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by ptuomov
Sun Feb 16, 2020 7:30 am
Forum: Engine Tech
Topic: Piston wrist pin length
Replies: 68
Views: 4169

Re: Piston wrist pin length

It’s not quite 10mm, the thinnest part of the crown is 6.7mm/0.264” which is still very thick.
by ptuomov
Sat Feb 15, 2020 3:21 pm
Forum: Engine Tech
Topic: Piston wrist pin length
Replies: 68
Views: 4169

Re: Piston wrist pin length

How thick is it in the center? I don’t have the numbers here on the ski slopes, but it’s really thick. We wanted both ring lands to be really tall, and that allowed the crown to be really thick even in the center. From memory, something like 10mm, but I may be misremembering that. The pin is short ...
by ptuomov
Sat Feb 15, 2020 11:05 am
Forum: Engine Tech
Topic: Piston wrist pin length
Replies: 68
Views: 4169

Re: Piston wrist pin length

Here:
5420845F-E4B0-4A3B-9E8D-9D8176012892.jpeg
10AC195F-4461-4955-A583-DC37F4320227.jpeg
AEC27DA5-ECC6-4C85-A85C-7FB93594F911.jpeg
05027747-8276-4F92-ABF8-249A9EB2BDFD.jpeg
369F4972-8D07-43C4-BEF7-7CAFFF685F11.jpeg
by ptuomov
Thu Feb 13, 2020 5:32 pm
Forum: Engine Tech
Topic: Piston wrist pin length
Replies: 68
Views: 4169

Re: Piston wrist pin length

What is the motor's intended use? Street car, 5.0L, 93 octane pump gas, twin turbo, 8000 rpm fuel cutoff, 78.9mm stroke, probably about 800 lbf-ft torque over a fairly broad power band. Putting Subaru pistons in a V-8? They didn’t end up being Subaru pistons but custom pistons from another 100mm fo...
by ptuomov
Thu Feb 13, 2020 11:13 am
Forum: Engine Tech
Topic: L29 Vortec 454 on a budget
Replies: 38
Views: 3548

Re: L29 Vortec 454 on a budget

I don’t know if this is relevant regarding the cam swap:

http://www.superchevy.com/how-to/engine ... e-cam-swap
by ptuomov
Thu Feb 13, 2020 8:14 am
Forum: Engine Tech
Topic: Piston wrist pin length
Replies: 68
Views: 4169

Re: Piston wrist pin length

I’m looking at Mahle 100mm Subaru pistons with 23mm diameter piston wrist pins. The bare piston weighs 406g. The wrist pin is about 57mm long. The gap between pin bosses (for the rod small end) is about 29.5mm. This leaves about 13.75mm (0.54”) of pin inside the piston per side when the pin is perf...
by ptuomov
Wed Feb 12, 2020 3:27 pm
Forum: Engine Tech
Topic: Piston wrist pin length
Replies: 68
Views: 4169

Re: Piston wrist pin length

Another picture of 1987 vs 2020:
093410C2-CEC8-439B-A51C-13D690BC3BF6.jpeg
by ptuomov
Mon Feb 10, 2020 1:48 pm
Forum: Engine Tech
Topic: Crank scraper maybe little too tight?
Replies: 10
Views: 669

Re: Crank scraper maybe little too tight?

That would be my guess too. From the marks, I'd say both end of the rods were sized. That isn't the part of the rod that's closest to a windage tray or scraper. That’s where the marks came from, so mystery is solved. Windage tray comment was just for fun, they obviously can’t touch the rod so high ...
by ptuomov
Sun Feb 09, 2020 8:59 pm
Forum: Engine Tech
Topic: Crank scraper maybe little too tight?
Replies: 10
Views: 669

Re: Crank scraper maybe little too tight?

Kevin Johnson wrote:
Sun Feb 09, 2020 8:25 pm
Trim back the drawer handles a little. Should be fine.
I think the scraper/windage tray sheets clear the big end, where the geometry is tighter.
by ptuomov
Sun Feb 09, 2020 8:57 pm
Forum: Engine Tech
Topic: Crank scraper maybe little too tight?
Replies: 10
Views: 669

Re: Crank scraper maybe little too tight?

Just to cover the bases did you have the rods resized lately? Yep, those were rebuilt. I don’t recall those marks after the rods were rebuilt, but that doesn’t mean anything. I think you will find all the rods have that rub mark. Plus your scraper is cut to clear the big end of the rod is it not? Y...
by ptuomov
Sun Feb 09, 2020 8:40 pm
Forum: Engine Tech
Topic: Crank scraper maybe little too tight?
Replies: 10
Views: 669

Re: Crank scraper maybe little too tight?

Dave Koehler wrote:
Sun Feb 09, 2020 8:37 pm
Just to cover the bases did you have the rods resized lately?
Yep, those were rebuilt. I don’t recall those marks after the rods were rebuilt, but that doesn’t mean anything.
by ptuomov
Sun Feb 09, 2020 8:18 pm
Forum: Engine Tech
Topic: Crank scraper maybe little too tight?
Replies: 10
Views: 669

Crank scraper maybe little too tight?

The windage trays maybe a little tight in this engine?
F6496C23-D7C0-4B45-910B-B11D8809EEEE.jpeg
by ptuomov
Sun Feb 09, 2020 8:59 am
Forum: Engine Tech
Topic: Just for fun: Unequal length headers on an I4 because noise
Replies: 13
Views: 774

Re: Just for fun: Unequal length headers on an I4 because noise

How pulses are combined in the header will change the sound, I predict.
by ptuomov
Thu Feb 06, 2020 3:35 pm
Forum: Engine Tech
Topic: Dyno result for the risky business Porsche
Replies: 115
Views: 21689

Re: Dyno result for the risky business Porsche

John’s video update on pistons:

by ptuomov
Wed Feb 05, 2020 2:18 pm
Forum: Engine Tech
Topic: SBC Connecting Rod Offset - Honda Rod Bearing Width
Replies: 12
Views: 510

Re: SBC Connecting Rod Offset - Honda Rod Bearing Width

Doesn’t the Mahle clevite bearing catalog pdf list the lengths of all their bearings? Thanks for the lead, it did check that PDF but maybe I missed that measurement. https://www.mahle-aftermarket.com/media/local-media-north-america/pdfs-&-thumbnails/catalogs-and-literature/engine-bearings/eb-40-16....