No one?Originally Posted by Miniliteman
No one?
It did not produced a lot more power (+/- 20 Bhp more from same head) but when I stroked the engine to 85mm (+ overbore 93mm) the torque was a lot higher, made it "feel" like a lot more power. Some have build 2600 cc from a new alloy block. Must be a great engine.
I'm waiting for the first real down draught head to be tested on my dyno. Mark has promised me one. Maybe this is the way to make real power ?
Last edited by Dyno; 07-05-2015 at 22:25.
Thing on my mind was keeping the reciproking (spelling?) maas to a minimum so all the stuff that goes up and down.
With a NA engine to make big bhp you need high rpm so keep the weight of the conrods, pistons, valves, valvesprings low.
I don't think this will matter much. At least, it's not going to show much extra power on your dyno needle. OK, all little things do help but Pinto's, being 8V don't have much cylinder filling past 7000 RPM. So well within the limitations of valves, pistons, conrods etc.. A good one will never rev higher as 8000 RPM (and still making power). Max power is more often 7000 to 7500 max. You can of course rev higher but the power will not raise. As long as you can't make the head flowing more air, no extra power when running higher RPM's. And very fast cams just don't help. With faster cams you will first loose low RPM torque and power will only go up little in higher RPM and come to a point installing a faster cam means a drop in power all the way. Only and only if you can make a head that can flow more air, the extra duration will have sense. And this is about the point most Pinto's get stuck. Usually just under 200 Bhp if you want "rally torque". You are nothing with and engine making 200 Bhp and power band way to narrow.
PS: David Vizard did made a 200 Bhp+ Pinto in his book but if I look at the power graph and compare what I think is needed for a good rally engine, this engine was sh*t.
Last edited by Dyno; 08-05-2015 at 22:52.
Dirk,
if you have a head that flows extremely well then it will make big bhp on top-end rpm as long as the 'losses' are minimal.
That's why the DTM and F1 engines have one-off pistons and conrods.
If you have a heavy flywheel then accelerating the engine fast is compromised as you have alot of mass to accelerate.
Also when you want high rpm (NA means high rpm if you want big bhp) then keeping the reciproking mass to a minimum is a must.
The rallyteam I used to work with (a bit) had a Pinto with a trick head, one off extra lightweight pistons, rods and valves.
That meant you can use single valve springs also!
Engine made 218-220 bhp flywheel bhp and ran to 8800 rpm easily.
Same method was used by the engine builder for the BDG; that made over 280 bhp and ran to 10000 rpm with ease.
Leon.
I understand, if you run higher RPM's , rotating and oscillating mass (specially the last one) does taken energy. But in case of a Pinto, not running 12000 RPM or higher, I don't think the difference can be measured in more than 1 or 2 Bhp. Indeed, light valve train and soft valves are a real advance. About the flywheel and rotating mass, this is a compromise. The acceleration "in gear" will not vary so much anymore once you are in 3 gear or higher (mass of the car becomes a much bigger flywheel). And in lower gears, lower RPM's you will need some rotating mass or you loose power.
All my engines already have steel (light) rods and forged (light) pistons.
My friend had a turbo engine for autocross, big tuned, light flywheel. Compared to the big increase in power, there was little increase in extra speed. Until he started increasing the weight of the flywheel. For autocross, 4x4 buggy, he ended with 18 kg flywheel for is 450 Bhp 4 cylinder turbo engine. And this was a car competing in European Autocross.
Hi how much hp will an rl31 cam in a. 2 litre pinto make at the rear wheels on a dyno dynamic dyno with twin 45mm carby and 38mm chokes with 10:5:1 compression with a goog group1 head cheers mario
Totally agree, mine engine will rev to 7500+ but there's very little point in revving past 7200, in fact I have my limiter set to 7300.
Correct, in a rally-cross engine I set rev limiters at the "limit" of the engine so they can go up in RPM when they need it. But for rally or endurance racing, I set a lot lower.
I'm waiting for the first DD head to be tested. Hope by the end of this Summer so we can run it at the Semois rally. This might be the solution to make the engine rev higher WITH power.
The last one I've tested with Vulcan head, little over 190 bhp. But if the head is less sophisticated, power can be as low as 165 Bhp for the same camshaft.
That's flywheel horsepower.
Power at the wheels depends on transmission and tyres used but say 160 - 165 @ wheels.
Yes, Flywheel power. I don't talk about wheel power nor do I believe all the calculations they try. Don't want to open this case anymore.
I've done a test with my dyno. Measured an engine in direct (drive 4th gear). Then I took a dyno run in 3th gear. It does not drop exact over the whole line. The drop at lower RPM is a lot bigger. But rolling road down coast data is just opposite. The lost is one line from high to low RPM. But the real gear lost, and I do not have a final drive, will be worse. Seems to be opposite and also not a straight line. And vary from engine to engine.
Who the f*ck can calculate wheel lost correct if the gear lost is always different and for sure not a straight line. In newer dyno's they just put a lot of data found out of test work into the program but none is right. OK, if you want to compare, I'm gaining power or not, it will be OK.
190hp with 38mm chokes and an RL31? from a 2.0L????
155-175 @ the crank depending on head
Yes, 190 Bhp. I had little over 193 Bhp with HT1e but difficult to drive at low RPM low light (you can't measure, you have to feel). I've changed for A8 Piper and was better. Had the head fitted to a 2,3 ltr but went broke after 5 minutes because customer made an error in the dry-sump piping. Fitted the head back on a 2 ltr short block (not the same as previous but same build up). Now the head had little less CR because I took out some metal to lower CR in the 2,3 ltr from. I had a cam Piper A8 ready but the same week I took out a RL31 from a street engine to replace with ERSON 134. So the RL31 was in and I thought, let see what it does in a real cylinder head. I was more than surprised the power was so good. I try to add the power graph from both engines in next replay.
