x-faktory 2.8SS

al lkosmal · 08-25-2022, 01:21 PM

This is my friend Brooke's 2.8SS......swapping the carbs for 46mm PMO EFI, Dual dizzy, M'squirt and MSD........got it dialed in decently on the test stand. Ready for install into the 911....and then, let the tuning begin.....

regards,
al

Cairo94507 · Cairo94507's Garage

Sounds amazing!

digitaldgp · digitaldgp's Garage

That sounds Great!! Al

snbush67 · snbush67's Garage

Does it fire up nicely on a cold start? That motor sounds smooth.

al lkosmal · 08-25-2022, 06:06 PM

Quote:

Originally Posted by snbush67

Does it fire up like that on a cold start?

I think that you are likely asking a question you know the answer to....No, that was a warm start, after tuning for a while. However, it just needs a bit of pedal, when completely cold. I have the cold start settings, Warm-up-Enrichments etc. set pretty well now and it just needs a little pedal to fire up. The 911 this is going into has a hand throttle, so it will be nice. I much prefer the simplicity of the early hand throttle to the addition of an IAC valve.....nice blend of old and new.

regards,
al

Showdown · Showdown's Garage

There’s definitely a sweet spot in blending the old and new. But hot damn that engine does sound really nice. Now stuff it into that bug, Al!!!

jpnovak · 08-25-2022, 06:15 PM

early 3.0 turbo case? 95x66? Full oil mods for 9K rpm? what cams?

Yes, I have wanted to build one of these for a long time. I was thinking that 98x66 (2.0SS) would be pretty spectacular.

Engine sounds great. makes me want to revisit my AE settings.

snbush67 · snbush67's Garage

Yep, You caught me before I could edit with what I meant to say.

rswannabe · 08:27 AM

Quote:

Originally Posted by jpnovak

early 3.0 turbo case? 95x66? Full oil mods for 9K rpm? what cams?

Yes, I have wanted to build one of these for a long time. I was thinking that 98x66 (2.0SS) would be pretty spectacular.

Engine sounds great. makes me want to revisit my AE settings.

JP - yes, early turbo case, 66mm crank, Pauter rods, 95mm p’s & c’s, twin plugged 3.2 carrera heads, GHL 1 5/8 headers with heat into early sport muffler. I used to run RSR sprint cams, but couldn’t tune the 46 pmo carbs to be streetable and still make good use of all 8k rpm. I swapped in DC62’s for better streetability and dropped the redline to 7,500. With efi I can likely better tune across the rpm and I might go back to 8k cams, but one variable at a time.

al lkosmal · 08-26-2022, 08:03 AM

The Bug is in to get EFI'd too...........but not with the 2.8SS

Dpmulvan · 08-26-2022, 08:43 AM

Al You get the prize for shortest YouTube videos. Your one of the few on YouTube who I wish made longer videos with more commentary.

jpnovak · 08-26-2022, 10:32 AM

Brooke, Sounds like a very fun build.

rswannabe · 08-26-2022, 12:22 PM

Quote:

Originally Posted by jpnovak

Brooke, Sounds like a very fun build.

It’s a great motor. Originally it was built as a GT3 race motor by Rick Deman. I ran it for years in my ‘69 before replacing it with a monster 3.8. I eventually came to the conclusion I liked driving the car more with the 2.8 than the 3.8 (more fun and engaging) so it’s going back into the car now.

Jeff Higgins · 08-26-2022, 08:11 PM

Yes, this is an awesome motor, and it is going into an even more awesome car. I have fond memories from when Brooke let me drive this combination in its original guise, with the big PMO's and RSR Sprint cams. Let's say it was somewhat "challenging" to drive, at least as a street car. Very rev happy, very peaky, one had to keep it "up on the cams". I'm sure outstanding for its original intent, as a race motor, but maybe a little bit frustrating as a street motor. I just have to think that these changes will transform it into a wonderful street motor, without sacrificing its "personality" to any appreciable degree. I can't wait to see it.

bertj · 08-26-2022, 09:05 PM

Hi Brooke,

What was your power band like with DC62 cams and 46 PMO carbs?

Did you ever dyno the carb set up below?

I'm planning a similar build, but I don't know which cam to choose for street and canyon driving fun. Not high rev racing.

