Sonic Test Results

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
jtb032295
Member
Member
Posts: 168
Joined: Mon Feb 16, 2015 8:08 pm

Sonic Test Results

Post by jtb032295 » Mon Oct 23, 2017 12:33 pm

Hey guys/gals, quick question... The sonic test results are attached for another street stock circle track engine I am involved with. The build will be ~13:1 CR with 3.75" stroke and finished to a 4.040 bore. The bores will still need about .020 taken out for cleanup. Probably around a true 500HP and 6500-6800 at the end of the straights. So... Build it? Or find another block? Stock blocks only in this class.


Measurements were done at the bottom, middle, and top of each bore indicated by "T, M, B" in the document.
block1cylinder.xls
Thanks!
You do not have the required permissions to view the files attached to this post.

PackardV8
Guru
Guru
Posts: 5039
Joined: Sun Jul 30, 2006 2:03 pm

Re: Sonic Test Results

Post by PackardV8 » Mon Oct 23, 2017 12:44 pm

The build will be . . . finished to a 4.040 bore. The bores will still need about .020 taken out for cleanup.
Just to be sure we're all interpreting the same data.

1. Are the measurements from a standard bore or a .040" bore?

2. Will the finished bore be .040" or .060"?
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering

jtb032295
Member
Member
Posts: 168
Joined: Mon Feb 16, 2015 8:08 pm

Re: Sonic Test Results

Post by jtb032295 » Mon Oct 23, 2017 12:53 pm

PackardV8 wrote:
Mon Oct 23, 2017 12:44 pm
The build will be . . . finished to a 4.040 bore. The bores will still need about .020 taken out for cleanup.
Just to be sure we're all interpreting the same data.

1. Are the measurements from a standard bore or a .040" bore?

2. Will the finished bore be .040" or .060"?
Sorry, as far as I can tell the bore is currently a very worn standard bore @ ~4.020". It may have been bored in it's previous life but it seems unlikely because of the excessive ridge at the top of the bores. Either way, the hope is that it will cleanup and be bored and finished to 4.040". I think the cylinder walls will certainly be too thin at .060" over...

PackardV8
Guru
Guru
Posts: 5039
Joined: Sun Jul 30, 2006 2:03 pm

Re: Sonic Test Results

Post by PackardV8 » Tue Oct 24, 2017 1:18 am

Joe can confirm this, but back in the day, before aftermarket blocks, the 385"s ran .040" over and made your 500 horsepower and lived a pretty long life at 6500.

But yes, a standard bore block will have better ring seal and make more horsepower. But then again, today's thin rings seal way better than the old 5/64" stuff and light pistons running in today's torque plate diamond honed bores are way better than most of what was back in the day
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering

Post Reply