Radical streetable engine size

les holt wrote: I've seen the bike go mid 8's in street trim. Dot tire and no bar. Won't give details but seen flow #'s on the head which is a 900 head and know the all motor dyno numbers. Won't show a pic, it's a nasty sleeper.

Les

You big tease Les!

Tell ya what, come to Indy, bring cash, lots of it! and when it's all said and done, He might give a little insite! I do know this, it done lots of street battles around chicago in its prior life and it isn't pretty, just fast!!!

Les

Sounds like a pretty serious grudge bike. 1500cc on the street . Can you say booooiiiinnnnggg !!!

les holt wrote: Bellucci head, turbo pistons. Went 219 all motor, won't say what on spray but its NASTY!

Les

219HP?

Dyno Jet Dyno?

Valve Sizes?

What was the peak HP RPM?

Carb Size?

A 1428 motor wants about 113CFM@10" to produce a potential 218 @8500. That's a trapped Ve of 125. Pretty stout ;) To get that takes an intake valve that requires over size seats. Not much sense in putting that kind of money in an old 900 head but hey...that's JMO. :)

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 ?