'New' 2.7 RS Motor Installed in '73S

After a 2.5 month hiatus, I finally got the car back with the new motor. The majority of the wait was for the MFI fuel pump rebuilt by Gus at Pacific. You guys were right about being patient.

The donor motor was from a '77. The top and bottom were competely redone - and the works balanced. Factory RS pistons were used, the heads were fly cut, and an E cam was added for better bottom-end (its not a race car.) A larger turbo oil pump was added to aid in flow and reduce hp loss due to scavanging. The original MFI system was cleaned and reinstalled along with a Pertronix electric ignition. Every nut and bolt was replaced as well as the addition of ARP head studs.

SSIs and a stainless sport exhaust crowned it off. New shifter bearings and a gate shift kit.

The review - the car runs like a sewing machine with a nice growl. Since I have less than 150 miles on it, I'm keeping the revs to 5000 and less until about 500 miles, and then bump it to to 6 grand. It has silky smooth acceleration, but is not startlingly different in acceleration from the 2.4 S motor it replaced - just a bit more pick up, at least to 5 grand. (It's no turbo) I was told, and need your opinion, that once the motor breaks in and is seated, that I will pick up a few more ponies. Also what is the engineering behind recommending that the RPMs be varied during break in?

Right now I am extremely pleased with the result and am looking forward to breaking it in on the way to Monterey. Hope the Marriot doesn't mind an oil change in the parking lot.
;)

Larry,

Having just (kind-a) done what you have about 3000 miles ago…

Both the perception and reality of your new motor will get better and better…

The reality is… As the rings and valves seat the cylinder pressures will build and the engine will indeed run stronger…

The perception is…While running a break-in procedure at a limited RPM, you are getting only a percentage of the total experience… only a chorus of the whole song. Only when you are able to run the car to the limiter will you realize what’s-up. That last 15 to 20% REALLY makes a difference to whole experience.

Sounds like you’re doing everything right … have patents ;)

Congrats and good luck ... (from Florida:cool: )

Larry,

I had a full on 2.7RS spec. motor built several years ago (just ticked over 40K this week).
After a few oil changes and 1500 or so miles I was delighted with the new unit. I must say she runs as strong as ever.

Curious. When the MFI pump was rebuilt/refreshed, what specification was it built to i.e. 2.4S, or 2.7RS, etc. to run with the E cams? Typically the pump, cam, and displacement are all matched, the RS having S cams. I've driven a 2.7 with E cams and Webers, but not MFI. More torque, less top end as I would expect. My 2.5 (86x70.4) 914-6 has E cams and nice midrange torque. The RS motor will run all day at 4000+rpm and feels great doing so.

Sounds fun.

Tom Wilkinson
1970 914-6 2.5
1973 911 2.7RS spec.

Rick, Congratulations! You have not really experienced what this motor will do, while you are keeping it under 5000 on the tach. It is the spin up from there to 7200 that is the 2.7RS. Once you finish with your break-in (just change your oil now and again at 500 miles), then you can really experience the motor. Have fun driving it to Monterey!

The words of encouragement after break-in sounds better than I feel right now, which is mildy disappointed. I certainly don' t miss the oily smoke, the clatter, and the rusted through heat exchangers. "What honey, you'd rather freeze to death than be slowly asphixiated?" Her response, "At least when they found me I wouldn't stink!" What I do love is the silky smooth power up to 4 grand. I can't wait to hear it and feel it at full song, and just knowing that the power will be there is something to look forward to - especially after 40 thousand miles.

a911 - the MFI pump as rebuilt to RS specs. The gentleman who built the motor has done 3 of them with E-cams and the owners I have talked to really like the power, but then none of the cars are full-on race cars either. He is building the exact same setup, with LSD, for his metalic silver '72 T coupe. Wish I could have added that as well but another 2,500 was just getting out of control.... exceeding the purchase price of the car. Now I know why people look for the best examples they can afford since the restoration/hot rodding costs can far outweigh a pristine car - but then, that was the best car I could afford at the time.

Living to wind it out! Motor On!

Rick,

My rebuild took 8 months… once I started the 500, 1500, 2500 miles break-in procedure last Dec. I just kept at it… I’d get home after work and try to put about 100 miles or more on it every day and much more on the weekends… until it was ‘mine’…

Starting in January through February and into March I started receiving the gas credit card bills for the 91 octane I was putting in it ever other day…..WOW!!!!!!

One more expense of the rebuild I didn’t figure in …Ya-know, by then I was having so much fun with my ‘new’ car I didn’t much care…

Stay at it buddy… ;)