Help identifying lyc

[Kmr320]

:louisiana: :louisiana: Need some help my friends. I’ve built and worked on a bunch of engines but this is definitely a bastard engine. It’s a part motor I bought. Here’s goes. Lol. Seems to be a narrow deck 320 case ,which is clearanced on the bottom to use a 360 crank. It’s definitely a 360 crank. It has what seems to be narrow deck 360 cylinders. Def. 5 1/8 bore. And 72967 4 ring pistons. Big tube sump. I know for a fact that Lacey Everett built this engine in the early 80s. And it hasn’t been apart till now. Oh yeah. Also o360 rods. Any ideas??? Thanks y’all. :louisiana:

 

[Gary S]

So what is the question?

 

[BobBrack]

So it sounds like it is what your saying it is. A narrow deck 320 case ground internally to clear a 360 crank and rods. Then 360 cylinders to top it off. Carburated makes it 180 h.p.

 

[Kmr320]

Thanks for the replies. I was thinking 180. But the pistons were throwing me off. I’ve never run across 4 ring pistons that weren’t the old gpu style with the fourth ring on the skirt. These have 3 comp. rings 1 oil. Also. I know the 360 has a longer stroke than a 320 but is the deck height the same??

 

[Slidin Gator]

And 72967 4 ring pistons.

Those pistons are used on high compression 320 and 360 motors. The 3rd compression ring supports higher compression.

As for deck height, I measure 9" port to stbd using my trusty tape measure and half drunk eye on both an O-540 and O-320. It sure seems like a lot of work to avoid buying an O-360 case to begin with?? 180 Hp sounds about right, but I thought this was a parts motor?

Page through this link and you will find those pistons used on higher compression 320 and 360 motors.

https://www.superiorairparts.com/fi...ent_Parts_-_Piston_Ring_Application_Chart.pdf

 

[Kmr320]

Yeah it’s a part motor. But it was complete. Like stainless headers to mags. I bought it for the crank n rods to stroke my 320. The case has me curious. If the deck height is the same why would someone clearance it? Unless it’s a 290d2 someone modified. But those r a helluva lot harder to find than a n/d 320. If I get time after work I’ll take pics of that case. Thanks y’all for the info. It’s appreciated!!!

Btw. The reason the motor was canned is because it ate a camshaft. The only time I’ve ever seen one crack a case long ways with the cam bearings.

 

[BobBrack]

The o360 crank weights are a larger diameter than the o320. That's what hits. Sometimes depending on the casting the big end of the rod will hit as well.

 

[Kmr320]

Ahhh. Ok I gotcha. Thanks for the info. I’ve been reading and talking to some buddies about stroking my 160. I hear they make wicked power but with anything like that you loose dependability. And my lil 320 is going on 5yrs old and a sweet runner. I don’t want to ruin it. Lol. Maybe some 10:0 to 1 pistons and big tube sump in the future. Thanks again.

 

[Gary S]

Maybe some 10:0 to 1 pistons and big tube sump in the future.

Now your on the right track.