New 2l Race Engine

[midnight motorsport 0]

I know for a fact that they pump up at 7500 under sustained RPM. A quick traffic light blap might be ok for more, but not down the main straight. 7400 is the Mi16x4 limit so I'll stick with that until I put the solid head on. What hydraulic grind will make power to 8000 anyway?

 

hi pete, ah see thats what i needed to here, lots of people say that 8000 is ok, the cams i have are kent pt1604, they are 316 duration, 10.84 lift, 52/84 84/52 timing, full lift 106, they are supposed to be the highest spec cams for hydralic lifters, power is supposed to be 3500-7500, but with that sort of duration i expected it to be higher? no other cam grinders seem to use that sort of duration with that lift, and use split cam timing, do you think they pump up due to the oil pressure, although the pressure relief should sort that out?or because they just dont have enough time to recover at that rpm? i am now thinking that i should avoid the stronger spring that i have, as this may cause them to pump up earlyer? now im really thinking!! also a friend has a 16v vauxhall running standard engine and throttle bodies and mbe, that thing revs to 8000 no problems? been going for a while too,

i suppose that i wont be sitting at 8000 all the time, maybe when it is needed. maybe ill keep 7500 limit 8000 for special occations!! lol

Edited April 4, 2007 by midnight motorsport

[Sandy 189]

I think you'll sacrifice alot of range, manners and certainly economy with that much duration and little lift.

[petert 550]

The inlet cam I'm using has only 9.2mm total lift, yet it has a very broad power range. It's quite big at 243 deg. duration @ 0.050" lift. You don't need to open the inlet valve a long way on an Mi16 because the port flows so well. I'm using my Stage I grind on the exhaust, which is 226 deg. @ 0.050".

 

The 1604 inlet is 244 deg. @ 1mm, so it's a fraction smaller than the one I'm using. I think you'll be fine so long as you use a smaller exhaust cam and have at least 11.5:1. Too much overlap will just waste fuel and kill the bottom end.

 

DrSarty, coil packs on an Mi16 make an appreciable difference, especially down low, off idle. Individual coils per cylinder certainly is the best, but even wasted spark is a huge improvement on a distrubutor. Yes, you could just swap the head to larger displacement iron block.

[midnight motorsport 0]

The inlet cam I'm using has only 9.2mm total lift, yet it has a very broad power range. It's quite big at 243 deg. duration @ 0.050" lift. You don't need to open the inlet valve a long way on an Mi16 because the port flows so well. I'm using my Stage I grind on the exhaust, which is 226 deg. @ 0.050".

 

The 1604 inlet is 244 deg. @ 1mm, so it's a fraction smaller than the one I'm using. I think you'll be fine so long as you use a smaller exhaust cam and have at least 11.5:1. Too much overlap will just waste fuel and kill the bottom end.

 

DrSarty, coil packs on an Mi16 make an appreciable difference, especially down low, off idle. Individual coils per cylinder certainly is the best, but even wasted spark is a huge improvement on a distrubutor. Yes, you could just swap the head to larger displacement iron block.

 

hi pete, thanks for the replys, ah, so you do all the measurements at 1mm lift, i totaly understand about the overlap, and loss of low down power, prob not going to help running webbers either!! me and the old man were thinking about different exhaust cam, but just dont have the time, 5 weeks till nurburgring, and engine still in bits along with carbs to be set up etc etc.... , and we were wondering about advancing the inlet slightly to get back some of the midrange ,but that will only increase overlap, or retard exhaust cam? but the exhuast will be opening so early, its going to harm the power i think? any ideas, to help these cams along, as i cant change the exhaust cam, , not really sure if its possible, cheers, jay

[petert 550]

I've got spare exhaust cams if you want to go that route. Another option is to use a std. inlet cam on the exhaust. To reduce the overlap you need to advance the exhaust cam.

