Block Honing

[SBillinson]

"in order to accurately “map” a cylinder bore in order to obtain a clear dimensional picture of how that bore is shaped from top to bottom, a special “PAT” gauge is used."

https://www.championbrands.com/wp-co...2010_42-48.pdf

[Larry Hill]

Thanks for sharing

[Alan Roehrich]

Originally Posted by Larry Hill

My thoughts differ slightly from a lot of folks. I will check an aftermarket block just as closely as I will an OEM block. The best surprise is no surprise.

I do not disagree with my friend the tall man.


What I should have said was that the new aftermarket stuff is usually, good enough that you can simply check for perpendicularity, and then your dimensions will quickly show if there's an error. Every dimension on the aftermarket block will almost certainly required being "kissed" or "dusted". Same with any other aftermarket component, save a camshaft, I know of few people than can do any "adjustment" required on a camshaft, even if they can find an error.

[Alan Roehrich]

Originally Posted by dragracerray

Alan what is a PAT gage?
Ray

Ray,
The original "PAT" gauge that I speak of was developed by Traco Engineering, a couple of decades back, when they were working with GM in the development of the LS based engine racing program. GM required assistance because they could not get the LS engines to "seal up" and stay sealed up. It turns out that the bores on the LS engines of the time were never truly round. Even in the production engines, when no problem was present. It "appeared" that they were round. On machines, and with gauges, they "measured" round. Well, it turns out a regular "Sunnen style" dial bore gauge doesn't actually measure roundness with any real accuracy. So the "PAT" gauge was developed. The new CNC hones followed shortly thereafter.

[Ralph A Powell]

How did we ever get by back in the day? Yesterday I dug out my my OLD BILL JENKINS SA DESIGN BOOK in the block section Jenkins shows how he hand hones an small block and what stones he uses. Don’t know how we ever got by?

[Alan Roehrich]

Originally Posted by Ralph A Powell

How did we ever get by back in the day? Yesterday I dug out my my OLD BILL JENKINS SA DESIGN BOOK in the block section Jenkins shows how he hand hones an small block and what stones he uses. Don’t know how we ever got by?

I had a pretty close relationship with Jere Stahl the last few years he was around, and as a result, a connection with Bill Jenkins (as in, Jere would tell me that he and Bill were talking about one of my engine programs, and a direction I went with my R&D, and "Bill said to tell you that he thought you were smarter than that" and laugh.) where he would pass along things that he thought that I should look at.


Bill sent me a message one night telling me that we should be using a new Sunnen CNC hone, and we should have individual diamond mandrels for each 0.010" in bore size. That was what they were doing with their engine programs.


Yeah, we've come a long way since he once told me to plumb two Holley blue GPH 110 pumps in series, with 10 gauge wiring, and 0.060" washers under each pressure relief spring in the pumps, because our C/MP popped in high gear. Fixed it, too.


Bill, much like WJ, was absolutely as hilarious as he was brilliant, once you go to know him. But he never hesitated to bust my chops if I screwed up. It was always funny to get "Bill's take on Alan's mistake" from Jere.

[Ralph A Powell]

I first met Stahl in early 62 when he had a Lenoard gas station in Romulus, Mi on the intersection of Northline rd and West Huron River Dr. He mounted my first set of Cassler slicks in the early fall of 62. It was at his station that I met Jenkins in the spring of 63 Jenkins had brought the 63 Z-11 for Jere to build him a set of equal length headers.