1969 911T with E cams or S or Solex??

[kav]

I have a question about camshafts on my 1969 911T build. I was talking to someone the other day about my engine rebuild and they asked why I had gone with an E cam when I have the 81mm JE S piston is giving me 9.5:1 compression. Why did I not go with an S or Solex cam? My reply was I'm following the recommendations in Wayne's book. But could I have gone with S or Solex cam with the 81mm piston and stock 2.0L heads? Were all 1969 2.0L heads the same or did the S have bigger ports for the cam?

Trouble finding the specs online.

There is another post in the works for part 4 of my engine rebuild! (sorry I've been away and busy with work)

Cheers!

-Kav.

[horizontallyopp]

S had bigger ports and bigger valves, and cam to match. Drives the power up in the rev range.

I opted to have my E cams re-welded by Dougherty Racing to his DC30 grind (mod-Solex) which should be a good fit with the smaller 2.2 T/E ports and valves, compression bump, single plug and running carbs.

Now if I ever get the engine back together, I'll tell you how it works

[cmcfaul]

e cams just have to be cut, not welded to get them to DC30 specs. I started with this set up using e cams on a 2.4. Car ran nice with lots of torque but ran out of steam before redline. Had cams cut to DC 30 spec and holy ****, it pulls hard then hits a power a band at 6k to 7.2k RPM.s it wants to pull further into the redline but limiter wont let it (for good reason). 9.5 CR with DC30's is a GREAT, proven setup!!!

73 E

[kav]

Originally Posted by cmcfaul

e cams just have to be cut, not welded to get them to DC30 specs. I started with this set up using e cams on a 2.4. Car ran nice with lots of torque but ran out of steam before redline. Had cams cut to DC 30 spec and holy ****, it pulls hard then hits a power a band at 6k to 7.2k RPM.s it wants to pull further into the redline but limiter wont let it (for good reason). 9.5 CR with DC30's is a GREAT, proven setup!!!

73 E

Sounds fantastic! It's a little to late for that now but it could be something I look into in the future. I will give John Dougherty a call and talk to him about my setup and seek his advice.

So to re-cap with my setup:

E cam gives you good low end torque but may run out steam at the top end.
Solex cams will work with my heads and is a good option to give you more top end
S cams will require porting the heads or a set of S heads and have most of the power delivered in the upper rev range.
DC 30 cam profile from Dougherty Racing Cams works with my stock T heads, 9.5:1 compression, gives good power through the rev range and can be easily ground from E cam.

(where is my time machine??!)

Cheers.

-Kav.

[Trackrash]

The reason for running out of steam at higher RPM COULD be due to the smaller ports and valves.

My old SS2.5 T motor, based on a 2,2, with E cams would pull to over 7K RPM. The difference is the 2,2 has the larger valves AND I opened the ports to S size.

Yea, John is the man. He is a great resource.

Remember, the cam will largely determine the power range your motor operates in AND it needs to be matched to your intake and exhaust systems. Too much cam and you will have poor driveability.

FWIW, the DC30 sounds like you are on the right track.

[Gene Smith]

You cannot go wrong with Mr. Dougherty. He restored my 50 year old S camshafts and I'm very pleased. Before you expect miracles take a look at a real '69 911S head- Those valves are HUGE.

[cmcfaul]

Don't think any head work is needed regardless of cams. It will breath better with bigger valves sometimes at the expense of torque. E cams on a higher compression engine is a nice upgrade. A step further, going with the DC30's is fantastic!!! With the DC30's it will be on full HP at redline. If you can lighten the valve trane to take advantage of higher redline potential you will really have a hot engine.

[kav]

Just emailing Mr Dougherty and he says my T cams that were ground to E cams won't take the DC 30 grind? I would need original E cams?

[cmcfaul]

yes, you would need original e cams. T cams cant be ground into DC 30's (going by memory). Higher compression with e cams is not a bad setup (WAY better than stock T). just DC 30's take it to the next level and compliment the higher compression.

With any cam change, you will need to pay close attention to AFR. A lean mixture + high compression = detonation and eventually severe damage.

Chris

[kav]

Yes this just in from Mr Dougherty,

E on T will reduce the base circle. IF its just a grind and not a welded up cam. As a regrind its in the acceptable base circle diameter range. Grinding them again to the DC30 will make it too small. The original E cams start with a bigger diameter, so grinding them to the DC30 is ok, stays in that range.

[Emo993]

John just did my S grind cams to DC 30, also had the rockers rebushed and surfaced. John does a great job. My engine is a 2.2E with S pistons and PMO's, can't wait to have it running. Best, Mark