how much rpm can i take?

[vintagewagenwerks]

The ever returning question in my mind ,since 2 year my bug has a 2017cc engine,on the dyno it pulls 164hp at 7120rpm,but when i heard the screaming of the engine during the dynopull my heart was pounding on high rpm too.
So how much rpm can such an engine drive on the highway without getting damaged,i bought the engine with less then 10000km from new out of a customers car and tuned it up a little bit.

Here are some specs.:

42/37 valves on 044 heads

78,4 öttinger crankshaft

1.25 rockers

48 Weber IDF carburators with 40mm venturis

42mm merged header

26mm oil pump with csp full flow oil cooling adaptor ang pressure regulatin rod

AS41 case

90.5 mahle pistons and cylinders

1.5 l add on oil sump

cam is unknown


When i drive the engine a little bit rough ,i shift up at 4500 rpm and on the highway 4200 at the time with 85 degrees oiltemperatur.My problem is in my head ever thinking of my blown 1678cc engine the cracks at 7000rpm on the highway in the past ,while i hear the big noise from the back of the car,this is my second big engine so my experience with that is not quiet as good.

If someone can give me so advises ,i would be very happy.

Thanks martin

[Type1/DVK]

it cán do 7120rpm, so keep it under that. Best would be (also for you're own bloodpressure ) to keep it under/around 7000.

[vintagewagenwerks]

That is a very good advise .My blood pressure rises with the rpm´s,my opinion is to drive as a serial engine with 4200 on the highway ,but to know the lots of power can make this decision down to irrationality.but the fear of cracking these engine like the first will win ,that´s my luck ,when i see my friends running 5500 or more ,never got any damage in years and do dragracing and all that ,let me ask this question what my engine can take.
For normaly i am a cruiser that want to feel the power of the engine sometimes,i do not drive any drag races with this ,because the money that is spend to the engine is earned very hard.

[Harry/FDK]

85C degrees is perfect, go 6500 and use the rest for overtaking with the shiftlight on.

[bugnut68]

I've just built a similar engine with similar specs, only 45mm Dellortos and an Engle 125 cam... reading this post gets me stoked to get it in the car and drive it. 

[Torben Alstrup]

You left out some vital part of information. - Camshaft and valve springs.

But on a general note NO VW type 1 engine should cruise higher than 5000 rpm. Stock cranked engines 4500 rpm. The better the balance in the engine the higher rpm can be driven. But the above figures are what I advise my customers to live by.
T

[vintagewagenwerks]

the cam is unknownfor me because i didn´t open the case ,there are only the infos from the bill the first owner gave me ,there was lksted the öttinger crankshaft it was taken out of the tsv2000 engine he owned before in his original öttinger cabrio,the crankshaft,flywheel were counterweighted,i modified the heads witch manley valves and a little porting works,and installed 1.25 rockers and changed the carburators from 40 idf to 48 idf,installed also a 42mm merged header,this combo was driven on the dyno with up to 7500rpm with peek power at 7120rpm .

The only things to the cam characteristics is that it pulls fast to 5000 and goes a up 5000 more slower and slower to 7500 but it will take a few seconds.I only drive 4200 on a highway but not for long times and shift during a sprint at 4500 today i tried 5300 it also was no problem for the engine ,after shifting from second gear at 5300 to the third gear you can feel lots of torque an the engine got very powerful in acceleration.

[Type1/DVK]

so it's easlily capable of 7100-7500 so get it up to 6500 and enjoy your engine no problem. 4200rpm it then only beginning then!