R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road > Onroad Nitro Engine Zone

Reply
 
Thread Tools Search this Thread
Old 03-15-2012, 03:23 PM   #1
Tech Apprentice
 
Join Date: Mar 2012
Posts: 95
Default TZ-18 Timing Question

I just read an older thread ("how to adjust engine timing"), which is very interesting. I have been "some-what modifying" these little engines for years, and after destroying many, I figured out how to make them scream. They even start and idle without stalling constantly. However, I never knew about the "timing adjustment" associated with them. So I have a few questions to all persons knowledgeable of engine timing; what is the stock timing of the OS TZ-18, and should the recommended 2mm cut be made on the opening or closing side of the crank. I have always simply trimmed metal off (knife edged) the closing side of the crank, but left the stock timing alone. Further, what is the best timing for a drag race only (TZ-18) engine, and how do you balance the crankshafts? Thanks
Z'Stein is offline   Reply With Quote
Old 03-18-2012, 01:42 AM   #2
Tech Apprentice
 
Join Date: Mar 2012
Posts: 95
Default

Wow!! Sorry for asking.
Z'Stein is offline   Reply With Quote
Old 03-18-2012, 03:05 PM   #3
Tech Master
 
Grinder's Avatar
R/C Tech Elite Subscriber
 
Join Date: Feb 2003
Posts: 1,857
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by Z'Stein View Post
I just read an older thread ("how to adjust engine timing"), which is very interesting. I have been "some-what modifying" these little engines for years, and after destroying many, I figured out how to make them scream. They even start and idle without stalling constantly. However, I never knew about the "timing adjustment" associated with them. So I have a few questions to all persons knowledgeable of engine timing; what is the stock timing of the OS TZ-18, and should the recommended 2mm cut be made on the opening or closing side of the crank. I have always simply trimmed metal off (knife edged) the closing side of the crank, but left the stock timing alone. Further, what is the best timing for a drag race only (TZ-18) engine, and how do you balance the crankshafts? Thanks
Stock TZ.18 timing is as follows:

Crankshaft open 38 degrees abdc
Crankshaft close 60 degrees atdc
Crankshaft total open 202 degrees

Transfers, and boost are open for 120 degrees. Open 115 atdc.
Exhaust open for 168 degrees. Open at 95 atdc.

I don't want to disclose my exact crank numbers for my modified TZ.18, but you should start by removing .75mm from opening, and closing.

You should also enlarge the bore of the crankshaft, and add a tungsten weight to the crank.

How I balance is something I will keep to myself. Sometimes crankshafts need weight removed from certain areas. Sometimes I need to add tungsten weights to certain areas. A lot of the time, I do both.
__________________
www.murnanmodified.com
Grinder is offline   Reply With Quote
Old 03-19-2012, 02:34 AM   #4
Tech Apprentice
 
Join Date: Mar 2012
Posts: 95
Default

Quote:
Originally Posted by Grinder View Post
Stock TZ.18 timing is as follows:

Crankshaft open 38 degrees abdc
Crankshaft close 60 degrees atdc
Crankshaft total open 202 degrees

Transfers, and boost are open for 120 degrees. Open 115 atdc.
Exhaust open for 168 degrees. Open at 95 atdc.

I don't want to disclose my exact crank numbers for my modified TZ.18, but you should start by removing .75mm from opening, and closing.

You should also enlarge the bore of the crankshaft, and add a tungsten weight to the crank.

How I balance is something I will keep to myself. Sometimes crankshafts need weight removed from certain areas. Sometimes I need to add tungsten weights to certain areas. A lot of the time, I do both.
Thank you for your response. I have never had a professionally modified motor, but based on your response, I think I may need to send my new motor to you. What are you charging for a "drag race" type mod? A private message is fine.
Z'Stein is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 Off



All times are GMT -7. It is currently 05:51 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net