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Considerations on pistons in a 360 engine. #424051 07/30/09 04:25 PM 07/30/09 04:25 PM
Joined: May 2005 Posts: 41 Denmark, Aeroe M Moparbil OP member
Moparbil OP member M Joined: May 2005 Posts: 41 Denmark, Aeroe	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

Re: Considerations on pistons in a 360 engine. [Re: Moparbil] #424052 07/30/09 04:35 PM 07/30/09 04:35 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	You're down to the bare block so definitely bore/hone it for plasma moly file fit rings, KB pistons to get the CR in the 10's w .040" quench live every 24 hour block of time like it's your last day on earth

Re: Considerations on pistons in a 360 engine. [Re: RapidRobert] #424053 07/30/09 04:39 PM 07/30/09 04:39 PM
Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN R Rug_Trucker I Live Here
Rug_Trucker I Live Here R Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN	Quote: You're down to the bare block so definitely bore/hone it for plasma moly file fit rings, KB pistons to get the CR in the 10's w .040" quench That much compression in a streeter? "The only thing to do for triumph of evil is for good men to do nothing" "NUNQUAM NON PARATUS!"

Re: Considerations on pistons in a 360 engine. [Re: Rug_Trucker] #424054 07/30/09 04:54 PM 07/30/09 04:54 PM
Joined: Jan 2003 Posts: 21,073 Niles , Ohio T therocks oh wait.but hey.lets see.oh yeah.
therocks oh wait.but hey.lets see.oh yeah. T Joined: Jan 2003 Posts: 21,073 Niles , Ohio	We have the KBs in my kids 360.They work well with 10.2 compression.Rocky Chrysler Firepower

Re: Considerations on pistons in a 360 engine. [Re: therocks] #424055 07/30/09 06:08 PM 07/30/09 06:08 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	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

Re: Considerations on pistons in a 360 engine. [Re: Crizila] #424056 07/30/09 06:59 PM 07/30/09 06:59 PM
Joined: Jan 2003 Posts: 4,588 St. John's Newfoundland 440newport master
440newport master Joined: Jan 2003 Posts: 4,588 St. John's Newfoundland	Is there a ridge at the top of cylinders? If not, I wouldn't be afraid to run new pistons without boring the block, just give it a light hone and go. I did my 360 this way. I prefer SpeedPro/TRW H116CP pistons over the KB's. At spec they're about 0.016 in the hole and give about 9.25 compression with stock heads. I had my heads decked about 0.020 to get 69cc chambers and about 9.66 compression. If there is a big ridge though, I would go ahead and bore the motor.

Re: Considerations on pistons in a 360 engine. [Re: 440newport] #424057 07/30/09 07:14 PM 07/30/09 07:14 PM
Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN R Rug_Trucker I Live Here
Rug_Trucker I Live Here R Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN	Quote: Is there a ridge at the top of cylinders? If not, I wouldn't be afraid to run new pistons without boring the block, just give it a light hone and go. I did my 360 this way. I prefer SpeedPro/TRW H116CP pistons over the KB's. At spec they're about 0.016 in the hole and give about 9.25 compression with stock heads. I had my heads decked about 0.020 to get 69cc chambers and about 9.66 compression. If there is a big ridge though, I would go ahead and bore the motor. Sometimes a ridge is nothing more than a ring of carbon. I've cleaned them with a brass wire wheel on a drill. I would mike the bores and check for taper before making piston decisions. And on a home/hone and build? Cast iron rings. "The only thing to do for triumph of evil is for good men to do nothing" "NUNQUAM NON PARATUS!"

Re: Considerations on pistons in a 360 engine. [Re: Crizila] #424058 07/30/09 08:17 PM 07/30/09 08:17 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova Banned. Forever.
69L78Nova Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	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)

Re: Considerations on pistons in a 360 engine. [Re: 69L78Nova] #424059 07/30/09 08:58 PM 07/30/09 08:58 PM
Joined: Aug 2006 Posts: 1,609 Southern Cal Noblewk top fuel
Noblewk top fuel Joined: Aug 2006 Posts: 1,609 Southern Cal	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.

Re: Considerations on pistons in a 360 engine. [Re: therocks] #424060 07/31/09 01:02 AM 07/31/09 01:02 AM
Joined: Feb 2005 Posts: 5,221 Branson, Mo. J joedust451 super gas
joedust451 super gas J Joined: Feb 2005 Posts: 5,221 Branson, Mo.	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. 75 Duster, 451 10.87 @ 123.58 NA 97 Z28 6sp., 12.01 @ 115 on a 100 shot 71 Swinger. 360 magnum. 12.58 @ 105 78 cutlass, 469 BBC. 12.70 @ 108 on street tires. http://www.youtube.com/watch?v=Z2kqNmMfheU

Re: Considerations on pistons in a 360 engine. [Re: Moparbil] #424061 07/31/09 03:27 AM 07/31/09 03:27 AM
Joined: May 2005 Posts: 41 Denmark, Aeroe M Moparbil OP member
Moparbil OP member M Joined: May 2005 Posts: 41 Denmark, Aeroe	The motor has the original dish type pistons and have never been touched. A quick check on taper, using the ring gab metode, shows a taper of 0,002 max. No edge is felt in the top of the cylinder using the nail test. Original honing marks are clearly seen in the lower part of the cylinder. Do not have correct tools to meassure cylinders on hand right now. If I can get away with only honing the cylinders and install new standard size pistons, I will do that. 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.

