Moparts

360 pistons ?

Posted By: calrobb2000

360 pistons ? - 09/17/21 01:49 AM

hi ,

what pistons for a 360 to make it 10-1 compression ?

thank you !
Posted By: sasquatch

Re: 360 pistons ? - 09/17/21 03:01 AM

With what chamber CC and gasket thickness? Todd
Posted By: calrobb2000

Re: 360 pistons ? - 09/17/21 04:24 AM


looking for prob 0 deck flat top with small valve relief .

stock heads so 73 cc milled to what ever i need maybe to 69 cc , will depend on pistons i use ?
Posted By: Cab_Burge

Re: 360 pistons ? - 09/17/21 05:24 AM

Originally Posted by calrobb2000
hi ,

what pistons for a 360 to make it 10-1 compression ?

thank you !
Custom for your motor scope up
Posted By: Cab_Burge

Re: 360 pistons ? - 09/17/21 05:25 AM

Originally Posted by calrobb2000

looking for prob 0 deck flat top with small valve relief .

stock heads so 73 cc milled to what ever i need maybe to 69 cc , will depend on pistons i use ?

What year 360 are you working on?
Posted By: MichaelF

Re: 360 pistons ? - 09/17/21 05:28 AM

forged, cast or hyper?

check out the KB107, gives you around 10:1 with 69cc head and 0.039" thick Gasket (assumed the engine is bored .030"). The IC741 should be similar, but is a forged piston.

Michael
Posted By: 80fbody

Re: 360 pistons ? - 09/17/21 11:11 AM

Speed Pro has/had a hyper piston (H116CP) that was much better than the KB. No issues with blowing the top of the ring land off. I ran some in a 360 for several years without issue.
Posted By: fastmark

Re: 360 pistons ? - 09/17/21 11:31 AM

I’m working on a 340 with a 360 scat crank in it right now. My 894 heads cc were 72 with a .052 gasket and a -.008 deck with the KB 107 hyper junk pistons. It blew the top of the piston off above the ring about 2” long. I’ll post pictures from my phone later. It was about 9.25 CR. The motor showed no signs of detonating and the ring gap was .036 with about .004 piston to wall clearance. I’ve got another post about it but have not updated it with my findings yet. The Hughes engine site list most small block combustion chambers at 63? Mine were not. Maybe they are working off magnum heads figures. I get blasted every time I comment on these pistons being junk with “ it was not built with the correct clearances” guys, but I refuse to use them on a build. Incidentally, I called THE leading Mopar guru in the world and he’s shares my opinion on them as well. Without mentioning his name, he referred to KB hyper junk pistons as “ f***ing junk made out of melted down beer cans” . So at least I stand in good company.

Attached picture C543E6EF-69AC-4FDC-97F0-5C7751D291CB.jpeg
Posted By: Diplomat360

Re: 360 pistons ? - 09/17/21 04:16 PM

I'm with 80fbody on this...was running these Speed Pro (H116CP) 0.020" over in my 360 for 8 summery-only seasons, so when the weather's nice, you bet the motor went through a bit of a "work out"!

Anyways, pulled the motor earlier this year, all pistons looked beautiful. No skirt wear, no issues with rings, no complaints. I ended up running a 10.6:1 static CR, fast advance curve on 91 pump gas (iron heads), pressed pins.

Pic doesn't tell you much, but take a look, they were clean coming out.

Attached picture H116CP_pistons.jpg
Posted By: Locomotion

Re: 360 pistons ? - 09/17/21 07:17 PM

I don't have the part #'s handy, but SRP and Icon have good forged flattops that will get "0" with some deck milling.
Posted By: calrobb2000

Re: 360 pistons ? - 09/18/21 03:44 AM


75 , from an rv prob 7.8 - 1 now
Posted By: toddinNH

Re: 360 pistons ? - 09/18/21 05:56 AM

If you want a good, fairly modern piston, I have attached a piece of the relevant page from the UEM/Icon catalog.

Attached picture Screenshot_20210918-015159.png
Posted By: Mopar Mitch

Re: 360 pistons ? - 09/22/21 03:10 PM

The Speed Pro pistons H116CP are superb pistons -- best quality and specs of all from different brands! I have a set (030) that is still new in the box... intending to sell .. because I decided to go to a stroker which uses different pistons.

I'm sending Cal a PM. I'll be posting these onto Moparts soon.

I'd like to get $250... plus shipping
Posted By: Mcode69

Re: 360 pistons ? - 09/28/21 07:50 AM

Originally Posted by fastmark
I’m working on a 340 with a 360 scat crank in it right now. My 894 heads cc were 72 with a .052 gasket and a -.008 deck with the KB 107 hyper junk pistons. It blew the top of the piston off above the ring about 2” long. I’ll post pictures from my phone later. It was about 9.25 CR. The motor showed no signs of detonating and the ring gap was .036 with about .004 piston to wall clearance. I’ve got another post about it but have not updated it with my findings yet. The Hughes engine site list most small block combustion chambers at 63? Mine were not. Maybe they are working off magnum heads figures. I get blasted every time I comment on these pistons being junk with “ it was not built with the correct clearances” guys, but I refuse to use them on a build. Incidentally, I called THE leading Mopar guru in the world and he’s shares my opinion on them as well. Without mentioning his name, he referred to KB hyper junk pistons as “ f***ing junk made out of melted down beer cans” . So at least I stand in good company.
Same here almost exactly.
Posted By: jwb123

Re: 360 pistons ? - 09/28/21 01:47 PM

If you can afford them forged pistons are always better. I can not argue with that. BUT I have been drag racing and building engines since 1974, and I have run across many so called guru's with strong opinions on brands of parts, I have learned to take many of these comments with a grain of salt. I can rattle off a ton of engines I built with cast hyper pistons that worked well. A personal race engine that ran 10's for 6 years with no issues, a blown SBC with a 671, in a mini-rod tractor that ran for several seasons, heck it blew head gaskets and never hurt the pistons.

I personally think for mild race and street strip applications the 4032 forged piston is what I go with. And this alloy basically is a forged hyper piston, as it has 12% silicone added. Silicone stabilizes the expansion of the piston, but the trade off is a more brittle piston. I think the majority of OEM engines now come with hyper style cast pistons, so the technology is proven, but as with all technology you have to use it as designed. Wrong clearances are just not a choice, especially when deciding what is a good or bad product.
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