Actually, Craig Hooper has been having a guy build exactly that for some time
now. Part of the
motivation for the switch (as I understand it) was that he wanted to run a
belt-driven supercharger.
The engine has been dry-sumped and the belt is external. Besides the
fabrication difficulties, I
think the biggest drawback is that it requires cutting the front portion off
the head, thus
rendering it unusable for a regular U20.
jerry gallagher wrote:
> I've been on the roadster list for about 7 years and have seen many posts
> about the 2L timing chain setup. I've been wondering just about as long if
> there are any alternatives.
>
> So I'm going to contribute this free idea and perhaps my flawed knowledge of
> things automotive will be brought to light(not too much risk of that not
> happening with this group but hey this is roadster related so be gentle)
> and I can spend my time thinking of other things.
>
> 1.) the 2L's performance seems to suffer from the weight of two timing
> chains and four timing gears.
> 2.) many newer cars have timing belts. A belt of the same length weighs
> much less than a double-row chain
> 3.) many racing Alfas use a single row chain instead of the normal
> double-row chain. Has anyone ever heard of a 2L running a single row chain?
> 4.) with the abundance of cars using timing belts these days is it lunacy
> to think that out there somewhere there is a combination of timing gears and
> timing belts and tensioners that could be adapted to the 2L to perhaps
> lighten the valve train and increase performance. Perhaps there is a
> permanent solution to the 2L death rattle waiting to be found out there --
> maybe it would cost less the replacing the timing
> chains/tensioners/gears/guides with stock parts.
> 5.) the biggest issue I can identify about this being possible, making the
> assumption that item #4 is true, would be how to create a dry environment
> for the belts since oil and timing belts are not a good combination (there
> are some things you don't want to slip).
> 6.) If I remember correctly the reduction from crank speed occurs between
> the crank and the jackshaft. The jackshaft to cam is a 1:1 ratio.
>
> Am I volunteering to use my own car -- no. I rebuilt the engine 8 years ago
> and the car gets about 1,000 miles a year -- probably less this year since
> I'm using my Alfa gtv6 as my daily driver. I fully expect the stock setup
> to last quite a while -- bought everything new from a Nissan dealer, right
> down to new lock tabs for the tensioners.
>
> going to get the nomex on now (former racer? no, used to own a pinto)
>
> hope you all have a good weekend
>
> Jerry
> '69 SRL311 xxxx7
> '86 alfa romeo gtv6
--
Gordon Glasgow
http://www.gordon-glasgow.org
|