Inline-four crankshaft

[Jack Gifford]

A long list of messed-up engine parts is cause to say "Yeah, I dodged a bullet"!
Apparently ever since a detonation issue on the engine dyno it's been running with four scuffed piston skirts (two of them cracked), one oil ring pinched in its land, center main bearing destroyed and main web & cap distorted, and all four sleeves have piston ring "signatures" in them.
The damage during that last run is extensive: Three cam followers destroyed and cam lobes scored, two bent valves, a valve seat rotated in #3 and another fell out on disassembly, and #4 chamber chewed up by a piece of the #3 valve seat- which took the scenic route through the blower manifold! I believe this mayhem was initiated by my lousy design of oil passages through the followers' pivot studs. Drilling the desired .052" holes full-length through the 1.2" long ARP studs was not possible, so I had drilled them larger for most of their length, leaving just .2" to drill to .052". But what I created were sludge traps! A number of them were clogged with babbitt material from the center main.
Repairs are underway but will continue through the winter.

[Jack Gifford]

Among items repaired so far is the cylinder head- it's ready for valve seat machining. I tried a different approach to installing 3 new manganese bronze valve seats. I've always disliked the huge force needed to press them in (.006" interference fit). I rigged up a water heater to circulate through the head to get it to 180 degrees F (seat bores expanded .003"). With the head on the mill table and with a new seat on a spindle adapter, I held dry ice pellets around the seat for a couple minutes- which shrunk the seat by about .002". Worked slick as could be!

[Jack Gifford]

In hopes of preventing any future movement, I pinned all eight seats in place. A single screw-in pin on the outboard side of each seat, so no worries about a pin ever getting into the cylinders. The pins only go part way into the seats.

[Stainless1]

Jack, does the pin go into a divot or through the seat and ground flush?

[Jack Gifford]

Pin ends go about .100" into drilled divots in seats.

[Jack Gifford]

Repairs are proceeding, nothing noteworthy to report. While awaiting outside work- block align-bore, camshaft repairs, etc.- I decided to improve one maintenance aspect. My choice to run drives to the pumps and magneto out through the rear of the valve cover prevented easy access to the valve train- requiring removal of the pumps & lines and the magneto to allow valve cover removal. So I machined off the top of the valve cover and made it bolt-on. Hopefully valvetrain inspection, lash adjustments, etc. will be much quicker.

[Jack Gifford]

This photo shows the rough/crude as-cast openings in the valve cover for plug tubes. Not good, since the oil scavenge pump is trying to evacuate the crankcase, and can draw air/dirt through the poor sealing of plug tube seals to the covers. So I put the head on the mill table to indicate on the plug centers, then assembled the OHC baseplate and valve cover onto it and machined true surfaces for the tube seals.

[Jack Gifford]

The block is finally back home, $1,400 later! The center main web was so beat up that it required fabrication of a sleeve to install before being able to align-bore the mains.

[Jack Gifford]

Progress being made, but...
Pistons won't arrive until July 12th, so the Maine Event isn't possible. Perhaps the Harvest Event...

[Gman]

Couldn?t figure out how to message this to you Jack so I?ll post it here

[Jack Gifford]

I pulled out that Dec'62 Hot Rod issue (from my complete 1948-2022 collection) to re-read Don Francisco's Bonneville coverage. I don't see any mention of Marckley's results that year?
Coincidentally, that issue had good coverage of Mickey's Top Eliminator finish at the '62 Indy Nationals with the hemi Pontiac, which I witnessed. His success was instrumental in launching my adventures with hemi Pontiacs, when I bought a pair of the heads and an aluminum block from him in 1985. I used the hemi V8 successfully in mini-rod pulling from 1986-1998 (about 40 event wins and a Vermont points championship). The hemi head that had been my spare was used to build my lakester engine (after converting it to DOHC).

[Jack Gifford]

... Perhaps the Harvest Event...

What a bummer... no Harvest Event this year. That leaves me only some possible dragstrip test runs this summer.

[Jack Gifford]

Pistons are here, but I doubt I'll even get any test runs this summer.

[Jack Gifford]

Shortblock assembly started. Piston/rods in place. But I have a question. Since it only got a .010" overbore, I planned to machine my 4.000" tapered ring compressor .010". Indicating on it to center it, I discovered that it was ~.020" out of round- approximately octagonal. It's never suffered damage; I don't know who made it- no name on it. Could the shape perhaps have been by design? Another one I have is perfectly round. Anyway- I bored .010" out of it's minor diameter and used it successfully. I'm just curious.

[manta22]

Shortblock assembly started. Piston/rods in place. But I have a question. Since it only got a .010" overbore, I planned to machine my 4.000" tapered ring compressor .010". Indicating on it to center it, I discovered that it was ~.020" out of round- approximately octagonal. It's never suffered damage; I don't know who made it- no name on it. Could the shape perhaps have been by design? Another one I have is perfectly round. Anyway- I bored .010" out of it's minor diameter and used it successfully. I'm just curious.

Jack, that out-of-round condition is exactly what I found when some Bozo machine shop bored a set of Corvair cylinders for me. They put in a lathe with a 4-jaw chuck and tightened it down HARD. It was clamped out of round!