Considerations on pistons in a 360 engine.
#424051
07/30/09 04:25 PM
07/30/09 04:25 PM
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Joined: May 2005
Posts: 41 Denmark, Aeroe
Moparbil
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Denmark, Aeroe
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I have a 1976 360 engine. I am planing to prepair it for a swap with the damaged 340 in my Cuda. I have striped down the engine to check the condition. It looks quiet OK. Chrank and bearings is very fine. Cylinders shown very little wear. I would like to increase the performance so it will produce around 400HP. Shall I keep the the original pistons and just change the rings and do a honing of the cylinders ? Or should I change pistons to obtain higher compression. Is it at all, vice to install new pistons without reboring the cylinders ? What is the compression rate of the original pistons ? Will they work well with the 340 or edelbrock alu heads ? What cam shall I choose ? Have checked the internet for engine rebuild kit Any recommendations ? Many questions, Thanks to all answers
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Re: Considerations on pistons in a 360 engine.
[Re: Rug_Trucker]
#424054
07/30/09 04:54 PM
07/30/09 04:54 PM
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Joined: Jan 2003
Posts: 21,079 Niles , Ohio
therocks
oh wait.but hey.lets see.oh yeah.
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oh wait.but hey.lets see.oh yeah.
Joined: Jan 2003
Posts: 21,079
Niles , Ohio
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We have the KBs in my kids 360.They work well with 10.2 compression.Rocky
Chrysler Firepower
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Re: Considerations on pistons in a 360 engine.
[Re: therocks]
#424055
07/30/09 06:08 PM
07/30/09 06:08 PM
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Joined: Oct 2003
Posts: 7,506 Az
Crizila
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master
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Az
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Steel heads = 9.5, aluminum heads = 10.5. Thats rule of thumb, as cam choice can have a big effect. Good rule for street cam / operation though.
Fastest 300
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Re: Considerations on pistons in a 360 engine.
[Re: Crizila]
#424058
07/30/09 08:17 PM
07/30/09 08:17 PM
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Joined: Apr 2007
Posts: 2,327 Glendale, AZ
69L78Nova
Banned. Forever.
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Banned. Forever.
Joined: Apr 2007
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Glendale, AZ
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Quote:
Steel heads = 9.5, aluminum heads = 10.5. Thats rule of thumb, as cam choice can have a big effect. Good rule for street cam / operation though.
I would also factor in quench distance as well. Im running over 11 to 1 in my 360 with aluminum heads and pump gas. Granted I am running the MP509 cam (unfortunately), and that is probably bleeding off a lot of it. As Im sure you know, with todays head and piston designs, along with modern cam profiles, the old rule of compression ratio limits on the street should go out the window
1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser
1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)
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Re: Considerations on pistons in a 360 engine.
[Re: 69L78Nova]
#424059
07/30/09 08:58 PM
07/30/09 08:58 PM
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Joined: Aug 2006
Posts: 1,609 Southern Cal
Noblewk
top fuel
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top fuel
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Southern Cal
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As said before, check the bores with a mic looking a taper and Bore. If your within .002" of spec get a good set of speed pro hyper pistons, if your .004" in spec get a set of KB forged pistons and run them. Hyper and forged pistons grow with heat. Not only that .004 with forged pistons will take a 200 shot of NoS with no problems.
If your over .005 get it bored. Else you will end up with piston slap that will drive you crazy.
I have honed and reringed many engines with success with clean bores. You have to mic them out to be sure, your eyes will have a hard time detecting a taper or .005"
66 Dart GT, 402 11.18:109 Best
63 1/2 Galaxie 500XL 406 4Speed 13.20:103 Best
2000 Ram
2005 Durango Hemi.
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Re: Considerations on pistons in a 360 engine.
[Re: therocks]
#424060
07/31/09 01:02 AM
07/31/09 01:02 AM
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Joined: Feb 2005
Posts: 5,221 Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
We have the KBs in my kids 360.They work well with 10.2 compression.Rocky
+2, if these are the KBs i'm thinking they are, its been awhile sence i built my .060" 360, i think they were KB192s if my memory serves me, they were a quench dome pistom, my compression was 10.35.1, ran great on pump gas with the XE284H cam, RPM air-gap, 750dp, stock J heads, this was by far the best street SB i owned, it was a screamer, at 3700ft. alt., it ran 13.2s @ 104 in a full bodied 73 Swinger & 4.56 gears, that was on the limiter in all gears too (6000 chip), car was low 12s @ sea level easy, so these pistons will work on pump gas & iron heads.
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Re: Considerations on pistons in a 360 engine.
[Re: RapidRobert]
#424063
07/31/09 01:03 PM
07/31/09 01:03 PM
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Joined: Jul 2003
Posts: 4,782 Holland MI Ottawa
2boltmain
master
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master
Joined: Jul 2003
Posts: 4,782
Holland MI Ottawa
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Stock replacement pistons will all be smogger compression. If on a budget go with the KB107. they are under $200 a set from Scummit.
Keep old mopars alive.
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Re: Considerations on pistons in a 360 engine.
[Re: RapidRobert]
#424064
07/31/09 02:12 PM
07/31/09 02:12 PM
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Joined: Feb 2005
Posts: 5,221 Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
Quote:
On e-bay I have found rebuild kits from Falcon performance that include pistons and cam. Is it OK ? Or should I go for TWR or KB. I am not building a race engine, more a street preformer.
With .040 quench you will be able to run pump gas with a CR in the 10's and CR is the most important parameter(imo)in an engines power producing potential. The pistons in those kits will not have enough CH. You want your short block parts selection to be spot on w nothing left on the table that way any future additions(or changes) will only compliment your foundation.
These would be the pistons i'd get, the KB190s that i ran in mine, it has a .040 quench dome, they are 219.00, they come in standard, .020", .030", .040", .060", .070".
http://www.summitracing.com/parts/UEM-KB190-030/?image=large
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Re: Considerations on pistons in a 360 engine.
[Re: joedust451]
#424065
07/31/09 08:09 PM
07/31/09 08:09 PM
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Joined: Aug 2006
Posts: 1,609 Southern Cal
Noblewk
top fuel
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top fuel
Joined: Aug 2006
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Southern Cal
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Get some Speed Pro ZH116CP's they have the "sexy" DurOshield® coated piston skirt and CNC machined.
Great pistons for the prices, they are not as heavy as forged and will not require you to hone the extra .001 for the growth factor.
66 Dart GT, 402 11.18:109 Best
63 1/2 Galaxie 500XL 406 4Speed 13.20:103 Best
2000 Ram
2005 Durango Hemi.
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Re: Considerations on pistons in a 360 engine.
[Re: 76dart]
#424067
08/03/09 03:40 AM
08/03/09 03:40 AM
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Joined: May 2005
Posts: 41 Denmark, Aeroe
Moparbil
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Denmark, Aeroe
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Ok.Thanks for all replies so far . I have been recommened TRW speed-pro, KB 107 and KB 190. Trw speed pro seems a litle low in compression and KB 190 a litle high, they also require machining of heads. KB 107 seems to me to be the compromise, that can used with both the iron 340 heads and alu aftermarket heads, am I right? The low wear of my cylinders in mind, I judge from your replies that boring the cylindes is not necessary and use of moly rings are best when doing a home honing. What cam will the right match? (Again good street preformer, not race) I have a offenhauser inlet + 650cmf cab and headers.
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