2.4 S Engine build

[MikeS911]

Hi All
I have just stripped a 2.4S Engine for a friend and have a question for the engine guys.

On inspection I found a mixed pair of camshafts. The Left Hand cam is the correct part number 901.105 183.0R but the Right Hand cam is part number 901.105.110.1R. this appears to be a Solex Cam? The engine has not been run for about10 years, but was supposed to run OK?

The correct can would be 901.105.168.00 and the timing specs are Intake Opens 38* BTDC and Closes 50* ABDC Exhaust 40* BBDC and Closes 20* ATDC, set to 5.0 to 5.4mm lift at Intake Valve Overlap, while the 901.105.110 timing specs are Intake Opens 29* BTDC and Closes 39* ABDC Exhaust Opens 39*BBDC and Closes19*ATDC set with a 3.0 to 3.3mm lift at IVO. The total lift for both cams are not miles out but are not exactly the same, as per timing.

Has anyone ever seen this combination before?

I have put is a Parts Wanted add for the correct part number and hope someone can help with a good usable correct part. In the meantime any comments. The Engine was from the US.

Thanks MikeS

[Lightweight_911]

.

901.105 183.0R & 901.105.110.1R are the casting numbers - there should something stamped (eg 'S') into the surface of the nose of the cam.

I've seen '110.1R' castings used in 'S' engines before...

.

[MikeS911]

Hi.
Thanks for the response, yes the numbers are the casting but I have never seen this combination before. Usually I have seen evidence of a regrind but these look perfectly original
I will go and check for other numbers stamped in,
Thanks again Mike

[MikeS911]

Hi Andy
Have just checked the cam has an S stamped in the nose, so do you think it ok to use this combination?
Have you ever checked the timing with a timing disc on the cam once set at the overlap? or do you just use the overlap setting. In the past I have just used the overlap.
Again thanks Mike

[Lightweight_911]

Hi Andy
Have just checked the cam has an S stamped in the nose, so do you think it ok to use this combination?

The only absolute way to determine what that '110.1R' cam is would be to get its profiles checked by a cam specialist ... but I've certainly seen/heard this casting being used in several other S engines.

Have you ever checked the timing with a timing disc on the cam once set at the overlap? or do you just use the overlap setting. In the past I have just used the overlap.

It's ~ 10+ yrs since I last rebuilt a 911 engine but I'm fairly sure I just used the std method of setting the valve lift at the overlap position ...

.

[MikeS911]

Hi Andy.
Thanks for the help. Mike

[911hillclimber]

Not sure if this will help:
I've done 4 911 rebuilds, a 2.4 and 3 x 3.2's.
Have only used the valve lift method as it has been the only method described in several books on rebuilding these early air cooled engines.

The excellent Dempsey engine re-build book is a god-send of info, and on page 207 all the cams are detailed.

You would need some special measuring instruments to verify the specifications, but when i build my high performance 3.2 a few years ago my new G60 cams came from Kent Cams who may run your cams through and verify the spec.
They were great to deal with. Call: 01303 248666

Brand new 4 bearing cams cost £760 the pair to the G60 custom grind, delivery was 48 hours!

Another avenue would be the Head Shop up in Warrington who do a lot of Porsche rebuilds on these classic engines, they did the twin plug mods on my last 3.2 and again good to deal with, quoted a price and delivery and stuck to them to the pound and the day. I think they can check the cam specs too. Worth a call: 01925 851166/77

Possibly in the past the cams may have been re ground to another spec, so checking them is a good move.

If you don't have the Dempsey book invest in one. (I'm assuming you are 'new' to these engines).

[Mike911scrs]

Hi Mike
regarding your cams, the cams for a "S" should have a SE (01) stamped on the Nut end of the L/H cam and on the R/H a "S", if the cams have been re- ground, look at the base of the lobe and you will see it is close to the shaft, as in material has been removed, possibly on the other end of the shaft there may be a GRINDERS name/mark as to the state of the cam

1972-3 cams for ;

"S"engine Type; 911/53, 911/63 (sporto) L/H cam 901 105 183 01 (part No') with a marking SE(01), R/H cam 901 105 168 00 (part No') with a marking "S"

"E"engine Type; 911/52, 91162 (sporto) L/H cam 901 105 181 00 (part No') with a marking "NE", R/H cam 901 105 110 05 (part No') with a marking "05"

the markings are on the nut END OF THE CAM SHAFT , under the dot for TDC, or should be.

any more details on the engine? engine type No', injection or carb's

mist that bit; " The Engine was from the US." which say's it all

regards mike

[MikeS911]

Hi Mike

The cam I am questioning (trying to get a good replacement) has the wrong casting number as initially stated. I is stamped with an S on the nose and shows no sign of being reground. I am told the engine has been run on both carbs and an aftermarket injection setup. Once rebuilt it will be on EFI.

I aware that Porsche sometimes used available casting in the early years but had not seen this combination before, so was asking the question.

Thanks for the info

Regards Mike

[MikeS911]

Hi Graham.

Thanks for info re the Head Shop, I may give them a call and see if they can help, I have had cams from Kent Cams before but not for Porsche.

Again thanks Mike

[HaraldD]

Hello,
if you need really good cams, take a look:

https://frisiersalon-nowak.de/produkte/ ... orsche_911

The only problem is - they are from Germany..

Harald