This site is not affiliated with AGCO Inc., Duluth GA., Allis-Chalmers Co., Milwaukee, WI., or any surviving or related corporate entity. All trademarks remain the property of their respective owners. All information presented herein should be considered the result of an un-moderated public forum with no responsibility for its accuracy or usability assumed by the users and sponsors of this site or any corporate entity. | ||||||
The Forum | Parts and Services | Unofficial Allis Store | Tractor Shows | Serial Numbers | History |
ap 46 pistons |
Post Reply |
Author | |
jvin44
Silver Level Joined: 04 Mar 2015 Location: Elsie, MI Points: 53 |
Post Options
Thanks(0)
Posted: 27 Mar 2017 at 8:40am |
Anyone know off hand hiw much to take off tops of ap46 pistons to put in a wd45 engine looking for around 11.5 to 1 compression
|
|
Sponsored Links | |
mattb
Orange Level Joined: 11 Jan 2011 Points: 348 |
Post Options
Thanks(0)
|
Im thinking we took .100 off the set I did in my friends tractor came out to 11.5 to one when I figured it. Havent ran a compression test on it yet.
|
|
Big Orange
Silver Level Joined: 11 Sep 2009 Points: 313 |
Post Options
Thanks(0)
|
.250 will get you about 10.3:1, that's as hi as I would go with stock cam, & very hi octane gas, at stock 30 degree spark timing, + hi output coil & electronic mod.
|
|
Big Orange
Silver Level Joined: 11 Sep 2009 Points: 313 |
Post Options
Thanks(0)
|
That's with Sp 46 M&W kit .
|
|
jvin44
Silver Level Joined: 04 Mar 2015 Location: Elsie, MI Points: 53 |
Post Options
Thanks(0)
|
If u take .250 off u mights well not use the pistons might as well use 45 pistons. So im not sure
|
|
DrAllis
Orange Level Access Joined: 12 Sep 2009 Points: 20528 |
Post Options
Thanks(0)
|
Look, there are a dozen different piston molds. What you want to do is remove the minimum amount from the piston top just so it doesn't hit the cylinder head. Assuming it has a POWER CRATER bowl design, make the piston top flush with the top of the sleeve and then the head gasket will give you about .060" running clearance. THE COMPRESSION WILL BE WHATEVER IT WILL BE DEPENDING ON THE BOWL VOLUME. Years ago, I removed .170" from the outer edge of the piston tops on a set of M&W SP46 pistons. It had 240 psi of cranking compression and ran well with 103 octane fuel. Ignition timing will probably be around 25 degree BTDC at full throttle, but dyno tuning is the best. Cold spark plugs like AC Delco 43's is what I always use.
|
|
Post Reply | |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |