I'm getting ready to order parts in a couple weeks. I'm seeing kits out there that include pistons. I've already got a set of dished pistons already on the rods. But the particular kit I found compared to other things I'm looking at, its almost like getting the pistons free, so I figured I'd aask
If I were running a 350 bored .060 over, with 76cc combustion chambers (I know, but they are what I have right now), would the flat top pistons give a big enough jump in compression to be worth the hassle/money of having the pistons put on the rods ??? (I don't have a press or a torch)

 

Yes, but one better would be a new set of rods. When you have the dish top pistons pressed off you run the risk of busting a piston no matter who does it. Also if your set up is balanced you will to have the pistons balanced to match. Flat tops will run a good bit better and would be worth the change.

 

You can get a decent set of new cast flattops for just $70/set, and you should do it. Throw those dished ones in the scrap pile.

 

i bought a 1 ton Arbor Press from northern tool for $70 which i imagine would do the job well, and you can pick up a torch for less than $25. than you will have the tools for future use. they would both come in handy if you plan on doing alot of work to your car in the future. if you bring the pistons to a machine shop plan on handing them $100 or so to do it when you could do it yourself and have the tools for next time. that is my opinion.

 

that sounds great... what about balancing though?

 

now you have me thinking... the torch for 25 dollars. I'm guessing that's a small propane dealie. I've got a couple of those. I thought I needed an oxyacetaline. As far ast the press... how about one of these http://www.harborfreight.com/cpi/cta...temnumber=4711

 

dont get me wrong my beater tools are harbor freight, but northern defintely lasts longer and i trust them more for jobs that could cause more harm than benefit.

my good tools are all snap on, but there is nothing wrong with beater tool but i would spend a little extra and get northern as opposed to pos harbor freight which is really a crapshoot.

as far as the balancing you would need to get that done anyways.

 

flat tops over dished any day, but one thing that i have heard through the years is the torch and press method is kind of risky. just for what it is worth to you, if you get the rods to hot you can warp the beam on the small end and will ccause a weak spot in the rod. i have asked my machine shop here in ohio how they do it and they said that you can seperate the rod/piston combo in a press but the pistons are normally junk after removal. they said as far as reassembly for safety reason you should heat the rod progressively with an electric element to avoid warping the rod.

don't know wether or not you have done this before but i would hate to see someone spend any amount of money and run into problems. so good luck.

 

just do it very carefully, avoid excess heat if you dont need it. if the piston doesnt fit well dont use it, just be careful and you will be fine. i have pressed rod bolts in without issue.

 

thanks superT:
I'm actually really nervous about the whole thing. I've never done rods that needed to be heated. Done hundreds of bike pistons with clips, but this is a WHOLE different ball game :\
might be safer to just stick with what I've got. What machine shop do you use? I've heard some good stuff about a place in cecil. I haven't actually talked with them personally yet.
Anyway, any good parts deals down there in paulding? I'm not too far away, up here in Bryan

 

I recommend you don't try this. Pressing off pins often requires the piston to be honed. Putting the pins in requires the right amount of heat and a jig set to stop at the right point. You'll more than likely wish you paid the $8 a rod (here anyway) the machine shop charges.

 

You can press the pins out with a press ok but I would not use a torch to heat a rod that I was going to run in my engine. A rod heater has a timer on it preset at the proper temp. and you set the piston in fixture so you dont press the pin in to far or not far enuff.

 

just wondering if the pistons that you are looking at are press pin only or if you have the floating option. the reason i ask is that this could be a good reason/time to talk yourself into a new set of rods which has been brought up in this thread because of the balance of the current rod/piston combo. i bring this up because, the floating pin is supposed to free up power and take stress off of the rotating assembly.

i have seen good bushed rods for under 300 bones that are stronger than stock, which in the end could give you more room to grow without messing with the bottom end.