Super 90 or 1720cc?

[Tatzentier]

If you have standard 75hp 1600cc B engine and want a little bit more power (not for racing, just to make things more exciting), which way is preferable: Trying to upgrade the engine with original parts to Super 90 spec. or buying on of the aftermarket big bore sets (like Shasta), which take the displacement to 1720cc. What is needed to create a Super 90 or SC engine: Heads, valves, carbs or even a new crank case?
Any opinions?

[mein12]

Hi,
Without going into too much detail, the big bore kit with SC heads is by far the easiest and most productive route.
You might consider a different cam as well.
You will have to find some carburettors. The 40PII works well and is an instant match for your stock application. It can also be modified for more spirited pursuits later.
The super 90 is a breed apart and the pries for parts reflect that. The "90" motor would run great, but not better than the "SC" clone that we are discussing here.
The money you save will pay for the carbs and exhaust.

Good Luck, JMB....

[Roland Kunz]

Hello

The super 90 was a rev happy engine and made the power wher the standard was on the peak down curve.

The standard crank will not like to be reved to high under load.

So creating a Super engine needs the super crank.

I would recomend to fish for a good and complete 63on SC or 912 engine. ( 616/36 )

"High" volume oilpump and all the stuff is close to bullet proof.

I never had Shatas in my hand but if they are like the NPR´s they are usable as long you know how to use them. Most important is to CC and check if the piston will hit a valve or even the spark plug.

Grüsse

[mein12]

Roland,

The Shasta piston is produced by JE in California and sold by Duane Spencer. It is a forged, low expansion alloy piston. It is far superior to an NPR cast piston.
I have used these pistons with carillo rods, lightened wristpins, a counterweighted (sc)crank and 12 to 1 compression to produce 7500 rpm high output engines.
I have never had a major failure on track. I really like these pistons.
FYI, JMB....

[echocanyons]

Does JE have a phone number or a web site?
I am looking for a set of p/c's and think that this might be the place.
Thanks,
Kelly

[mein12]

Hi,
The man who designed the pistons and sells them is Duane Spencer. He can be reached at (530) 238-2198.
Check out his website. www.shastadesign.com

Good Luck, JMB....

[Joe Bob]

A buddy of mine just did that upgrade, he loves it....

BTW, if you do the deed, I have a nice complete set of Solex P-40s solid shaft carbs available....

[ScotMcLean]

Hi - I've got a set of SC/912 heads, complete 912 case + counter-balanced 912 crank available. Here is my email address:

scotmclean@yahoo.com

Scott
69 912 #23078
68 912 sunroof
67 912 project