2.7 7R case converted to 2.0

[Henry Schmidt]

Here's a quick look at one of our new services. We can sleeve the 2.7 7R case to fit 2.0, 2.2 and 2.4 cylinders. This can also be used to bring your early case back to specs after it was bored to fit 90mm cylinders. Restore your valuable 2.2 "S" case back to stock. Restore your 2.0 aluminum case back to 2.0 after a 2.5 conversion.

[blue72s]

Good work!

Can you sleeve the ports of 2.8RSR heads?

[Henry Schmidt]

Originally posted by blue72s
Good work!

Can you sleeve the ports of 2.8RSR heads?

Yes, we have resized over ported heads that seem to be prevalent in early 911 home built racers. Although I agree that 43 mm ports on a 2.8 engine are excessive, are you certain you want to modify real 2.8 RSR heads?

[kenikh]

Oh, THAT ROCKS. How much?

[YTNUKLR]

Awesome stuff Henry...!

Can you give out any details or is this top-secret?

[Shuie]

Brilliant!

[Plavan]

Henry,
What about the different expansion rates of the metals? Has there been any long term testing? What do you use to "glue" the "insert" in?
Looks nice.

[Henry Schmidt]

As with all other modifications we choose to explore, we thought of that and did some research. What we found was that the difference in the expansion coefficient is very little.
It is almost impossible for us to calculate the true expansion coefficient of the magnesium because we don't know the alloy mix but pure magnesium is around 26.1 x 10-6/K and we know it's an alloy so the EC should be lower. The Expansion Coefficient of aluminum is 20.4-25.0 x 10-6/K depending on alloy mix. As you can see it's very close so it should and has had no noticeable effect.
As for glue: not being adhesive engineers we thought it prudent to seek the help of one. We called E. V. Roberts, an aerospace composites company, and got some advise. Their engineer recommended an adhesive that they use to bond carbon fiber to aluminum. Two completely different materials with two completely different ECs. That is the adhesive we chose.
At this time we have this modification in three engines [one a 2.0 race engine] now for over two years.

[Wayne 962]

That is very cool indeed! I can't imagine too many cases (pun intended) where people would want to remove horsepower from their engine, but I'm sure for racing circuits there is indeed an application for it.

-Wayne

[YTNUKLR]

I had a set of 2.5L Long-stroke Mahle P/C (86.7mm, 10.3:1 C/R, 911ST parts), and the spigot would have to be 94.1mm to run those. Many interested parties were interested at first, but not after they find out about the necessary spigot mod. This would allow people to run that set and take their case back to stock if desired (duh). Just felt like sharing!

[YTNUKLR]

I had a set of 2.5L Long-stroke Mahle P/C (86.7mm, 10.3:1 C/R, 911ST parts), and the spigot would have to be 94.1mm to run those. Many interested parties were interested at first, but not after they find out about the necessary spigot mod. This would allow people to run that set and take their case back to stock if desired (duh). Just felt like sharing!

[BReyes]

I would be interested in seeing the data on testing. The services seem to be a promising opportunity for those who want it.

Good luck.

Regards,