[midnight motorsport 0]

I've got spare exhaust cams if you want to go that route. Another option is to use a std. inlet cam on the exhaust. To reduce the overlap you need to advance the exhaust cam.

how much of a difference is the inlet cam to the exhaust? yes you are correct advance the exhaust,not retard, sorry, trying to write fast and think!! but thats what i meant, do you think that the pt1604 ex cam is real no no?

[midnight motorsport 0]

I think you'll sacrifice alot of range, manners and certainly economy with that much duration and little lift.

 

hi not to worried about range or economy, is not going to be a daily driver, but it does need to make it all the way to the nurburgring without a bank loan!! lol

[Sandy 189]

By range I mean range of usable revs, making for a narrow on/off power band.

[DrSarty 90 1 Cars]

By range I mean range of usable revs, making for a narrow on/off power band.

 

This is where my mind is taking me with regards to 'ways to define the useable/tractable power of an engine'. Not trying to change topic but one must assume that engine designers - and I include Sandy/PeterT etc - must have an application in mind, such as tracks, hill climbs, auto cross, sprints and rallies and to that end, locate deliberately the delivery of power within the band of the complete rev range that's going to prove most beneficial.

 

I'm not trying to uncover a revelation here (well I have recently experienced several moments of clarity ), but what I mean is, one may create a 240BHP Mi16 engine, but it's all happening at 6000rpm AND (my point really) this is a peak delivery and the components used means output is relatively poor either side of this.

 

So this ficticious engine's 'Sarty Power ' figure might mean from a full rev range of 7200rpm, if it delivers its top 15% of torque/BHP i.e. >204BHP over a narrow 500rpm, which is 7% of the total rev range (all random figures but hopefully you catch my drift), then it could have an SP index of 204/7.

 

Maybe slightly off topic I know, but there are some clever geysers in this thread whose opinions on the usefulness/uselessness of BHP as a fair representation of an engine's tractable capabilities. Is the SP Index a fairer system?

 

Thanks for the answers on my suggested engine Pete and I'd like to show my appreciation for really detailed topics such as this. Good luck at the ring Mr Midnight and Sandy.....I'm not worthy

Edited April 6, 2007 by DrSarty

[Sandy 189]

IMO, for crossover cars that see regular road use etc, such as most of the cars on this forum; engine usability, economy, manners are all important issues. Alot of people think it's acceptable to have a grumpy, thirsty engine with power that's difficult to access; because that's what tuned engines are like. Highly tuned engines are often unavoidably like that; but trading a little peak power and choosing well matched components, well set up, can be alot better than you might expect.

 

(Sorry to stray a bit)

[petert 550]

how much of a difference is the inlet cam to the exhaust? yes you are correct advance the exhaust,not retard, sorry, trying to write fast and think!! but thats what i meant, do you think that the pt1604 ex cam is real no no?

 

Sorry, I was thinking too fast as well! The inlet and exhaust cams are identical. I'd use a std. exhaust cam before I'd use a pt1604 exhaust cam. You'll get a much nicer engine with a broader power range.

 

DrSarty, you're correct in trying to get a broader range. My engine has 90% of it's torque available from 4000 right through to the 7400 redline, peaking at 6000. It's a nice flat torque curve, but up where I want it.

[petert 550]

I've finally got around to getting a copy of the power run. Sadly the printer clipped the best part! Anyway, 83 km/h = 4000 approx., 149 = 7100 approx. Note the nice fat torque curve.

Edited April 16, 2007 by petert

[petert 550]

The car had its first run yesterday, and other than a dead fuel pump, the car performed flawlessly. I hadn't driven for two years, so it took a little while to get onto the groove. It's definitely a better car than I am a driver! As expected with so much torque, I had to be carefull not to light the tyres up exiting corners. Gearing was spot on for the circuit (4.4 diff, 1.9 gears), pulling 7000 in 5th half way down the main straight. Hopefully will have an in-car video soon. Now its well and truely bedded in, I'll give it a final tune up on the dyno next week.