Thanks,

Quote:

Originally Posted by rswannabe

JP - yes, early turbo case, 66mm crank, Pauter rods, 95mm p’s & c’s, twin plugged 3.2 carrera heads, GHL 1 5/8 headers with heat into early sport muffler. I used to run RSR sprint cams, but couldn’t tune the 46 pmo carbs to be streetable and still make good use of all 8k rpm. I swapped in DC62’s for better streetability and dropped the redline to 7,500. With efi I can likely better tune across the rpm and I might go back to 8k cams, but one variable at a time.

rswannabe · 08-27-2022, 08:27 AM

Quote:

Originally Posted by bertj

Hi Brooke,

What was your power band like with DC62 cams and 46 PMO carbs?

Did you ever dyno the carb set up below?

I'm planning a similar build, but I don't know which cam to choose for street and canyon driving fun. Not high rev racing.

Thanks,

The problem with the RSR cams was that I had to run smaller chokes to keep the airflow sufficient for a good signal for the idle jets to keep it drivable at lower rpms, and those smaller chokes limited the power it could make up top. Thus when I did a top end rebuild I swapped to the DC62's to be more optimized for street driving.

With the higher ramp speeds of the DC62 cams compared to the RSR Sprint cams, I limited the redline to 7,500 (compared to 8,000 for the RSR Sprint cams) on the recommendation of John Dougherty. The benefit of the DC62 is that they move more air sooner in the RPM range and thus I could get a better signal for the carbs while using a larger choke. If I remember correctly, I was able to go from a 38mm choke for the RSR cams to a 40mm choke for the DC62's. The powerband started at about 4,000 rpm and pulled strong to 7,500. I never dyno'd the motor with the DC62 cams, so I don't have any graphs to share of the power curve.

bertj · 08-27-2022, 08:38 AM

Thanks Brooke. This is helpful feedback.

Did you flare the 1969 911 fenders or keep it narrow body with this potent engine?

I'm wondering if you had issues putting the power down.

Quote:

Originally Posted by rswannabe

The problem with the RSR cams was that I had to run smaller chokes to keep the airflow sufficient for a good signal for the idle jets to keep it drivable at lower rpms, and those smaller chokes limited the power it could make up top. Thus when I did a top end rebuild I swapped to the DC62's to be more optimized for street driving.

With the higher ramp speeds of the DC62 cams compared to the RSR Sprint cams, I limited the redline to 7,500 (compared to 8,000 for the RSR Sprint cams) on the recommendation of John Dougherty. The benefit of the DC62 is that they move more air sooner in the RPM range and thus I could get a better signal for the carbs while using a larger choke. If I remember correctly, I was able to go from a 38mm choke for the RSR cams to a 40mm choke for the DC62's. The powerband started at about 4,000 rpm and pulled strong to 7,500. I never dyno'd the motor with the DC62 cams, so I don't have any graphs to share of the power curve.

rswannabe · 08-27-2022, 10:25 AM

Bertj - While I did flare (ST) my '69, it was for the look and not out of a need to deal with more power.

I put the 2.8ss into my '69 when it was still a narrow body car. You can fit 225's in back in a narrow car and that is more than enough for even a hot rod motor. I even ran sticky 225's (Trofeo R's) on the car with the 370 hp 3.8 and they were able to cope with the power quite well. With modern tire compounds you do not have to flare a car to get good grip.

Here's the car when narrow with the 2.8.

Here's the car when ST flared.

bertj · 08-27-2022, 02:40 PM

Nice looking car, before and after.

I have 911R 7" wheels on the back of my narrow body 1970 911T and there is plenty of grip with my stock 2.2 T engine. I intend to use stickier rubber when the hot rod engine goes in. Either Avon or Michelin TB-15s.

I'm on a similar path to your car and it helps to get real world experience.

Thanks,

Quote:

Originally Posted by rswannabe

Bertj - While I did flare (ST) my '69, it was for the look and not out of a need to deal with more power.

I put the 2.8ss into my '69 when it was still a narrow body car. You can fit 225's in back in a narrow car and that is more than enough for even a hot rod motor. I even ran sticky 225's (Trofeo R's) on the car with the 370 hp 3.8 and they were able to cope with the power quite well. With modern tire compounds you do not have to flare a car to get good grip.

Here's the car when narrow with the 2.8.

Here's the car when ST flared.

rswannabe · 08-27-2022, 04:12 PM

I ran 7R’s on the back of my car when it was narrow. I also ran the Avon tires (after the pic above) and liked them a lot.

As I get older I find I like my cars to be slower and more playful (by that I mean less sticky) so they are more fun at sane speeds on the street. That’s one reason I removed the 3.8 from my ST and am putting the 2.8 back in.