I just got sealed power rod bearings 2500 RAA 10 and when I put the 2 halves together they measure under 2" like 1.080. Is that the right number for .010 under? I'm not at home to match them up.
There are new 30 over trw forged pistos with valve reliefs in the for sale section but they are not much less than these: http://www.buyracingparts.com/pisto...totec-forged-350-buick-dished-piston-kit.html
They have flat tops but Gary H said the pistons I have are close to flat tops and after the reliefs they could be close to the same cc's. I am trying to buy a cc tool to measure the pistons.
Sean that is the same place I was looking at the flat tops. Gary said the cc's in the pistons I have should be about the same as the flat tops with valve reliefs. I need a cc tool so if anyone has one they will part with let me know. I can buy valve relief cutters from Lindy Tool to put in a head and cut the pistons. Here is a pic of the cutters for the 455.
Just got my Summit CC tool! I measured the piston dish and got 11 CC'S. Those Flat tops say 4 CC'S so I emailed him and asked if that's was per each relief or 4 for both. I might 0 deck the block and use these.
Do you know the CC of your heads? If not find out before you mill the block. How far in the hole are the pistons?
They are in a average about .050. The heads are 1968's but haven't checked them yet. What are 68's usually around in cc's? Scott with the flat tops said both reliefs together are around 4-6 cc's depending on the depth. So if I have 11 now I might have 14 after cutting the pistons a little. So 10-15 cc's sounds like a lot to me. What do you think? I need a lot of compression to make this 350 run 10's in the 72 that will be gutted. I think with porting the heads and that intake you got it won't be a problem.
Come on Ron,you know what static compression means,its the compression that is figured out after doing all the measuring. Dynamic compression is the compression that is leftover from the cam's valve timing. Anyway,if you are shooting for 12:1 static compression, you might want to look into using copper head gaskets,the Fel-Pro sbb 350 head gaskets are only rated for around 10.5:1 max. Not sure what the .020" steel shim factory replacements sre rated for,might be worth a try? You need to measure those head chambers,with the 6cc pistons and the .020" head gaskets and 56cc head chambers you would be right at 12:1. If the chambers are smaller you might be able to use the 10cc pistons. Derek
Might need zero deck and small chambers to get 12 to 1 . Was looking at that the other day thinking about running E85.
Hey Derek I was running numbers with a 4 in stroke too. I think it was around 52 cc combustion chamber to get 12.
Can get over 12:1(around 12.64:1) with these http://www.buyracingparts.com/pisto...utotec-forged-350-buick-flat-top-pistons.html and a 4.00" stroke with 58cc chambers and a .020" thick head gasket and a zero deck. With a standard 3.850" stroke and a .030" overbore,those pistons would yield 12.15:1 compression,zero decked with a .020" thick head gasket and 58cc chambers. Derek
I never really talked static or dynamic until I got on this site. But Steve with those Auto tech pistons said he could make them any compression height. I have .060 over right now. Here is what he said. I do not have a picture of the flat top piston, but it is basically the same, but flat. Symmetrical valve notches of about 6CC. For bores over .030, I can do a .055 (3.855) to use a good ring pack with 1.5/1.5/2.5MM thickness. This combination would run you $679. If you want to do .060, I can do it, but the only ring pack available is 5/64,5/64, 3/16. This package would be $629 Both of those prices are for pistons, pins and rings. The pistons are made by Racetec in their Autotec product line. (http://racetecpistons.com/rt_history.htm) The rings would be from Hastings. Lead time on either one would be about 3 weeks. The thinner ring pack on the 3.855 bore size offers lower weight, reduced radial tension (drag) and probably 10-15 more HP. Please let me know if you would like to get something going. If you would prefer a different brand of piston for whatever reason, I am a master warehouse distributor with Racetec, CP Pistons, Ross, and Diamond. I would be happy to quote you on any piston you wish. Thank you, Scott Scott Brown Competition Components, LLC http://www.buyracingparts.com/ 616-499-6223
We've been through this before Ron,these pistons; http://www.summitracing.com/parts/uem-3159hc-1-5mm/overview/ have a 3.870" bore with 1.5mm,1.5mm.3.00mm rings that would need to be file fit with your 3.860" pistons and give you the extra HP you want from the rings. Tell Scott about the rings from these pistons,he'll probably be able to get them to sell to you as a piston and ring package. As long as you set your ring gaps,the rings that are sold with those pistons should work great. Derek
