Datsun Roadster Forum-311s.org

Hey gurus...

Any of you guys have any experience with or no anything or a little about stroking a U20

I my about to pull the U20 motor and 5-Speed tranny to take a look see. I have not heard of anyone stroking a U20.

How much can U20 can be stroked to If a 1600 can be stroked to 2000 then I guess proportionately a 2000 can be stroked to a 2400-ish.

What parts need to be replaced Cam, heads, bearings, etc...

What parts need to be machined Block... etc...

What increase in torq, HP, and heat can I expect No clue?

Is it worth it Costs to gains ratio, pros & cons, bragging rights, etc...

Thanks..

If you can find a way to stroke a U20 that would be cool. Here are the problems that I can see off the top of my head. What crank would you use? Also you will have to buy custom connecting rods. Low compression custom pistons will also be in order as the compression will be through the roof (stock is 9.6:1) you stroke that and it will be unstreetable. Running a custom cam with extra overlap might help bring the compression down but I don't know how much. The head is a great design but could/will warp if you get to crazy.
Have fun and good luck,

Will

Yeah, I don't think you are going to be able to stroke a U20. The U20 is really nothing more than a stroked 1600 with a different head, cam, crankshaft, connecting rods and pistons. You could overbore the block putting bigger pistons, B cam and Solexes to pump up the HP. You would be better off pursuing one of the other conversions such as the KA24 or the VG30. Probably a lot cheaper too! I think there are a couple of turbo-charged U20s out there but then again-speed equals lots of dollars. Maybe someone else has other ideas but I would pursue other options unless of course money is no problem.

Steve

Makes a lot of sense... This would explain a lot why I have not heard of any stroked U20s.

Yes, I did think or consider of about boring out and putting biggger pistions going with Webers or TWMs. I will let you all know in a about a month what I decide...

I have already decided to go Shelby 289 if I ever decided to swap (I've always dreamed having a Shelby Cobra/Tiger/Mustang). I gonna make my own 289 Tiger. I think the Datsun is a much better car for the Ford 289 motor.

Thanks...

My U 20 is bored .040 over with solexs, a B cam, and an 11 lb flywheel and my car is a rocket. Some guy in a riced out Civic wanted to have a go at it on an onramp, the light turned green and he got dropped faster than you can say rice burner.

Will

Thanks...

That pretty much the outcome effect I am trying to pursue

Boring, flywheel, and carbs should do the trick.

As far as manifold. Do I have too have the manifold? Can't I just use a adaptor plate to mount the carbs?

Oh.. I left out he B-Cam

You do need the intake manifold for the solexs. They are indevidually run to each cylinder from each throat of the carbs. You could get some more power if you spent some cash on custom pistons that would raise compression to about 10:1 with a set of TOTAL SEAL rings. I was breefly exploring that option but decided to just rebuild what I had. The light flywheel is cool, very pricy but very cool. If you do some head work as well you should be able to pick up quite a bit of power. The BOB SHARP COMPITITION PREP MANUAL will tell you how to do it. I think you can down load that from DATSUN.ORG. I am also running a 2 inch exhasust through a glasspack and a supertrapp. It seems to work well, doesn't sound bad either.
Will

Did you put the Glass Pack and SuperTrap next to the gas tank?

Or,

Did you put the Glass pack uner the driver's seat and the SuperTrap next to the gas tank?

How many plates do you have on the SuperTrap?

Thanks..

I have the glasspack under the driver seat and the supertrapp as the tip. It is a short supertrapp and I am running 6 plates, I had all 12 but I pulled 6 off to see how loud it was, I haven't driven it much due to a massive oil leak from between the timing cover and the head. I need to pull the engine to fix it. I think the glasspack is about 18 inches long (I haven't measured, just an eye ball guess.)

Will