HI Everyone
Could some one tell me what the SAFE RPM redline is for a stock type 4 2Ltr Kombi, I have heard that the recomended limit is 4.5 thou, is this in
the ball park?
Thanks
:alien
It depends entirely on how long you want it to last. I Redline mine at 4500rpm, but it's happier not going over 4000rpm. If your top end is
breathing easier, it should handle 6000rpm as long as your bottom end is in good nick.
When it comes down to it though, the less you rev it, the longer it will last.
Oh yeah, if you want to rev it, get it all balanced. :thumb
[Edited on 21-2-2003 by KruizinKombi]
Thanks for the reply
As the Kombi is our daily driver at the moment,my wife drives it now as well, and she has a bad habit of, what I consider over reving it, so I
thought if I put a Tachograph in it, she can see when to up shift at the right RPM, and not be so cruel to the old girl.
My engine has done 260.000 Kms and has not had the heads off it yet, it is still going well and not using much oil on long trips, so I would like
to see how much I can get out of her before the inevitable rebuild!
Thanks..:thumb
In that case, keep it under 4000-4500rpm. You should find that it will chug along quite happily at quite low revs, just tell her not to be in a hurry - it's not a rice-burner.:thumb
I have heard you can get rev limiting rotors for them. Might be something to look for.
Not that my 2L is in the best of condition or tune, but as a stock dual carb. there seems little point in reving over ~3600rpm as there ain't
much to be gained.
On the other hand, don't let her load it up ! e.g. flat to the boards in fourth at 1200 Rpm up a hill, this will kill it quicker.
Does a Kombi have the gear selection marks on the speedo like a beetle ??
This would be the easiest way to control your engine revs, tell her to change gears on the mark.:thumb
Thanks for all the advice, I have a friend that has a few bits locked away, I rang him and he is giving me a rev limiting rotor button, I almost
choked when he told me how much they are new, over $50.00. I will put a tacho in it and explain to her the change points, now she has found out the
conveniance of the Kombi, I cant get her out of it!
Rob.....
Methinks that a stock kombi crank will rev to 7000rpm all day long for eternity without breaking. But it does flex and it flogs out centre main
bearing, so keep it generally below 4500.
I know there are some crazy people out there but I think its really obvious when you're over revving a type 4. They sound harsh and stop
pulling.
Personally I think, and I hope im not insulting people, if you need a tacho to drive around day to day then perhaps you shouldnt be driving at all.
When its loud... time to change gear.
They're nearly ALWAYS loud!!! :P
define loud:o
(not insulted)
Well there's yelling out loud, and theres yelling out loud that hurts your throat. The one that hurts your throat is bad.
:bounce
ok, so, if I got a phone call from my wife to tell me the engine had seriously ceased function & I asked her if she was holding the gears until it
was too loud she would yell at me really really loud,
WHEREAS if I asked her what revs she was doing when it banged, she would probably just say she wasn't looking and only yell a bit loud
A stock VW 1970cc Type 4 engine (CJ engine number) produces maximum torque of 103.7 ft lbs at 2800 rpm, and its maximum 70 bhp at 4200 rpm. There is
nothing to be gained by revving it any more than that.
Like a Beetle's, the Type 4 crank is not counterweighted so it will try to flex if you rev it too hard. A Type 4 case is not soft magnesium alloy
like a Type 1, but much tougher aluminium. It will resist the pounding out that destroys so many Beetle crankcases - but only up to a point, of
course.
A 70mm VDO rpm gauge fits beautifully in a Kombi dash, just to the right of the speedo. I bet yours has a blank plate there. They are super simple to
wire up - power, earth, lights and a lead to the coil at the back. VDO rpm gauges also have a rotating 'red line' hand that you can set
where you like.
My auto shifts gears at about 3200 rpm if I go gently, or about 3800 rpm if I give it a bootful. Holding and shifting manually at higher rpm gives no
improvement whatever.
Take your wife for a drive. and get her to listen to the engine while you go through the gears. It's easy to learn how the motor sounds when
it's ready for the next gear, both at the top and bottom of the range. I would reckon lugging would do more damage than over-revving.
Quote: |
its for a clock. not too many of those around either.
I dont realy like the VDO tach in there because its sits flush, although I did have one there in the old kombi. Now I use it for the boost gauge.
Maybe there are cheap tachos that are smaller. Wouldnt need to be accurate. Otherwise looks like this.
I think I will go with 4200, I want to get some more miles out of my engine, and if it dose not produce any more power after this, I spose it is just
wasting gas, not to mention over reving it, I have scored a rev limiting rotor, so that should give it some insurance! I have driven it for more than
15 years, and have had no problems, but now my wife has got her hands on it, I am a little worried, I just want to make it as easy as possible for
her, a visual aid (tacho) is a lot better than me getting frustrated and yelling at her, we have been together for 20 years, and I would like to at
least make it another 20.
I don't quite know where I will put it yet, I am one of the lucky or unlucky ones that has a factory clock! it is a bit noisey but it keeps
better time than my $500 seiko watch, I may just put it in a pod on the dash!
Thanks Rob :thumb
yes have one of those rev limit rotors for the wifes car,
now just have to get her to understand that "when its cold you dont have to
reach the rev limit ! "
maybe a new wife ??
just a thought !
Update - actually, just pootling around in traffic tonight, my auto shifts as low as 2100 rpm if I drive in a really relaxed,
I'm-Just-Cruising-Along way. Type 4 Kombi engines are so beautifully designed, so perfect for their application, that you just don't NEED
big RPM in normal driving.
Cruise along at 80km/h in top gear and listen to the noise it makes. It's turning over at about 2600 rpm at that speed. Speed up to 100 km/h and
it will be doing about 3200 rpm. Hear how it sings, remember what that speed sounds like. When you shift gears, do it when it reaches that point and
you won't have any trouble.
Gee Robo, that's a real 'pity' to hear about the clock being in the way. Wanna sell it?
Nah I think I will just leave it where it is, I don't like wearing a watch much, and like I said it keeps good time, I didn' t know they
were thin on the ground! I have had the van for quite some time now, i bought it off the original owner, they bought it from clough's in
Bankstown traveled around in it for a while, then the husband passed away, the widow decided to sell it, I was lucky enough to buy it, it was still
like new!
Rob........
Have to agree that the limit for a stocker is 4500, but there's usually no point going over about 4200 (except overtaking.)
But I thought I should point out that a rev-limiting rotor is not a good solution to habitual over-revving: The rotor cuts the spark out, which
leaves unburnt fuel running through the engine, which can wash oil from the cylinder walls and even in extreme cases dilute sump oil - please try to
teach your missus how she can drive faster by upshifting. While most people will quote 4500rpm as the rev limit, your engine can safely rev to
5000rpm+ , with less damage than a rev-limiter might cause...
Thanks guys
I looked in the workshop manual I have for my Kombi and it documents for my engine that it produces peak power at 4200, so that is what I will set
the red mark at, it is no use reving it to 4500 if it is not producing any extra power, it is just using more fuel,.
My wife can argue with me, but a tacho dosent lie, and now she has read the manual she nows it is correct!
Thanks
Rob......
[Edited on 26-2-2003 by Robo]
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the tacho with the light looks like a good idea!
I put a 0-4000rpm tacho in my Kombi. So the revs run out when the gauge does.
This way I get to run right to the end of the gauge, and don't waist any of it.