Same cam, first in 2 ltr with "ported" (??) big valve head and 2x 44 IDF (not an advance) and same cam a few day's later in a 2 ltr with Vulcan head. Same dyno.
Please note, my dyno does put a wrong date on the graph due to a computer error. Test where done approx +/-8 months ago.
I notice the same results in beetle and other engines. Power does not come from the camshaft. A good head is the way to make power. Beetle engines with W110 and standard head make +/- 85 Bhp average. Same engine, same original valve size but CNC ported by a German company, power raise to 115 - 117 Bhp. Every time and I still dyno test a lot of these engines. So not just one to compare but at least 50. We are now using a much "slower" cam and still got the same numbers.
Note 36 mm chokes. 38 made no extra power.
Last edited by Dyno; 15-06-2015 at 08:22.
years ago i had a 2.0 bmw engine just nudging 200bhp on a pretty racy 316 degree cam, i then tried the next cam up a 336 degree monster, which was supposed t give a LOT more power, it didnt, a couple of horsepower and that was it, yes reved on better, and even had a slightly wider power band, all be it higher up the rev range so was actually harder to keep on cam. that same racy cam worked well in a big cc motor, but in a 2.0 clearly it was too much, for the head spec at any rate
I notice the same results in beetle and other engines. Power does not come from the camshaft. A good head is the way to make power.
That's correct Graham, the bigger the engine, the more cam duration and lift it can stand. I've build quite a lot S2000 Honda engines. The low cam is OK up to +/- 6500 RPM. It's just no advance to switch to the high cam earlier, will not make more power. I recently tested a long stroke version, 2,4 ltr. I had to switch the cam's from as low as 3000 RPM. I could not because the oil pressure was still to low so I had to dial in 3500 as starting point. You can already see a small dip in the torque curve because the power on the low cam was already dropping of. 3500 RPM earlier !!!!
This engine would be better of with slightly faster primary and secondary lobes.
what the max compression to use with cam rl31 with 98 octane fuel and what igition timing cheers mario.
I always focus somewhere between 11 and 11,5/1. I never see power raising anymore beyond this point. I've you use 11,5/1 it can't go wrong.
Depends on Pistons? cast are limited to around 10.5 .1
Dirk,
regarding the graph and the numbers on it:
did the IDF's only have 32mm chokes?
And I personally do not like the 'correction factor' applied to the actual measurements.
When you do not correct the measured power the 145 bhp becomes 139 bhp and the 189 becomes 180 bhp.
Leon.
Yes, 32 mm, this means, I did not received more power with bigger chokes.
I don't understand what you mean with "don't like correction factor". This is the correction factor any dyno software will add to the actual measured power. If not, and tomorrow it is hot, barometer moved or humidity changed you can no longer compare. Even during the day it can vary a lot. The system automatic calculate DIN power. It recalculate to sea level, 50% humidity and 25° (if I remember but can be 20° also).
Again, do not know about ANY dyno who does not recalculate these numbers. This is for sure NOT cheating. Only in the winter, when very cold I sometimes receive opposite numbers. At -10° outside the air in the test cell can go lower as 10°. Humidity not seldom round 30%. Measure the same engine that day and "observed" power will be higher as what you finally get on paper.
Didn't say you was cheating but on some dyno's I've seen the correction factor was 20% or so.
My point is the correction factor is a theoretical compensation, just state what bhp was recorded with what temp etc.
Yes, 20%, that's cheating. Something I'm telling people every day. Unfortunately, if you want to compare your mods tomorrow with the one tested today you need to "correct" to the same standard. No way out.
I've seen turbo dyno graphs with hugh compensations. This is the case when people put the dyno recording temperature sensor in the inlet manifold of the turbo engine. Air is passing at high temp en the dyno recalculate the power back to 25°. This will add a lot extra power to the graph. I call it cheating. The temp sensor has to be at the entry of the turbo. If they still want to log intake temperature they need a second temp sensor. Not one that makes calculations.
If it can help, I can still ask the dyno program to show me the temp, humidity and barometer it was using that day. It's all logged data.
hi onyd what igition timing will i need to run with 10.5.1 compression like 32 0r 34 degrees all out at 3500rpm.
Why not fill the inlet port with liquid metal then CNC it ?
46 mm valves ? Where from Jason
I had a port developed using filler and got quite good results. I used standard size tulip valves for the development work. Next I placed the valve in the lathe and copied the grp1 wasted stem design onto the standard valve. It was unexpected but the port did not work well with this flat backed wasted stem valve.
Can you please share the photo of your tulip shape valve ?
What flow bench are you using ?
Interesting idea.
What liquor metal material would have good adhesion to cast iron ?
But, of course, there will be limitations on the port roof when re-machining/re-creating the new port.
no suprises there! the standard port arrangement shoots the mixture straight across the back of the valve so a penny on a stick design works best, but once you start to downdraft the port and the air flows directly at the back of the valve the penny on a stick is about as aerodynamic as a barn
I see Jason has not added to his thread since post #35. Could the bickering perhaps have caused his absence?
Jason - if you have more info to share I would love to hear it. Maybe the arguing could be taken outside?
1970 Mk1 Escort Tarmac Rally Car
Unfortunately Jason hasn't been around on here much at all.
Just looked at his profile and last visit was November last year.
Shame really,
jason comes and goes...............
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