 

It was also good to catch up with Sam, who made his way out to the track from Manly via public transport (a difficult task!)

Edited May 13, 2007 by petert

[Sam 4]

Thanks Pete, was a brilliant day, better than the same old stuff I do here. Your car looked great and seemed to be performing well, there's always something to break on a pug... Sounded lovely too!

 

PS. Sorry about the seatbelt thing! I was half asleep, infact I fell asleep on the train!

 

See you at the next one (August you say?). I'll try and get some bits sorted (sump spacer & oil pump pickup) as I was wondering if you could do your magic on them?

 

Thanks again, nice to meet you!

[petert 550]

Here's a video of the first outing at Eastern Creek. The camera is in my car. I'm following Parry in his 1.9L 8V.

Edited May 17, 2007 by petert

[smckeown 1]

Some good footage there Pete. I seriously recommend you give your screen a good clean next time

 

You can see the power difference in that straight, but all hail the better handling 8v only less than a second a lap slower

 

2 P Taylor - Peugeot 205GTi(16v) - 1:55.5200

3 Perry Anastakis - Peugeot Gti (8v) - 1:56.6000

 

Taken from http://www.natsoft.com.au/cgi-bin/results....05/2007.EAST.S1

Edited May 17, 2007 by smckeown

[pug_ham 240 3 Cars]

Nice sounding angry snarl from the intake nosie peter.

 

Have you got a picture of the circuit layout?

 

Graham.

[petert 550]

The car that came first was my old car, another 205Mi16. Oh well. Here's a layout of the track, along with maps:

http://www.eastern-creek-raceway.com/

 

I'll post another video later from earlier in the day, where the screen is clean. There's a tube from header tank overflow sitting under the LH wiper. You'll notice it spraying out if you watch that corner.

[pug_ham 240 3 Cars]

Looks a good circuit, was it full circuit in your video or do they have shorter one's for different events?

I'll post another video later from earlier in the day, where the screen is clean. There's a tube from header tank overflow sitting under the LH wiper. You'll notice it spraying out if you watch that corner.

I noticed that towards the end of your video, I first noticed it when you passed the 8v & wondered if it was a sign of its demise but then I saw it again later on & figured it wasn't.

 

Looked like it was smoke or steam, obviously steam or water vapor.

 

Graham.

[petert 550]

That was the full track. There's no short track option at that track. Here's the benchmark for a 205:

http://www.natsoft.com.au/cgi-bin/results..../05/2004.ECR.SS

 

Adrian Wuillemin did a 1:52.6 in a 205Mi16.

 

Here's another clip from earlier in the day. I just love the sound. Shift point is 7200. The squeal is coming from the Brembo's with elcheapo Valeo pads.

 

[smckeown 1]

great vids, the track is rather fast flowing isn't it.

[DrSarty 90 1 Cars]

Engine sounds sweet, but the track being pretty twisty seemed to stop you really opening it up Pete.

 

God I miss my Mi

[kyepan 291]

what are you doing up at 5am in the uk?

[petert 550]

EC has the longest straight in NSW, other than Bathurst, so it's not that bad. Some complain it's not demanding enough for cars, but I've still got plenty to learn. Hopefully, the engine spends most of it's time between 5.5K and 7.2K

[pug_ham 240 3 Cars]

Just got to love the sound of TB's.

 

I was about to ask what the difference was between the two classes for the difference in lap times;

• 1 143 Parry Anastakis CLA 92 Peugeot 205 Gti 1900 N2A 19 19 2:00.1700
  
• 1 46 Adrian Wuillemin CLA 88 Peugeot 205 1905 N3A 15 15 1:52.6900
  
• 2 146 Owen Wuillemin CLA 88 Peugeot 205 1905 N3A 15 14 1:54.7300 0:02.0400
  

but you answered it already, the class N3A winner is an Mi16 not an 8v.

 

Track looks good fun, glad to see I'm not the only one that grabs the wrong gear now & again.

 

Graham.