Experience with Solex Center Lube Cams

[IAA1963]

Hi,

There is good progress on my 911 1964 project and I'll start to restore the engine now. Basically the engine should be restored to original condition. But I am not sure, if I should go with Solex central lube cams only. As I have learned they have increased wear due to low greasing while driving low RPM. That's why Porsche has changed to spraybar camhousings after approx 3000 engines.

So I am interested in some expirience of other street cars running with solex center lube. I want to drive my car, but as it is an early 1964 it should be good for show, too. Other solutions like central lube cams plus spraybar camhousings might be a technical improved solution, but not original for a 1964 ...

Any recommondations?

Mark

[304065]

Mark, use a larger oil pump like one from a 911SC, maybe have it modified for better flow, that should give you plenty of oil in the centerlube cams. Also do the oil bypass modification when the case is done, this will reduce foaming of the oil and give you better lubrication.

[Flieger]

This just gives you another excuse to keep the revs up!

[kenikh]

I love center lube cams - when I rebuilt my Solex motor, I kept that center lube cams and really like them. I agree that upgrading the oil pump, doing the oil bypass are the right mods. You can run center lubrication and spray bar lubrication concurrently, which is what the 935s did. The biggest challenge with rebuilding a center lube motor is the cam end seals. They are pretty hard to come by.

[IAA1963]

John, Kenik,

Thanks for your recommendation regarding oilpump and bypass. I know central lube cams and spraybar housings can be run concurrently, but this would be a visible change ... So I prefer the oilpump and bypass.

I was so lucky to score a new set of seals and cams :-)

Mark

[mhhm]

I love center lube cams - when I rebuilt my Solex motor, I kept that center lube cams and really like them. I agree that upgrading the oil pump, doing the oil bypass are the right mods. You can run center lubrication and spray bar lubrication concurrently, which is what the 935s did. The biggest challenge with rebuilding a center lube motor is the cam end seals. They are pretty hard to come by.

Having only recently bought an early (65) car with centre lube cams......"What & where " do I search for more info about the oil pump upgrade/bypass?
I would appreciate some direction rather than me doing a random "clueless " search.

Obviously this is a common upgrade?...May have already been done? Any way that I can check externally ( I expect not)

This stuff is all new to me...but Hey... I am learning fast!

Thanks
Bob

[304065]

Bob,

The oil bypass modification came in for the mid-76 model year, some cars had it, some didn't.




Basically the Factory figured out that having the oil pressure relief valve vent to the crankcase resulting in a high oil level in the case. The motion of the crank stirred this up, reducing horsepower (it makes a difference) and foamed the oil. They figured out that by drilling an extra hole to allow the overpressure to vent back into the oil inlet to the pump, and by plugging the outlet to the case, the oil level could be reduced.

The lower oil level in the case allowed the size of the scavenge pump to be reduced. By reducing the size of the scavenge pump, the pressure pump side could be made larger within the same physical dimensions of the pump. This allowed for better oiling.

The way you can tell is the external plug that covers the spring and piston-- period cars from the 70s have an annular groove around the screwdriver socket, and modern plugs have a hex head.

[mhhm]

304065, Thanks for the prompt reply and simple explanation..all makes sense.
I will keep this in mind for when we eventually take a closer look at the engine.

We intend to be long-term keepers of this car ( # 301606 ) and I doubt it will ever see a racetrack during our ownership..so long periods of sustained high revs are unlikely..but anything that improves its touring ability will be considered.

Obviously your experience/knowledge re; early cars is valued.
Would you object to the occasional PM??? ..as I develop my knowledge of them.

Thanks again
Bob

[304065]

Bob,

Keeping 301606 off the racetrack is rather like having Secretariat in the barn and keeping her below a canter. . one of the few places our cars show their true soul is at speed, under controlled conditions, with a shared set of expectations about driver behavior, in an environment of relative safety (compared to streets or public highways). Expressed another way, I've spent seven years restoring '065 and when she's finally ready I have absolutely no hesitation about taking her to the redline and 9/10 of the limit up at Lime Rock or Watkins Glen. (Which is a pretty low limit on 165/15 tires!)

The case modifications are not just for racing use-- they enhance the longevity of the engine under all conditions. When I did 065 I had the oil bypass mod, piston squirters, case clearanced for larger oil pump and all the rest of the tricks in Ollies' bag performed, under the theory that I'm only going to be in there once, so it makes sense to take care of all these things. Machine work was about $1,000 but it was done right by the experts.

I have left a trail of bread crumbs to follow: http://forums.pelicanparts.com/tags/901/05.html you can see how my thought process evolved from wanting to make performance improvements to the current enhancements within a pure concours package. . .

Happy to take your questions although the Forum gets more benefit if you ask them in the open so everyone can see the answers and chime in-- unlike most of the rest of the Internet, we have a policy of encouraging newcomers here and flaming is not tolerated.

Good luck and WELCOME.

[mhhm]

Keeping 301606 off the racetrack is rather like having Secretariat in the barn and keeping her below a canter. . one of the few places our cars show their true soul is at speed, under controlled conditions, with a shared set of expectations about driver behavior, in an environment of relative safety (compared to streets or public highways). Expressed another way, I've spent seven years restoring '065 and when she's finally ready I have absolutely no hesitation about taking her to the redline and 9/10 of the limit up at Lime Rock or Watkins Glen. (Which is a pretty low limit on 165/15 tires!)

Point taken, but I will need to build up to this.

The case modifications are not just for racing use-- they enhance the longevity of the engine under all conditions. When I did 065 I had the oil bypass mod, piston squirters, case clearanced for larger oil pump and all the rest of the tricks in Ollies' bag performed, under the theory that I'm only going to be in there once, so it makes sense to take care of all these things. Machine work was about $1,000 but it was done right by the experts.

Exactly why I pricked up my ears at the original post.

I have left a trail of bread crumbs to follow: http://forums.pelicanparts.com/tags/901/05.html you can see how my thought process evolved from wanting to make performance improvements to the current enhancements within a pure concours package. .

.

And very tasty crumbs they are, too! THANKS.

Happy to take your questions although the Forum gets more benefit if you ask them in the open so everyone can see the answers and chime in-- unlike most of the rest of the Internet, we have a policy of encouraging newcomers here and flaming is not tolerated.

Thanks and OK..I guess that's how I picked up this info in the first place. Sure is a wealth of knowledge here for a new owner.
My only previous experience has been through wrenching/driving of friends .... 356 ......and years ago ...a '68 ex-factory London to Sydney Marathon car.

Cheers
Bob