Honing cam bushings

How do I reach out to ZED1015 concerning j model head configuration you speak of?

This is a J head which simply needs the top idler modification ( the red bit ) for it to fit any earlier Z9/1000 engine.
The stock 40cc combustion chamber volume is 4cc larger than the earlier (36cc) heads so will need steps taken to correct this such as skimming it approx 1.3mm or using higher comp pistons .
This head is now on my recently completed Racecrafters build which can be seen elsewhere on the forum.
It is 1075cc and i used 12-1 comp rated wiseco's to get the actual comp to around 10.5 to 1 and the head is ported with 90% throats and 32mm / 37.8 mm stainless valves.
Done correctly the J head is a worthwhile mod on any capacity Z9/1000 engine and i suspect the advice regarding the use of the J head on larger engines was because the early KZ head cannot flow enough for a normally aspirated big bore engine above around 1200 cc no matter how much it is ported and becomes the main cause of restriction for making further power.

The  pics in the second post is my current turbo build which will also use a J head.
This is also 1075cc and i'm using 10.25 -1 wisecos and a barrel spacer of yet undetermined thickness to get the comp down to around 8-1.
This will use 33mm/37mm valves with 90% throats and the porting focused on the exhaust side .





 

  
 

Hail 1015!! I know expertise when i see it, what do does that 90percent on porting mean, i still Need to learn!

I used a similar J-head on the last normally aspirated 1428 Z i did for myself waay back in 95. But never finished it, sold. Had a Friend since deceased that used to do pro-stock drag events, do the porting valve seat enlargement etc. But back then i was doing construction, just handed over the greens. Cool You Know Sooo Much, if i can fleet some worthless synapses that don't amount to a pile of shite. I would Love to be the intern of the wealth of Your Knowledge!! I have my specialties too but lacking in Your trade set of performance.     

asphalt900 wrote:

Hail 1015!! I know expertise when i see it, what do does that 90percent on porting mean, i still Need to learn!

Just fitting bigger valves won't show any benefit unless the throats ( the part of the seat the fuel mix encounters just before the 60 degree cut of a normal 3 angle valve job ) are enlarged too for increased flow and then blended into the bowl . 
Depending on application the throat is enlarged by a percentage of the valve diameter and going too big can actually reduce the flow rate to less than the stock head. 
With a two-valve head, 90% of the valve diameter is ideal for all-around throttle response, acceleration and best average power.
If your throat goes over 92% valve diameter, you begin to lose horsepower quickly so 90% is a nice safe number for general home porting especially if you haven't got access to a flow bench.

This is 90% on the J head.

Looks like a BHP distributor

sflaZ1T wrote:

Looks like a BHP distributor

Yes.
It's the boost retard version.
Don't see many around, especially here in the UK.
Ran one on the drag bike with great results and managed to gather enough parts over the years to build a real nice one for the Moriwaki build and another for spare.



 

Awesome information ZED1015, and thanks for sharing it 👍
Rich.

I´m running a ported J head with UT cams and adjustable UT cam sprockets. You need allen head screws to fasten the UT sprockets.
Hex srcew heads will collide with the roller cam chain links!!!
Pic shows Z1 cams and adjustable sprockets. As ZED1025 mentioned, on stock piston setup you get only 8-1 compression = turbo setup.

 
 
 

 

Amazing stuff Zed!! How did You "fall" into this hobby? There are NO schools for this stuff. It's generally the school of hard knocks and a lot of mistakes till the Bulb illuminates, shazam. 

asphalt900 wrote:

Amazing stuff Zed!! How did You "fall" into this hobby? There are NO schools for this stuff. It's generally the school of hard knocks and a lot of mistakes till the Bulb illuminates, shazam. 

 
Yes! THIS  /\   /\   /\   /\   /\  exactly.
Almost all self taught because i either could never afford to pay someone to do what i wanted or any work i did pay for was disappointing and not to the standard they claimed so i figured if a job is going to get f*cked up i may as well f*ck it up myself for free and at some point you actually get half decent at stuff without realising it.