9000RPM!

[HairyScreech]

are the standard rockers steel or alu? never payed that much atention to them.

[appletree]

Do you realy need to rev that hgh with an FI motor though? wouldnt it be easyer to turn up the boost more and keep everything running slower?

I might be missing the point but do you realy get that much more power in FI buy revving that much more?

Can't you play about with turbo size to get more power lower? i can understand why if you've got a set up thats still pulling like a train at 6.5krpm then raising the rev limit that bit more.

[78dude]

I have an old School Alfa 33 with a flat 4 pot boxer engine and twin carbs and that can rew up to 8500 rpm

[HairyScreech]

look at it this way, if its on boost at 3000rpm then you have untill 6500rpm to get max power,
if its on boost at 3000rpm and you can go to 9000rpm then you have a much larger power band and any gain in power from the boost is multiplied by the revs the engine is doing.

also it might take untill 4500rpm to reach maximum boost so being able to hold that boost for so much longer will be helpful.

[Colonel Sanders]

they are cast ally i belive, my turbo wont hit full boost till 4000rpm, so if its only revving to 6800rpm, that dont really give much boost time, so need to rev higher but it needs to be able to breath well at high revs...

[HairyScreech]

lol, that what i just wrote at exactaly the same time as you.

also i supose it would allow you to have a higher compression engine so its still tractable with plenty of power when off boost but use the turbo to feed the air in as the engine looses it ability to breath naturaly, thereby raising the peak power over 5000prm without losing the tourque off boost that a low compresion engine can suffer badly from.

[Colonel Sanders]

yep, spot on, i have 8.0 cr, and a hefty holset turbo, wich will sit nicely at 1.2-1.5 bar, making between 400-500whp. 450 would be nice, and with not taking the cr down too much i dont loose much torque off boost,

[--alpina--]

Thanx guys, thats answered my question, all makes sence then, sorted!!!


j

[Onz]

yeah but BMW wont fit a Forged crank, mhale pistons, strengthened con rods and billet rockers or a high lift cam :p

[Demlotcrew]

look at it this way, if its on boost at 3000rpm then you have untill 6500rpm to get max power,
if its on boost at 3000rpm and you can go to 9000rpm then you have a much larger power band and any gain in power from the boost is multiplied by the revs the engine is doing.

also it might take untill 4500rpm to reach maximum boost so being able to hold that boost for so much longer will be helpful.

Only if engines would work like this

[Speedtouch]

The M30B35 apparently has a forged crank. I have revved mine to 7500+ a few times for short spells on occasions, probably not wise on a 20 year old engine but it is remarkable what these old straight sixes are capable of, being inherently well-balanced. The latest Nissan 350ZX made a big deal of the 7500rpm rev limit in their advertising!

[HairyScreech]

look at it this way, if its on boost at 3000rpm then you have untill 6500rpm to get max power,
if its on boost at 3000rpm and you can go to 9000rpm then you have a much larger power band and any gain in power from the boost is multiplied by the revs the engine is doing.

also it might take untill 4500rpm to reach maximum boost so being able to hold that boost for so much longer will be helpful.

Only if engines would work like this

true, a simplified concept but i didnt know how else to put it.

[rThor234]

This US spec Warsteiner car revs past 9k--




The M20 was built by a former F1 engine builder.

Didnt read through all of the posts, so sorry if I missed something.

[pacerpete]

never mind the revs, give me the cubes !

[Onz]

any more history on this ex f1 engine builder and development of the m20?

[rThor234]

any more history on this ex f1 engine builder and development of the m20?

No, unfortunately he left work ~3 weeks after I got hired.

I still have some contact info for the owner of the car, who knows the engine builder. I've been trying to get specs for a couple months now..

[Onz]

it looks like an awsome machine, would have been great to see it race!

[e21Jason]

Hi

Lots of m20's were buitl by ex f1 engineers (Back in the dfv days) becuase TWR ran a BMW's and a few single make e21 race series.

Fritz gets his heads doen by one of them and the other heads up BBR

Also you could buy 240hp 2.3m20 race motors of list from Hartge which ran to 8.5k


Jason

[Onz]

nice one Jason!

How much do you think those hartge lumps go for? And what have they done to them?

[e21Jason]

Hi well they only made them in the 70's for group 2 e21's. Due to the brand name if you could get one about 8k. Usaul kind of mods a but lot of head work on the e21 head and a kuggelfischer injection system.

Spend 8k on a m20 today you could get closer to 280hp
Jason

[Onz]

forget spending 8k on an M20, id rather buy an s2000 :p

[agreen]

forget spending 8k on an M20, id rather buy an s2000 :p

and stick the engine in a e30

WIN WIN SITUATION

[maxfield]

forget spending 8k on an M20, id rather buy an s2000 :p

and stick the engine in a e30

WIN WIN SITUATION

8k on an M20 will beat a S2000.

[agreen]

8k on an M20 will beat a S2000.

edit i am a ++++!!!

[maxfield]

Far from it dude!

M3. M5. GT3.

[agreen]

fair enough i am a goon lmao its late can i be excused

[maxfield]

It could be the most powerful 4 cylinder N/A engine in production today...

[agreen]

i hurd something like that on top gear ohh well should have jut said nothink lol

[Onz]

best handling drivers car in production today imho

and the best engine, not the most powerfull but about £200 in mods and you are flying past 300 bhp NA

[maxfield]

I don't agree on either of those if I'm honest.

[stonesie]

8k on an M20 will beat a S2000.

ok then max after all the s2000 and was i think the most powerfull n/a car in production was it not or am i wrong ???

If you mean BHP/Litre then the S2000 engine is 248/2 = 124.0

M3 321/3.2 = 100.31

M5 V10 507/5 = 101.4

on the Bhp/L figures the honda kicks ass and revs to 9.5K out of the box, not much bottom end though eaven with the VTEC


Those figures are all rough but give a good idea

[maxfield]

What about torque? Torque is much more important IMO.

And torque per litre?

[irish320i]

this is all a bit pointless with a single cam engine if your gonna rev that hard it will be either a total pig at low rpm or you ll sacrifice top end power fi is so much better at extracting power out of a single cam non vanos just my 2pc worth

[Onz]

fair play irish, but the real point of this thread was to figure out how to make the BMW M20 engines rev higher mainly for avoidance of "cracked head syndrome" these M20 heads are all prone to cracking and usually the oil spray bar doesnt oil the head properly or the cooling system doesnt cool it properly causing them to crack. I wanted to know if anyone has made modifications to avoid cracking heads. If you can rev an engine that high it usually means that i can handle the heat, friction and vibrations reached at those operating conditions. I have cracked a few heads in my time and its usually from over revving an engine with no gauges to tell me when to stop!

Any comments? how can we avoid cracked heads and still drive hard?

[Colonel Sanders]

weld the water channels. very common in fi.