Radical streetable engine size

I assumed 219 meant MPH... :laugh:

Lorcan wrote: I assumed 219 meant MPH... :laugh:

You may be correct but somehow I doubt an old unfaired Z is going to pull 219 MPH. If it does, I'm sure as hell impressed. Come to think of it if it makes 219 HP I'm impressed. Well done either way

219mph on an unfaired KZ would take a
strong son of a bitch just to hang on to it.

Anyone running a 1428 on the street ? Also I see over at the kz zone they list a 1425 kit for use with the kz engine and the kz head then they list a 1428 kit for the kz engine with the J model head. What's the difference in the kz head and the J model head and which head is better ?

The difference is in the piston pin locations. Putting a J head on a KZ bottom end will reduce compression ratio. Therefore that has to be addressed.

J and GPz bathtub heads require less work to make power than a KZ head requires on a large cc motor.

I know an old piece of crap drag bike that will probably spew it's crankshaft all over the track sometime soon that runs 5.70's 1/8 mile steadily with less than .460 lift cams, small tire & bar, anciennt 38 trons, 1327cc, J head with 39/32 combo. The bike is old. The guy has no money....

Excessive heat and/or lack of lubrication are your motor's greatest enemies. Keep that in mind when you build you radical, streetable engine

So is it better to invest the money in the KZ head because I already own one or get a J head and throw money at it What's the best bang for your buck. How about compression ratio, I don't see many talking about that. Ultra 94 Sunoco gas is about the best pump gas around. Where compression ratio do you start running into detonation issue with the KZ ? How about getting them started ?? Stock starter hold up to a 1327 or a 1428 ?

my stock starter would barely handle my 1327. It actually made my sprag unit go out. With a j model head you will lose right around 2 points of compression. If it was me i would get a j model head. But you do have to buy a idler adapter and the jig to locate the holes properly.

So how did you solve the starter issue powerstroke ?

For the starter, you can use the starter out of a CB1000 Honda. Look for the one that is .8KW. Lots of then are of the .7KW rating. I've heard that a GPZ starter is stronger but I don't know about that one. Lots of racers use a Cashio starter. He rewinds them to be stronger. I think they are for 24V but not sure. You'd have to check that one out to be sure. The popular option is the Honda starter though. Heard it's a bolt in...may need to adjust the cable bolt position though.

I posted a thread about doing the same with my GPz vs selling it. I didn't get any replies so I searched further, mostly in drag forums. Apparently the 1428 is not street-able due to not surviving street level heat according to several posts.

Now if there is a 1500 on the road I would love to learn more cause Les is teasing us worse than our 14 year old girlfriend back in JR high.. :ohmy:

The bike is street ridden and really pretty easily but not often. With the time and money in that thing I suspect he doesn't want to waste too much of it's life on needless play. It's a purpose built motor with taking your money being it's main goal. He'll ride it where you want to go just to show you it's not a big bad wolf only to take your goodies. NOT TEASING! it's a serious piece.

Les

I know of one 1428 on the street, small cams and lower compression (9 to 1) because of over heating and pump gas. It's ridden ocassionally about 500 miles a year. Impressive when he fires it. Doesn't run bad, either.

don