240260280z

I think you could drive on highways all the way across Canada w/o a toll. Land of the Free .... and high taxes

AA Pistons finally arrived. Compared to an 86mm Nissan flat top piston: The top ring is 0.7mm lower so shaving the top will not place it too high. It is interesting that the arrows on a type 1 VW piston point to the fly wheel but the engine turns CW relative to the front of the crank... so the arrows will have to also point to the FW on the Z to get the thrust offset correct. The pistons do not have oil holes in the pin boss so that will have to be added. The Nissan pistons have a centre hole drilled in the oil ring gap but these do not. The Nissan pistons have a steel insert. Both have slots in the oil ring gap. 7.9mm crown thickness on Nissan and 8.0mm on AA

Source:http://www.theminiforum.co.uk/forums/topic/256865-dvizard-tuning-bls-a-series-and-twin-carbs/page-2 "The reason for having ‘Fast drop’ piston is to allow the piston to drop during gear changes. If the piston does not drop fast enough during a gear change the needle will not be in the correct position to fuel the engine when the throttle is opened again after the next gear is selected. The result of this is a huge flat spot between gear changes." "?The aim is to spring the carb such that it is fully open as you reach maximum power." "As the SU does not have a accelerator pump jet extra enrichment during acceleration is catered for by slowing the piston rise when the throttle is opened. This retardation in the piston rise causes the amount of ‘Pull’ on the fuel leaving the jet to increase and thus more fuel is drawn off and this enriches the mixture during the acceleration phase. Common misunderstanding is that to gain greater performance you can thin out the oil within the dash pot to allow the piston to rise faster and gain greater acceleration. While true to a point it misses out the fundamental point of fuel economy. In order to gain the best fuel economy and performance, the needle used must be chosen such that at any steady state running point it is fuelling the engine correctly. Enrichment during acceleration is purely catered for by the Damper assembly within the carb. Modifying the damper by thinning the oil for example in this case would mean that the amount of enrichment would be reduced during acceleration and possibly cause a flat spot. Now using this thinner oil coupled with a richer needle would mean that the fuel enrichment balance during acceleration would now be restored and because the piston rise is quicker we will notice an increase in the acceleration when we put our foot down. This is what usually happens when most minis are rolling road tuned. The needle is a little too rich during normal running and about perfect during acceleration. This is great if you don’t mind paying for the extra fuel!!! 10mpg less is common for this way of setting the SU up! "

The throat is also tapered. Info here: http://www.vintageracerules.com/forums/ubbthreads.php/topics/10176/CFM,_vs_HP

It would be interesting to know know more about the ss valves.

Red Block in the language of speed.

corpo rosso!

su tapered piston

SU Mod Info on this site: http://www.classiczcars.com/topic/40478-su-mod-lifted-from-the-net/

I bet customizing stock needles in a drill press will be worth doing.

I agree. O would miss the fresh air too much too....but I saw it on an autocross racers page and thought it was worth sharing none the less.

Sell your research back to Rebello who should have done this years ago.

Give Montana regards from my Blue 77.... point of origin.

FYI I have a friend who just installed a Pertronix points conversion. It lasted ~ 30min.

I'm interested in parts if it is pre-jan71. /thx

Dead head and set fuel pressure to 3.5psi. You can then focus on the carbs and not worry about fuel.

I think Jeff Priddy owns the only set in the world. Here is what he says: Just a little history, David Webber at Malvern was working on these parts in a Nissan application in 1999. As you know David has passed away, so my only other contact was the guy that did all of the R&D on the project. I was able to get his phone number yesterday, and gave him a call. Seems his shop is no longer in business, and he was not home. I would like to get his information on the project and what the final outcome was. I am going to wait on letting the manufacturer out on this one to save the guy from getting inundated with lookieloos. This is not going to be a cheap build at this point. After all of the R&D is completed and all the NRE charges are paid we will see just what the setup can be bought for.

From a book on performance tuning: I think it initially comes from oil/carbon deposits that were never removed and eventually cooked over the years. It can initially be deposited as oil from leaking valve seals or passing the rings. I see similar when I clean the tubes in my oil fired furnace.

I'd like first refusal on the l24 if it is an early one. Vin147 needs a benefactor.

Ash from combustion.

You may consider flushing the oil bar with carb cleaner until only clear fluid leaves. Use the straw to spray into each hole as well as through the cam oil holes. Flush forward and backward and hold the bar up at 45 degrees with one end on the ground/catch pan then do the same with the other end.

I said A$$ and the forum changed it to arse.

But the same cop watches 100 people each day texting and driving.... maybe even a family member. The law is an arse.