing options...
PMC raceengines Posted January 23, 2012 Author Share Posted January 23, 2012 (edited) back on topic the head has worked but like you say there are lots of problems . like the oil retern ,i have made the drysump pump remove the oil from the rear of the head with a -12 fitting and this fixed the oil drama all water and bolts line up and it works ok , the reasion its not finnished is the cost and time i need to spend on it , i have been very bizzy with all the L28s i built in the last year .17 last year from a 1 man shop so time is not on my side Edited January 23, 2012 by PMC raceengines Quote Link to comment Share on other sites More sharing options...
PMC raceengines Posted January 23, 2012 Author Share Posted January 23, 2012 Tony like i said im just hear to look and see what is out there . If Rebello made 400 na hp engine with 45mm carbs that will be more than a record good luck to them . i will just build my motors and be quiet . Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 23, 2012 Share Posted January 23, 2012 Building motors and sharing your knowledge is appreciated. But I don't like negative marketing, or sweeping broad based characterisations based on one, or even a series of engines. I've worked with most major compressor OEM's, and can say the basic physical laws governing them are all the same. I will be very careful answering customers questions regarding marketing claims. I know knocking another's product will likely as not get you booted from a project. I'll Market on my strengths, and rely on others to do the same. I'll educate based on the facts as I know them, but unless I've been there and seen how they do it, I'm very reticent to place my methodologies or results to someone else's build. We had some vitriol here over someone with a street L24 making 300+ with many calling BS as "Race Engine Builders" weren't getting that kind of power...disregarding the obvious fact that you don't have to conform to formula or class rules when making a street engine! It was foolish and unproductive to argue the obvious success of the particular build. As was it unproductive to knock the original FYI in light if it's obvious success. Bring what you have to the table, it's more than welcome and interesting. But if there's knocking of another's product, in light of unanswerable queries, consider that indeed the best course is to stick with ones own wares and reserve comment on others. The reason I asked originally about your reasoning behind the choice of RB26 over RB25 heads is that your favourite US Engine Builder is in work on an RB25 Head setup... Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 23, 2012 Share Posted January 23, 2012 Tony like i said im just hear to look and see what is out there . If Rebello made 400 na hp engine with 45mm carbs that will be more than a record good luck to them . i will just build my motors and be quiet . I don't think any of us are asking you to be quiet, as we ALL would love to see that L3XDE(t) run! (including tony i bet) I think what we're getting to is that you've come on here and within 30 posts are trying to discount one of the best L engine builders in history who has plenty of records to prove their importance. As to making 133hp per liter, I don't think that's other/worldly at all. And a 2 valve engine isn't as inherently air flow limited as people seem to suggest. And regarding the NASCAR comparison, remember that they could make MUCH more power if they weren't limited to some of their rules. Although they're almost as technically advanced as F1 motors in some ways, their long stroke will always be a limiting factor for all out HP figures. You can see this in the trend of MotoGP over the years. Bore sizes in a cc class has increased and increased over the years while volumetric efficiency hasn't improved dramatically. F1 has a similar story, where VE hasn't changed more than 10-15% in the last 40 years, yet HP per liter has increase DRAMATICALLY. Just some food for thought. Quote Link to comment Share on other sites More sharing options...
PMC raceengines Posted January 23, 2012 Author Share Posted January 23, 2012 OK sorry if we got of on the wrong foot . Now the rb25 head is as good as the 26 when worked over . I wonted the head to be ITB and not hydrolic tappets for a start ,the down side to the 26 head is the chamber size ,so its not the best option for a high comp race engine ,but the head i have was off a real race car that was raced by team i worked for in the 90s . So it had all the right stuff and had been ported by the best men in the world at the time so i had to use it , the chambers are still big at 58cc but with the 3.4 stroke and bore ,and with a big bump in the piston it will be ok Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 23, 2012 Share Posted January 23, 2012 I would say I'd like to see it run and it's results, yes! NASCAR is a limited engine class true, unlike Bonneville where as long as the head studs aren't moved you can pretty much do what you want based on the stock head. I'm sure V8 Supercars is similarly restricted in many aspects. None of the L-Heads I've seen by anyone are close to the FIA L-Heads cast by Nissan in limited numbers. And let's recall the old 1983 Road & Track article quoting E-motive at 750HP @ 7500 and 21.6 psi boost... Which was accurate, but did not reveal the true capability of the engine of 1100HP @ 9000 and 30+ psi boost. The L-Engine is not to be underestimated. Especially as somehow limited as a two valve non-crossflow head. Ultimately, the PMCS/Nissan teams ceased development on the S20 around 345HP from 1998cc's back in 1971~2 At the time it was pursued because it was thought the L24 was not capable of reliable operation at 9KRPMs... They only had slightly lower output, but were more drivable. Quote Link to comment Share on other sites More sharing options...
PMC raceengines Posted January 23, 2012 Author Share Posted January 23, 2012 Yes in turbo form they are a very good engine .The down side i had was trying to get inlet temps down in a race as i went up in hp and boost. When it made 600 hp atw it was a monster but it would start to drop off as the motec removed timing as the heat got into the inlet manifold . and i went thru 4 blocks as i tryed to push over 500hp atw with cracks in the bores , so i just stoped and went to the NA with ITB 48 mm and 13.1 comp L29 this made 193kw atw and was a fast car Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 23, 2012 Share Posted January 23, 2012 Electromotive had some good solutions to the very problems you mentioned, some of which has been discussed on this very site. We're not as much a bunch of shade tree mechanics as you might think. Temps will ALWAYS be an issue at 300hp per liter, but teams like electromotive proved it could be done on the L motor. I think we're actually in a much better situation today as 1. we're not bound to some of the limitations they had in their rulebook, and 2. EMS and turbo systems have vastly improved since then regarding what the consumer level person can get a hold of. I admire the determination on getting that RB26 head to work, and can't wait to see it in action. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 23, 2012 Share Posted January 23, 2012 E-Motive principals are quick to point out they never had a DNF due to cooling issues! Quote Link to comment Share on other sites More sharing options...
josh817 Posted January 23, 2012 Share Posted January 23, 2012 (edited) This thread needs more pictures and annotations; he's mucked up the water a bit with the twin cam head that doesn't need to be chopped into thirds. I'm curious about the oiling system and the oil return thing you mentioned. Edited January 23, 2012 by josh817 Quote Link to comment Share on other sites More sharing options...
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