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View Full Version : rebuilding my l36 427,need piston advice


cwc
05-16-2013, 04:18 AM
well im going thru my 427 in my 67 impala,the original owner rebuilt in the late 80's using l2268 pistons and the original heads,just a tad bit too much compression! im lookin at the l2300f with .140 dome.im thinking this will get me back close to my original 10.25 to 1. will these work with my original closed chamber heads? ive thought of using keith blacks,as i just finished building a 66 396/325 and had issues with the speedpro repalcements hittin my heads

earntaz
05-16-2013, 02:41 PM
I am about to do the same -- let's see what the panel says. I have looked at hyper and forged pistons and both have their advantages. If the RPM is kept below 6500 I think hypers will do the job with less piston slap due to tighter tolerances -- also better oil control. Many new HP engines use the hyper pistons. Forged work well also -- best at higher RPM ranges.

I will be using a set of 063s (right at 100cc) with a lot of porting work.

So I'll stand by for the experts ...

The TAZ

earntaz
05-16-2013, 02:42 PM
I am about to do the same -- let's see what the panel says. I have looked at hyper and forged pistons and both have their advantages. If the RPM is kept below 6500 I think hypers will do the job with less piston slap due to tighter tolerances -- also better oil control. Many new HP engines use the hyper pistons. Forged work well also -- best at higher RPM ranges.

I will be using a set of 063s (right at 100cc) with a lot of porting work.

So I'll stand by for the experts ...

The TAZ

earntaz
05-16-2013, 02:42 PM
Geezzee -- sorry for the double post ...!@#$

Salvatore
05-16-2013, 03:20 PM
Jerry MacNeish had the same problem with a 1965 396 that he just built for his Impala. The stock OEM pistons hit the heads.

VintageMusclecar
05-16-2013, 04:03 PM
Assuming the following:

4.280 bore
3.76 stroke
98.4 c.c chamber (702 or 390 head castings)
16.8 c.c. dome (spec for L2300)
Piston .020 down in the hole (un-decked block)
.040" head gasket
Approx. 10.27-1 compression
Change the chamber volume to 101 c.c. (802 head castings)
Approx. 10.0-1 compression.

For a <span style="font-weight: bold"><span style="text-decoration: underline">stock or very mild performance rebuild</span></span>, cast or hypereutectics are fine. For anything you're going to lean on, I would recommend forgings.

If you would like any help or advice on selecting a piston, I'll be happy to help.

earntaz
05-16-2013, 04:56 PM
Have you any recommendations/experience as to brands of hyper and forged pistons ...

What about flat tappet hydro street cams ??

Thanks -- The TAZ

VintageMusclecar
05-16-2013, 05:12 PM
KB Hypereutectics are the only ones I would consider using.

For forgings, you can go with Speed Pro/Sealed Power, SRP, Ross, J&amp;E, the list goes on. Note that some forgings are more suited for race applications in regards to material and ring choice. The Sealed Power/Speed Pro's have been around forever, and there are a few well-known issues you need to watch for such as dome to chamber interference.

If you wanted to step up to a high quality street-type forging, I would recommend Autotec pistons. They are a little more money, but they offer several nice features &amp; options not offered on &quot;off the shelf&quot; components.

For a camshaft, I would need to know all the specifics of your build, and as I don't want to derail the OP's thread, please shoot me a PM or an email and we'll go from there.

Salvatore
05-16-2013, 06:10 PM
How about Wiseco, do like them Eric?

VintageMusclecar
05-16-2013, 06:59 PM
Very high quality pistons as well.

cwc
05-17-2013, 02:00 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: [email protected]</div><div class="ubbcode-body">Jerry MacNeish had the same problem with a 1965 396 that he just built for his Impala. The stock OEM pistons hit the heads. </div></div>my 396 had never been out of the car,66k original miles,still had its original shim head gaskets.when my machinist called federal-mogul they blamed it on the machine shop,when we told them it had never been apart,the tech guy laughed and said no way possible could it be that old and never rebuilt before!

cwc
05-17-2013, 03:23 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: earntaz</div><div class="ubbcode-body">Have you any recommendations/experience as to brands of hyper and forged pistons ...

What about flat tappet hydro street cams ??

Thanks -- The TAZ </div></div>
iam going with Howard camshaft CL120991-10.they recommended it,and it was pretty much the numbers i had in mind.its [email protected] with .533 lift. my car is a 67 impala,m20 and 3.73. hooker super comp headers with full exhaust,but im sticking with the original intake and carb.

Salvatore
05-17-2013, 01:38 PM
That should run really well. Good luck with it