Piston choices for 360

[gliderider06]

Hey all,
I was thinking of adding some more go fast goodies to my 360 over the winter and was considering a piston change from the factory dished pistons. All things being the same in the motor would you run the Badger b290 or the Sealed Power 405cp pistons. I already have a set of the badgers hung on rods.
I was planning on running an old erson .480 Hyd cam with 1.6 roller rockers. I may have the heads done with 2.02 valves also, but unsure of that since they only have less than 2000 miles on them since the motor was rebuilt last winter, with the 1.88" intakes.
your thoughts?

 

[70aarcuda]

Which piston has the larger Compression Height?....the SP 405CP is a low compression replacement piston...

I would look at the KB107 piston...

 

[OldmanRick]

I would look at the KB107 piston...

The easiest way to in my opinion...^^^^^^^... And make balancing the assembly part of your build.

Hard to comment on the cam choice, especially not knowing if you have a more performance oriented converter and what gear you have, or will use?

The standard .480" grind was done by just about every cam grinder back in the day. It was very popular for a modest street car, and had some sound with it as most were usually ground with a 230@.050 intake & on a 108* lsa. I know, I used a bunch of them...lol!

With that said, a modern fast lobe Lunati or Comp cam will run circles around it these days. And don't forget to watch you're lift with a 1.6 rocker on those heads, unless the guides have been touched up for that kind of lift?

 

[dragondan64]

is that .480 lift with 1.6 rockers or for stock 1.5 rockers? Little different with 1.6 ratio rockers. with advertised .480 lift with 1.6 ratio brings lift up to .512 duration will stay same

 

[gliderider06]

Ok, I have more questions to answer. I am getting a trans thay has beeb built very strongly with a B&m holeshot converter 10". The cam is the Erson 280-.480, on 108 cl. With 1.5 rockers. I thought about going to the 1.6 rockers to give me more lift without adding duration. I have in the car now a 3.55 SG rear. When I rebuilt the engine last winter I cut the heads .040" , 3 angle valve job, new springs and port matched the heads. The lower end is dish pistons, standard bore re ringed and bearings. It runs really good, but I just want more out of it especially since I am getting this really good trans and converter. I have no track anywhere near me, so primarily street fun. I have a limited budget so stroker or solid roller cams are out of the picture. I have to keeo the upgrades under $1, 000 or the bride will get upset.
Thanks!

 

[RustyRatRod]

Since it's a 4" bore, you can get any piston configuration you want. People have even run Chevy pistons in them before.

 

[rumblefish360]

Gliderider, the KB-107's are inexpensive slugs that will raise your ratio to 9.7-1 with a standard bore 360 & a .038 head gasket. You can use a .055 head gasket for a slight drop in ratio. IIRC, it drops it closer to 9.5-1, very pump gas friendly and even better with the said cam above.

This is the best way to achieve a little squeeze to help operate the cam effieciently.

The other way to gain some compression is to kill the heads down.

 

[moturbopar]

you can also use the h116cp pistons. The good thing about them is they are basically the same weight as the factory pistons. So you can most likely get away with installing them and not balance the rotating assembly. Still a good idea to balance though.
http://www.northernautoparts.com/pa...son_shopping&gclid=CIyEkMTx5sECFdGCfgod8VEA9g

 

[Hipo65]

X2 on the KB pistons,id also keep the 1.88 intakes aswell. Unless you planned to spin er up there a lot. The 1.88's will help low end on the street most definitely!

 

[rumblefish360]

The H116CP slugs are coated on the side skirts with a anti friction coating.
MoPar used these Pistons in there short block assemblies. I don't know about the create engines though. There recomended for use by MoPar.

The cost a little more but IMO, probably worth the expense.
There very close in piston height to the KB-107's. IIRC

This is the slug I would recomend to use. But EVERYBODY, screams about doing things on the cheap.

 

[mderoy340]

Ok, I have more questions to answer. I am getting a trans thay has beeb built very strongly with a B&m holeshot converter 10". The cam is the Erson 280-.480, on 108 cl. With 1.5 rockers. I thought about going to the 1.6 rockers to give me more lift without adding duration. I have in the car now a 3.55 SG rear. When I rebuilt the engine last winter I cut the heads .040" , 3 angle valve job, new springs and port matched the heads. The lower end is dish pistons, standard bore re ringed and bearings. It runs really good, but I just want more out of it especially since I am getting this really good trans and converter. I have no track anywhere near me, so primarily street fun. I have a limited budget so stroker or solid roller cams are out of the picture. I have to keeo the upgrades under $1, 000 or the bride will get upset.
Thanks!

You loose .010-.015 lift from the cam specs with the SB mopar lifter geometry. When you milled the heads did you CC the chamber? If you rebuild the motor shoot for a 8.3 dynamic CR. The package you have now with a good converter should run around 12.6 or 7 in the 1/4

 

[ir3333]

a local builder and Mopar specialist swears by the H116cp.

 

[jerry6]

I like the Mahle pistons , lighter , have graphl coating , they cost a bit more though .https://www.flatlanderracing.com/

 

[Tbone416]

Which piston has the larger Compression Height?....the SP 405CP is a low compression replacement piston...

I would look at the KB107 piston...

What he said!!!!!

 

[gliderider06]

So, with the SP 115cp pistons, heads that have been cut .040" using a .055" head gasket, should put me in the mid 9's for compression. With me using the Erson cam I have (being that I still go that route) should be a good strong runner. I still have thoughts on putting the 1.6 roller rockers on it to give me the added lift. will/is there any drawback to running the higher lift rockers IE.. pushrod binding in holes, pushrod geometry etc... or should I just go and run a Lunati Voodoo, .497/.513 hyd cam or continue to run what I have without the 1.6 rockers?
Thanks!

 

[rumblefish360]

The only draw back to running high ratio rockers is valve to piston clearances, which I highly doubt you'll have and the all ready having an aggressive high lift cam and trying to add to the quick lift rate and actual lift, of for which your no where near to being even remotely close to doing.

In other words, run the 1.6 rockers with the bigger & better cam.

 

[greenswinger]

I have KB 107's in my 360 with Mr. Gasket .038 head gaskets. You get a little more squeeze with the KB's versus the Sealed Power units. Just gap the rings per instructions if you go KB.