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Old 05-25-2009, 07:35 PM
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piston swap

is there a way to change pistons to new rods at home. i have a good 1980 4 bolt 350 short block with stock pistons and 487 heads. im wanting to put some 11-1 domed pistons on the rods that are in the motor now to rais the compresion in order to run a bigger cam. figuring with the 75 cc chambers and domed pistons i may get a hotter street performance. thinking on getting a 30 30 cam. i may be on the wrong track though. any help?

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Old 05-25-2009, 08:29 PM
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Quote:
Originally Posted by doordude420
is there a way to change pistons to new rods at home. i have a good 1980 4 bolt 350 short block with stock pistons and 487 heads. im wanting to put some 11-1 domed pistons on the rods that are in the motor now to rais the compresion in order to run a bigger cam. figuring with the 75 cc chambers and domed pistons i may get a hotter street performance. thinking on getting a 30 30 cam. i may be on the wrong track though. any help?
Yes you can change the rods if you have the equipment. Some are press fit & some are floating pins. The floating is the easiest. If you have press fit, you will need to heat the rod pin area up with a torch and press the pin out with a hydraulic press. Getting them out is fairly easy but putting them back in is a little harder. You will need to heat the rod end up again and press the pin back in, making sure the pin is centered in the rod before it cools. Dome pistons are not the ideal way to raise compression on a street motor. You can run a thinner head gasket or have the heads milled or go with a smaller chamber head to bump up the compression.
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Old 05-25-2009, 08:32 PM
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If you have a press and a rod oven, yes. Otherwise, take them to someone who has the right tools. Doesn't cost much and the chance of something getting screwed up is much less.
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Old 05-25-2009, 08:46 PM
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Agree with 61Bone, just have a shop do it. It is real easy to ruin a piston pressing them on or off. If you want to press the old ones off and don't care about their condition, then you could remove them yourself with a press.

Do Not heat for removal as this will just make things tighter in the piston, heat is for JUST the rod eye at assembly. Pay a shop to do this as it is easy for a novice to mess this up.

There are hundreds of newer and better performing solid cams than the antiquated 30-30 grind that was designed in 1960.
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Old 05-25-2009, 08:50 PM
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Consider the piston swap cost vs head swap. If yours is a short block (assembled?) and you could sell your heads for a decent dollar you could apply the proceeds towards new heads with a smaller and perhaps more efficient chamber design, even up the runner and valve size. Domes are okay if that's your only choice or you don't want to give up your current heads. A flat top would be my choice with a head change to a smaller chamber.
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Old 05-26-2009, 11:25 AM
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Quote:
Originally Posted by doordude420
is there a way to change pistons to new rods at home. i have a good 1980 4 bolt 350 short block with stock pistons and 487 heads. im wanting to put some 11-1 domed pistons on the rods that are in the motor now to rais the compresion in order to run a bigger cam. figuring with the 75 cc chambers and domed pistons i may get a hotter street performance. thinking on getting a 30 30 cam. i may be on the wrong track though. any help?
The 487s are obsolete thinking in head design and a 30-30 cam is way obsolete in cam design and certainly isn't compatible with todays fuels.

Domed pistons get in the way of the burn and 11 to 1 won't work with unleaded fuel. Fastburn heads an example of which is the Vortec will pick up 40 or more hp over 487s. They need to be matched with either flat top or a D dish piston to hold the compression around 9.5 with an iron head or 10.5 with an aluminum head. This maximizes squish/quench to minimze detonation while extracting max power and efficiency.

The 30-30 cam looks like it has lots of duration, but most of it is ramps, you can see this when you do an intensity calculation of lift against duration. Compared to modern cams it's pretty weak. You can accomplish a lot more with a Comp Xtreme Energy or a Lunati Voodoo with way smaller total numbers in the duration column.

I'd strap on a set of Vortecs, or an aftermarket equivalent, first and see if that makes me happy before anything else.


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Old 05-26-2009, 11:54 AM
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Quote:
Originally Posted by ericnova72
Agree with 61Bone, just have a shop do it. It is real easy to ruin a piston pressing them on or off. If you want to press the old ones off and don't care about their condition, then you could remove them yourself with a press.

Do Not heat for removal as this will just make things tighter in the piston, heat is for JUST the rod eye at assembly. Pay a shop to do this as it is easy for a novice to mess this up.
Yup, it's easy to mess things up if you don't have the right tools etc on the press but this is the way I press mine. If you support the piston around the pin boss area and let the pin go through the support, the pistion will usually end up being fine if you are wanting to save them. mic the piston before and after so see if any chance took place. Also, I don't heat my rods with a torch on assemble. Too easy to end up with a spot getting too hot. A rod heater is best but use one that's automatic and won't turn the rod cherry red. I made a jig that uses a heat lamp. It takes more time to heat them up but it works.
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