GPZ600R engine building for big power...weakest links? - Kawasaki Motorcycle Forums
Reply
 
LinkBack Thread Tools
post #1 of 12 (permalink) Old 08-05-2016, 09:27 PM Thread Starter
Needs more boost!
 
KawiWowie's Avatar
 
Join Date: Aug 2015
Location: SoCal
Posts: 22
GPZ600R engine building for big power...weakest links?

And by "big" I mean perhaps doubling the stock ~76bhp figure.

I'm not a n00b to engines by any means, but I have never had a GPZ600R apart. Based on my limited research and some reading in the manual, it looks like pitted rockers are a something to look out for. The silent chain primary drive is also something that makes me go "hmmm."

Despite that, I like the vintage appeal and the sound of these engines and want to explore adapting EFI and forced induction to one. Has anyone here tried this sort of thing on this specific engine or know of any good reading on the topic?
KawiWowie is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 08-06-2016, 06:40 PM
Senior Member
BTK Expert
 
Join Date: Oct 2004
Posts: 1,361
Doubt this is the place to ask your questions as most of the bikes here are air cooled and carbureted vintage models. Not a lot of know-how on doing the things you are looking for, I am afraid. If wrong, and someone jumps up to answer, my mistake...

wiredgeorge
Texas Hill Country
wiredgeorge is offline  
post #3 of 12 (permalink) Old 08-06-2016, 09:40 PM Thread Starter
Needs more boost!
 
KawiWowie's Avatar
 
Join Date: Aug 2015
Location: SoCal
Posts: 22
Yeah, it was a calculated risk since most of the good GPZR information I have found is in this forum.
KawiWowie is offline  
Sponsored Links
Advertisement
 
post #4 of 12 (permalink) Old 08-07-2016, 12:36 PM
Senior Member
BTK Expert
 
Join Date: Oct 2004
Posts: 1,361
The mechanics forum might a better place...

wiredgeorge
Texas Hill Country
wiredgeorge is offline  
post #5 of 12 (permalink) Old 08-07-2016, 02:00 PM
Senior Member
BTK Expert
 
Join Date: Mar 2009
Posts: 4,807
Is this type of modification cost effective/practical? Never, especially when you can buy the extra horsepower with just an increase in displacement, without all of the headaches.
sfair is offline  
post #6 of 12 (permalink) Old 09-05-2016, 01:33 AM Thread Starter
Needs more boost!
 
KawiWowie's Avatar
 
Join Date: Aug 2015
Location: SoCal
Posts: 22
Quote:
Originally Posted by sfair View Post
Is this type of modification cost effective/practical? Never, especially when you can buy the extra horsepower with just an increase in displacement, without all of the headaches.
With that kind of answer, it's obvious I'm looking in the wrong forum...
KawiWowie is offline  
post #7 of 12 (permalink) Old 09-05-2016, 10:38 PM
itching to ride
BTK Expert
 
kawpaul's Avatar
 
Join Date: Aug 2009
Location: TN
Posts: 2,204
These engines are already almost at maximum output. Using forced induction would be the only way imo and I doubt the bottom end could hold up to the boost. I would agree with sfair, it would be easier to just get a different bike if your goal is to get around 150 hp.

If you choose to go that route however I would love to see your work and I am sure others here would as well. If you decide on a different forum then be kind and post the link in this thread so we can go have a look.

1986 LTD 454
kawpaul is offline  
post #8 of 12 (permalink) Old 09-10-2016, 05:56 PM Thread Starter
Needs more boost!
 
KawiWowie's Avatar
 
Join Date: Aug 2015
Location: SoCal
Posts: 22
Quote:
Originally Posted by KawiWowie View Post
With that kind of answer, it's obvious I'm looking in the wrong forum...
Sfair, I didn't mean to sound insulting, BTW. It's just so frequent that someone not taking the easy way is met with defeatism, particularly relative to motorcycles with the stock answer being "get a bigger bike." I ride the road less traveled. There's less traffic.

You should see one of my four-legged projects. It makes turbocharging an old GPZ look like a fairly modest endeavour.

Quote:
Originally Posted by kawpaul View Post
These engines are already almost at maximum output. Using forced induction would be the only way imo and I doubt the bottom end could hold up to the boost. I would agree with sfair, it would be easier to just get a different bike if your goal is to get around 150 hp.

If you choose to go that route however I would love to see your work and I am sure others here would as well. If you decide on a different forum then be kind and post the link in this thread so we can go have a look.
There isn't really a goal per se except for maybe avoidance of immediate failure.

I thought forced induction was the obvious choice too as among my collection is a Garrett GT15 that would be sized well for 120-150bhp and ~14-15psi of boost. The engine is already rated at 76bhp, so 15psi with intercooling should about double it and 8psi ought to make a comfortable 120hp. In reality I have enough hardware to do far more sinister things to an engine.
Attached Images
File Type: jpg hairdryers_R_us.jpg (50.5 KB, 3 views)
File Type: jpg this_blows_zpskfa8dwf8.jpg~original.jpg (56.3 KB, 3 views)
KawiWowie is offline  
post #9 of 12 (permalink) Old 09-23-2016, 11:36 PM
itching to ride
BTK Expert
 
kawpaul's Avatar
 
Join Date: Aug 2009
Location: TN
Posts: 2,204
Yeah 15 pounds will about double your hp as atmospheric pressure is 14.7 at sea level. of course running that much boost I would think the compression would of necessity have to be lowered which would also drop the starting hp prior to boost.

1986 LTD 454
kawpaul is offline  
post #10 of 12 (permalink) Old 09-29-2016, 08:50 PM Thread Starter
Needs more boost!
 
KawiWowie's Avatar
 
Join Date: Aug 2015
Location: SoCal
Posts: 22
Stock compression ratio is 11.0:1, right? I think it would tolerate 15psi with intercooling and good pump gas if not a splash of 100 for safety. It would make the effective compression ratio about 22:1. 20:1 is pushing it for car engines, but the high RPM and smaller chambers of the GPZ will make it less prone to pinging. Water injection is another option.
KawiWowie is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome