2.8 RSR style twin plug engine

[Henry Schmidt]

Porsche 2.8 liter race engine. Built by Jerry Woods. This engine has less than 10 hours of running time. Mahle 92 mm Ps&Cs. Solid RSR rockers, factory 906 center feed cams. 40 mm intake and 39 mm exhaust ports. Cams, rockers and Ps& Cs all look like new. It was built on a 1977 2.7 case and is ready to go. Call or email with questions. Will freshen for small fee but I believe that would be a waste of money.
$6500.00 or best offer. Trades considered. If you collected parts to build your own engine, consider a trade and the day after delivery you are on the track.

[ubiquity0]

Would this run on street gas?

[Henry Schmidt]

ONLY IF YOUR STREET GAS IS 110 OCTANE.

[Alan Cottrill]

I know this isn't a technical post, but how is the valve lash adjusted on the solid rockers?

[Henry Schmidt]

The adjustment is made by replacing the lash cap. These caps come in varying thickness and are available through Porsche Motorsports. In a pinch you can use lash caps from an Alfa Romeo. The Alfa caps are easier to find and "surprise surprise" they're even cheaper.
The solid rocker engines rarely need adjustment after the initial adjustment and are worth the hassle they take to adjust. The rockers have a greater ratio 1.5 to 1 as opposed to the stock rocker which has a 1.4 to 1 ratio. Greater ratio means more lift and duration without a cam change. You can change the shims by removing the rocker or the tools shown below make this shim change a snap.
P7I and P7E are the part #s.. These tools also make it possible to replace valve springs and seals without removing the heads. If you're clever you don't even have to remove the engine from the car. I only recommend this procedure if you are only replacing one or to springs.

[gumba]

Any guess as to the h.p.?

[Henry Schmidt]

With 46 mm Webers and the correct exhaust I would guess 270 to 280 hp at the crank @ 10.5 to 1 compression.
Who knows?
Because I did not build this engine I am only guessing about the compression. It could have 10.5 to 1 or as much as 12.5 to 1. If they used an RSR piston in a 92 mm barrel designed to fit a 2.7 case, it could make huge compression and in turn make more horse power. RSR piston in a 2.7 head = 12.+ to 1 compression. RSR heads volume is around 76cc and the 2.7 head volume around 68 cc.

[Schuey]

Originally posted by Henry Schmidt
ONLY IF YOUR STREET GAS IS 110 OCTANE.

I thought with it being twin plugged it could? sorry for the dumb question

[Tricky D]

Henry,

You have e-mail.

[Henry Schmidt]

Originally posted by Schuey
I thought with it being twin plugged it could? sorry for the dumb question

There are no dumb questions. My response was based on the fact that it's better to be safe than sorry. I think this thing has big compression, and if it does, twin plug won't be enough to safely run on street gas. Even with twin plug I prefer to keep the compression around 9.5 to one on the street. The pump may say 91 but who knows?

[Tricky D]

All good points, Henry.

You have more e-mail.

[Henry Schmidt]

SOLD