Re: Considerations on pistons in a 360 engine. [Re: Moparbil] #424062 07/31/09 04:14 AM 07/31/09 04:14 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	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. live every 24 hour block of time like it's your last day on earth

Re: Considerations on pistons in a 360 engine. [Re: RapidRobert] #424063 07/31/09 01:03 PM 07/31/09 01:03 PM
Joined: Jul 2003 Posts: 4,770 Holland MI Ottawa 2 2boltmain master
2boltmain master 2 Joined: Jul 2003 Posts: 4,770 Holland MI Ottawa	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.

Re: Considerations on pistons in a 360 engine. [Re: RapidRobert] #424064 07/31/09 02:12 PM 07/31/09 02:12 PM
Joined: Feb 2005 Posts: 5,221 Branson, Mo. J joedust451 super gas
joedust451 super gas J Joined: Feb 2005 Posts: 5,221 Branson, Mo.	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 75 Duster, 451 10.87 @ 123.58 NA 97 Z28 6sp., 12.01 @ 115 on a 100 shot 71 Swinger. 360 magnum. 12.58 @ 105 78 cutlass, 469 BBC. 12.70 @ 108 on street tires. http://www.youtube.com/watch?v=Z2kqNmMfheU

Re: Considerations on pistons in a 360 engine. [Re: joedust451] #424065 07/31/09 08:09 PM 07/31/09 08:09 PM
Joined: Aug 2006 Posts: 1,609 Southern Cal Noblewk top fuel
Noblewk top fuel Joined: Aug 2006 Posts: 1,609 Southern Cal	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.

Re: Considerations on pistons in a 360 engine. [Re: Moparbil] #424066 08/02/09 10:33 AM 08/02/09 10:33 AM
Joined: Mar 2003 Posts: 140 west Michigan 7 76dart member
76dart member 7 Joined: Mar 2003 Posts: 140 west Michigan	KB190s

Re: Considerations on pistons in a 360 engine. [Re: 76dart] #424067 08/03/09 03:40 AM 08/03/09 03:40 AM
Joined: May 2005 Posts: 41 Denmark, Aeroe M Moparbil OP member
Moparbil OP member M Joined: May 2005 Posts: 41 Denmark, Aeroe	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.

Re: Considerations on pistons in a 360 engine. [Re: Moparbil] #424068 08/03/09 06:23 AM 08/03/09 06:23 AM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	IMO - unless you are planning on the engine running 100,000+ miles standard cast rings will more than suffice and save a few bucks at the same time. It was not uncommon for the OEM type rings to run 100,000.

Re: Considerations on pistons in a 360 engine. [Re: Moparbil] #424069 08/03/09 08:23 AM 08/03/09 08:23 AM
Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN R Rug_Trucker I Live Here
Rug_Trucker I Live Here R Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN	Quote: 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. I have a offenhauser inlet + 650cmf cab and headers. Iron rings are best for home honing. I have a set that have gone 170K+ no oil burning. And one cylinder was pitted due to crunching up a valve and spitting it out the exhaust! "The only thing to do for triumph of evil is for good men to do nothing" "NUNQUAM NON PARATUS!"

Re: Considerations on pistons in a 360 engine. [Re: RapidRobert] #424070 08/03/09 08:02 PM 08/03/09 08:02 PM
Joined: May 2005 Posts: 41 Denmark, Aeroe M Moparbil OP member
Moparbil OP member M Joined: May 2005 Posts: 41 Denmark, Aeroe	I have checked up a litle on what "quench" is. There is something which is still not clear to me. How do you actually meassure the distance from the flat spot of the cyl.head to the piston flat spot with the head gasket compressed.?? (Cyl. head installed) Is there a factor of a compressed gasket to use. How will you be able to meassure a tolerance of 0,04, the flat spot in the head is actually not completely flat. As I understand it, pistons are supplied with a standard quench and according to that milling of cyl.head must take place to obtain the ideal 0.04 Or is it milling of the piston. Of course I will like to have the highest compression but absolutely without troubles on pump gas. I would like to avoid any milling. As I read it, it seems to me that KB 190 needs milling but KB 107 or TRW speed pro do not. Please correct me if I am all wrong.

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