Old School TRW 429 Flat Top-to-460 Flat top Conversion UPDAT - 460 Ford Forum
Engine Tech Archive A collection of all posts from the old Network54 forum

User Tag List

LinkBack Thread Tools Search this Thread Display Modes
post #1 of 1 (permalink) Old 01-24-2006, 03:20 PM Thread Starter
Forum Contributor
chilly's Avatar
Join Date: Jan 2006
Posts: 1,204
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Old School TRW 429 Flat Top-to-460 Flat top Conversion UPDAT

Next Topic >> Return to Index

Old School TRW 429 Flat Top-to-460 Flat top Conversion UPDATE
January 10 2006 at 1:27 AM
No score for this post
Paul Kane (Login PaulKane)
from IP address


I recently took a deal on a set of Speed-Pro TRW L2366's. The primary reason for buying them was to perform an old school trick where the top of this 429 piston is turned down so as to work with a 460 crank. In other words, move the piston pin up (in effect) by way of cutting down the crown of the piston. This is an old school racer trick from the early days, when forged 460 flat tops were few and far between.

As most here know, putting the old TRW 429 flat top into a D1VE or later block will get zero deck at TDC simply by cutting down the top of the piston .100" (your D1VE & later block deck height may vary). But could this piston mod still be executed with the newer Speed-Pro version of the old TRW L2366? My concern was that the piston design may have been modified/updated by Speed-Pro and render this modification unwise, perhaps resulting in a piston crown that is way too thin, etc. I needed to know and set out to get this question answered.

My measurements gave me the answers I needed:

Crown thickness at it's thinnest point (dead center): ~.250"

This is nice, This means that if I chuck these baby's into a lathe and indicate them at the flat top, whacking .100" off will leave me with a .150" forged aluminum crown thickness. Certainly acceptable in most naturally aspirated (unblown, non-nitrous) builds.

Crown to top of #1 ring land: .375"

Again, sounds fine to me. After whacking the top of the 429 piston down .100", the top ring is still .275" below top of our new 460 piston.

Potential weight reduction: ~95 grams

This calculation is ballparked from the following: piston material removed from the top is about 24.75 cc's (less valve relief). This is approximately 69.5 grams (depending on type of aluminum). The supplied piston pin weighs 182 grams but if wee substitute a light, tool steel pin (157g), then we save another 25 grams. Grand total weight reduction: 95 grams.

At this point, I am comfortable that the mod may be performed with no ill effects AND I'll lighten the piston a whopping 95 grams in the process. Cool!

Then I weighed the piston. My god....(scroll down)



Holy cow! One thousand grams with the pin! I couldn't believe it and grabbed a 100g weight from the other side of the lab placed in on the digital scale (to check the scale). The scale was dead-on accurate.

This means that after reworking the pistons to a 460 flat top, I will have a 905 gram piston on my hands (assuming I spring for the lightend piston pins). By way of comparison, Probe, J&E, and Venolia all offer a 460 flat top that weighs about 807 grams with the included lightened pin (650g + 157g pin). In other words, today there are 460 flat top shelf pistons that are still 100 grams lighter right out of the box. So this old school modification is now officially just that: old school

Frankly, I don't mind reworking the 429 pistons...takes maybe an hour and a half...and I get some sort of relaxation from doing this kind of work. Can also claim I "did it myself." But after this rework and you end up with a 900 gram piston??? Is it worth it?

Perhaps so, given the right circumstances. And here's why: The new, state-of-the-art 460 flat top piston sets (complete) retail for about $650 (about $700 with tax). By way of comparison, I bought these brand new 429 pistons, rings, pins and locks on ebay for just $285 shipped to my door/grand total. Not a bad deal. And in the right combination and/or application, they ought to suit the build just fine (emphasis on proper applicaton.). Certainly not the best choice for a higher end engine, but still an option for a lesser build nonetheless.

Thought y'all'd like to know,



High Flow Dynamics

Performance Components for the 429/460 Engine Family


This message has been edited by PaulKane from IP address on Jan 10, 2006 1:45 AM
This message has been edited by PaulKane from IP address on Jan 10, 2006 1:32 AM

Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message

Author Reply
Dave Keane
(Login daxcobra) re 2366
No score for this post January 10 2006, 3:45 AM

Paul that's interesting, I have the same pistons sat here ready to go in my 429 with the heads you did for me,I have a newly reground 460 crank and wondered if it was worth the hassle for the extra cubes etc, I also have a set of forged 460 2404 which may be a better choice, oh why do I have so many options!! still thinking about a +60 4.5 stroker as well!! Dave

Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message

Gary Blair
(Login GB3351) Sorry wrong thread. n/m
No score for this post January 10 2006, 9:16 AM


This message has been edited by GB3351 from IP address on Jan 10, 2006 11:20 AM
chilly is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the 460 Ford Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

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


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

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

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

Advanced Search
Display Modes
Linear Mode Linear Mode

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