| Slant Six Forum https://slantsix.org/forum/ |
|
| Looking for "off the shelf" pistons in the 3.5" range... https://slantsix.org/forum/viewtopic.php?t=68498 |
Page 1 of 1 |
| Author: | Jase [ Wed Jan 14, 2026 10:20 am ] |
| Post subject: | Looking for "off the shelf" pistons in the 3.5" range... |
And landed on this thread which seems to go dormant: https://www.slantsix.org/forum/viewtopic.php?t=55968 I would think that they would be in common use if it were something that was 'easy' and yet the piston seems to have some merit. It is 3.5" It has a compression hight that is actually taller than the stock slant piston, so the piston is closer to the top of the bore at TDC. And supposedly they can be flat top, although I have not found them in the piston catalog I was looking through last night.. Sounds like DKD took a wild ride in a slingshot dragster, and has not been on much since about the same time. Or the whole idea fizzled.. |
|
| Author: | Dart270 [ Wed Jan 14, 2026 10:29 am ] |
| Post subject: | Re: Looking for "off the shelf" pistons in the 3.5" range... |
Interesting. Can you post a piston catalog page that has all detailed specs for this piston? That would help with evaluating this. What kind of motor are you trying to build? High RPM, NA, boost, static CR, cheap, stock rods,.....? Best, Lou |
|
| Author: | Jase [ Thu Jan 15, 2026 11:18 am ] |
| Post subject: | Re: Looking for "off the shelf" pistons in the 3.5" range... |
https://uempistons.com/themes/UEM/image ... .20.20.pdf Page # 57... very top of the page piston. I Started becoming interested in a 3.5" piston after reading DD's article on "stroking" where he offset ground the connecting rod... and ended up with a 240 cubic inch version.. Tho I did not fully realize that 238 of that was in the overbore... and the offset crank grinding just added compression. At the moment I am just exploring ideas.. but I would like to build a truck engine. All torque, and enough head flow for it to carry up to 4500. Looking for ways to add displacement... Stock rods are fine, Probably stock replacement style parts are best, and 87 octane initially. I would like to spend $$ where it does the most good.. and produces the most torque between 1500-2500 for the money spent.. If I was buying pistons, then why not get the big ones... as it doesn't seem to really add that much more cost, IF getting pistons already... |
|
| Author: | kesteb [ Thu Jan 15, 2026 11:52 am ] |
| Post subject: | Re: Looking for "off the shelf" pistons in the 3.5" range... |
The Buick/Rover pistons need the wrist pin hole enlarged or the rods small end bushed. They raise the compression to around 11:1 with a the typical \6 castings. And are no longer available in the "high compression" configuration nor forged. At least according to Summit. |
|
| Author: | Dart270 [ Thu Jan 15, 2026 5:53 pm ] |
| Post subject: | Re: Looking for "off the shelf" pistons in the 3.5" range... |
If it's an NA truck engine, then I see no reason for forged pistons. The recess in the piston top gets you back down to around the same effective comp ht as a stock Slant piston. I would bush the rod instead of modifying the piston pin hole. Personally, I would just use a 3.46" Slant overbore piston - cheap and plentiful - and mill the head/block for the CR you want. Almost all of your gains will be in cylinder head porting. 5-8 more cu. in. will not amount to much more torque or HP. Sure I would offset grind for 2-4 more cubes. Cam choice will also be important and we can help with that (Oregon regrind). Lou |
|
| Page 1 of 1 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|