So i just got off the phone with my machinist (tommy at TW automotive in rochester). I gave him a block thats been in my garage for a year+. I stripped it down and brought it over earlier this week. He cleaned it up and measured everything. There is pitting on the cylinder wall so it needs to be bored out. He is going to go 20 over and see if there is any pitting left, then go to 30-40 over if there is. He told me to see what I could do for piston prices and get back to him. Here is a list of what i came up with. Could you tell me which pistons you would choose for each 20 and 40 over? I’m not sure what direction to go, what kind of gains id be making from 20-40 over. Should I just man up and go 40 over since its all apart right now? Or save some money and go 20 over?
heres what ive found with prices:
20 over:
-wiseco 20 over with rings and moly coating 8.3:1- $375-400
-Top Line 20 over, no rings 9:0- $160
-Ross 20 over, with rings 9:1- $450
screw saving money, save Yourself some cylinder wall. If You can, go .020 over and have room to bore it again if needed later.
Although, I have no idea what kind of motor You’re using, nor what application. I assume boosted based on the compression… in which case, I reitterate, don’t make those walls thinner then You need to.
if i’m not mistaken Ross is made by JE or vice versa… i agree with Nikuk try to stay with the 20 over and out of those choices i like Ross the most. altho wiseco isn’t bad either, and that comp ratio would be nice for TONS of boost if thats what u have planned
for sure. he told me to see what i could do on 20, 30 and 40 over. hes going to go 20 over, check the bore, if its still bad go to 30 over and then to 40 over. THEN i order the pistons.
i was just asking for a suggestion on what CR and company to go with. the choices ive found for each company is listed above. this isnt about saving mney, i only put up the prices for comparison. im not rich by any means, but money isnt the deciding factor here.
At 40 over though, IF something does go wrong, don’t plan on using that block again. It’ll pretty much just be a very large paperweight at that point. You said on another site your goal wasn’t anymore then 300whp. That can be reached with 20.
Like everyone else wrote, see what your machinists ends up boring it to, then make your decision of which brand of pistons to go with. I’m assuming your block hasn’t been machined before, so you should be able to get away with a 20 bore, 30 at the most. If it has been machined, then the machinist might have to go 40.
he said that one of the walls was worse then the others, and that one would be the deciding factor on what the bore would have to be. hes cutting them tomorrow so ill update you guys on whats going on.
and do you really see a big power diffrence going from stock bore, to 20 over to 40 over? ive never really read anything about the gains from that. and at this point in time, if something goes wrong with this block down the road, oh well. i have atleast 1 more 7 bolt block and 1 more 6 bolt block. both would need a rebuild, but i have them none the less. im not worried about my engine turning into a paperweight.
on that note, would having it bored 20-40 over have any effect on the durability/ strength of the block?
Wiseco is an “OK” piston. Ross, JE, and Diamond are more top-end brands. I never used “Top Line”. As far as prices go, I assume you are comparing apples to apples? Similar designs, wrist pins, etc. I am much more familiar with OHV V-8’s and using the ubiquitous SBC and JE as an example, there are 10-12 distinct piston lines. The prices and application are different for each. Before ordering any of the brands you should call the manufacturer to be sure you are getting the correct piston unless you are absolutely sure of what you are ordering.
I agree that you should go 20 over if that is enough to clean up the bores.
no you will not see a noticeable power gain from stock to .020 or .040" over. For a boosted engine I would go for the thicker cylinder wall. If it cleans up with .020 then that is fine and stick with that. I would only use Topline pistons if you are looking for a complete stock rebuild.
As far as pistons I like using JE and Mahle they both make excellent 4G63 pistons
Ross, Arias, Wiseco, CP all make good pistons also
He speaks the truth Nick. Despite me joking with you on the phone, you want the most wall you can get with a boosted engine. You wont notice the difference anyway. What turbo are you putting on? How much boost do you wanna run? Those all play factors in what CR you should go with too. Plan EVERYTHING out.
