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Discussion Starter · #1 · (Edited)
drop in piston's yes or no? pro's and con's
 

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Ok lets see if we can find out what your trying to do? 1) You had some extra money and didn't know what to do with it? 2) You need pistons so you thought drop in pistons sounded like they would work good in case you later want to try some drop in cams? 3) You want more compression? 4) You like the idea of new pistons and didn't want to bore your cylinders? 5) You over heard some one mention them and you thought you would sound cool if you repeated it....ONLINE?
 

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Speed Freak
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tone unless your going bigger bore I'd stay with stock pistons, the JE's are 13.5:1 but you can easily achieve that with decking the cyl head... we actually have quite a bit or room to lower the deck on these motors so you can get some very good compression in her. The JE's advantages might be they are maybe slightly lighter or as light as the stock pistons....

I ran a 40 shot of nitrous on a stock piston motor for over a year or so and never had one problem, its all in the set up....

unless your going to upgrade to a 2 or 3mm pistons kit I'd stick with stock and deck the head
 

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I'm not a fan of drop in pistons for raising compression. They usually have a less refined "crown" inhibiting flame travel-not good. I have seen drop ins out weigh the stock slugs, the motor then wastes energy overcoming the increased inertia born of a heavier recipricating part. Occassionally they will have more material above the compression ring decreasing heat shedding properties. Compression (all other things being equal) will be more efficient in getting the wheel turning (torque) but will not neccessarily compliment high rpm horsepower. I will go out on a limb hear and say if its a street motor a slight bump in cr combined with a slightly better cam would really wake it up and for that street motor that has to live with the rigors of street riding, I'm using stock pistons with a thin head gasket or take the manufactoring variables out of the squish band by milling the cylinder deck. If its a dedicated 1/4 mile engine (without class engine mod restrictions) I suppose a little further with cam and cr would make it really get down the strip. And if it is the 1/4 mile engine you are thinking about then I would look into some .080" over, 14:1 Je's.......:cool:
 

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i'm not a fan of drop in pistons for raising compression. They usually have a less refined "crown" inhibiting flame travel-not good. I have seen drop ins out weigh the stock slugs, the motor then wastes energy overcoming the increased inertia born of a heavier recipricating part. Occassionally they will have more material above the compression ring decreasing heat shedding properties. Compression (all other things being equal) will be more efficient in getting the wheel turning (torque) but will not neccessarily compliment high rpm horsepower. I will go out on a limb hear and say if its a street motor a slight bump in cr combined with a slightly better cam would really wake it up and for that street motor that has to live with the rigors of street riding, i'm using stock pistons with a thin head gasket or take the manufactoring variables out of the squish band by milling the cylinder deck. If its a dedicated 1/4 mile engine (without class engine mod restrictions) i suppose a little further with cam and cr would make it really get down the strip. And if it is the 1/4 mile engine you are thinking about then i would look into some .080" over, 14:1 je's.......:cool:
:+1:
 

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Discussion Starter · #8 ·
Thanks guys for the info, I was asking because if i stay stock bore a guy told me he got some dropin's pistons cheep, there close to the price of the rings.
LOL i DONT just got money to give away thats why i ask for info thanks guy's for yall input.:thumbsup:
 

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Which size thinner head gasket is the best because they have different sizes ultimately affecting the squish band. I think the .50 or .45 probably would be the best ? What do you suggest Garth ?
 

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Speed Freak
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.45

we have plenty of room for piston to valve clearance... I havent measured squish but I've never had problems with that .45 in any motor and my current motor I'm decked .015" and I have the .45 (.008")
 

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I ordered the piston kit today, and a hone from Brush research. Can't wait. Going with the Thin Head gasket, Ti spring retainers and 105/105 on my cams.

I don't generally machine heads. I leave that meat there in case it ever needs a slight clean up.
I think you might have been able to skim the cylinder deck and use a thinner head gasket while retaining the original pistons, slightly fly cutting the pistons valve pockets if neccessary. There is also another little trick I have seen used that just might work for those liking stock pistons; angle mill the head surface taking more off the exhaust side of the head than you remove from the intake side. In this way you get the compression but may eliminate the need for piston fly cutting because the exhaust valves have smaller diameter and don't penetrate as deep into the combustion chamber (thru lesser exh lift numbers) as do the intakes. Lots of ways to skin a cat :idea:
 

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I think you might have been able to skim the cylinder deck and use a thinner head gasket while retaining the original pistons, slightly fly cutting the pistons valve pockets if neccessary. There is also another little trick I have seen used that just might work for those liking stock pistons; angle mill the head surface taking more off the exhaust side of the head than you remove from the intake side. In this way you get the compression but may eliminate the need for piston fly cutting because the exhaust valves have smaller diameter and don't penetrate as deep into the combustion chamber (thru lesser exh lift numbers) as do the intakes. Lots of ways to skin a cat :idea:
Hey I'm givin' you my best stuff here.......wth?
 

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I think you might have been able to skim the cylinder deck and use a thinner head gasket while retaining the original pistons, slightly fly cutting the pistons valve pockets if neccessary. There is also another little trick I have seen used that just might work for those liking stock pistons; angle mill the head surface taking more off the exhaust side of the head than you remove from the intake side. In this way you get the compression but may eliminate the need for piston fly cutting because the exhaust valves have smaller diameter and don't penetrate as deep into the combustion chamber (thru lesser exh lift numbers) as do the intakes. Lots of ways to skin a cat :idea:
:+1:
This is one of my squixer friends trick. I was meaning to ask garth if he has his head decked at an angle as opposed to just milling the head flat.
 
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