Those are some weird ring/piston measurements. Usually 5/64's rings in top and second.

JIM

 

I am glad I am not the only one baffled by this mess. Both the top and second rings are 5/64" (.0781 thick) as are new rings. However, new top and second rings are 0.190+/- wide (deep into the piston groove) as is the existing top ring, however the existing second ring is only 0.165 +/- wide in most places. The spacer must have been 0.025" thick prior to crumbling into the short pieces I removed.
I have a better 1/66 dated 275 hp / 327 under the bench which any intelligent man would stick in and set this original engine aside. However, I got caught up in the "retaining the original drivetrain 12/65 build" thing. Don't know why as the numbers don't make it run better.

Here are pictures of the head with one of the worse exhaust seats and a fairly new valve in that seat. I personally think the seats will grind out with a light hit on the 45 and 60 degree surfaces. My problem is the guide work.

Ron

Worn exhaust seat.

Fairly new valve in the worn valve seat. Not recessed. I am thinking it can be lightly ground and maintain the seal.

 

OK so ring "thickness" is correct...but the "width" is weird? Are the piston grooves the same depth?

2.02/1.6 valves will get you into good meat for the valve seat.

JIM

 

I have only seen the back cut rings used in Drag racing. I knew a team that back cut the rings to reduce tension. They were chasing the A Stock NHRA record at that time. They did use spacer stock behind the rings after back cutting. I have never seen it used in OEM applications.

In A stock the parts had to look stock if they were torn down after a record setting event so the fast cars had secret ways to cheat to gain a little speed.

They also had to make weigh ins and the car had to meet the factory weight requirements. Some teams moved the weight from the front tires to the rear tires creatively, I have seen rear bumpers or tail lights filled with lead after they removed weight off the front of the car.
Fun stuff to see. It all helps a car that ran maybe a 13.20 from the factory but runs 10.28 at 129 MPH today in the stock class.

 

Yes, the piston are stock, stock piston groove width and depth. The spacer is all broken up, but you can see it must have been a wafer type as the wear pattern on both sided is intermittent.
The 2.02 / 1.60 valves are an option, but the fly cut to un-shroud the intakes would be an un-necessary expense for a mouse motor used just for a cruiser. The 1.60 valves are a reasonable option and preferred over hardened seats.
Ron

 

Those were the days!! I began drag racing a stock new 71 Vega and ran a tenth off of the national record in stock class by simply plugging the vacuum solenoid hose to the distributor with a ball bearing to get full advance in all 4 gears. As soon as it was paid off, I then followed Grumpy and dropped the 327 out of my 64 El Camino in it and a 66 Nova 12 bolt. Then as the bug bit deeper, built a 350, a full tilt 302, another 350 along with subframe and Nash 4+1, etc. Had to run in gasser class and couldn't really compete until ET racing was started. 11s weren't that bad for a full bodied street car. My wife decided she wanted to play to, so I dropped the 350 out of the 71 and a Muncie in her 67 Camaro and off we went. Used an old DOOOGE school bus and trailer as a car hauler for both cars. We were broke every weekend after paying the toll for two cars, fuel, and burgers for the kids, had to sleep in the bus. Couldn't afford to play with the big boys, but put a little pain in their butt and even won a few times.
I envy guys like Jim, still playing the game.

 

Many shops use a Serdi machine that will do any necessary chamber sweeps and cut the seats and blend the bowl all at one time. I had some 2.19's put in some oval port big block heads and in one operation they were beautiful. Very minor cleanup down in the port which wouldn't be needed in a mild case anyway...but if you did it would take 10 minutes for both heads.

Something still weird about that ring setup. As mentioned, rings are usually modded radially to reduce tension....never seen OEM setup that way.

Y'all are talking about good 'ole fun days.

I took a former AHRA record holder, Super Chevy feature car and put it back on the street. '68 SS Nova. I used a 396/375 with an L-88 cam and a tunnel ram/660 Holley's. 4 speed and 5.38's (replaced the 5.86's. 14x32's on the rear.

Once I looked closer at the car, I found it had aluminum bolts on everything that had a bolt, weight boxes hidden in the cowl panel and back corners of each door ( found because one window wouldn't roll down all the way due to hitting the box), It had a pretty bad rattle sound from the rear. I found round 6" long lead bars with eye-bolts threaded into the ends to make a chain of them which were fed up into the frame rails up over the rear end and hidden behind the bumper. With an iron head big block it had 54% of the weight on the rear tires. As you can imagine it would hook anywhere on the back roads we raced on. The rear suspension was done by Don Hardy using the same stuff they used on the Pro Stock Pinto's he built. It was super stout leaf springs with no floaters along with some ladder bars running parallel with the leaves. I also discovered the forward floorpans were craftily modified to channel the subframe some and the radiator support was also sneakily modded to allow fenders etc to line up. This allowed the front end/body to be dropped very low over the tires while maintaining the ground clearance AHRA required for the subframe to the ground. It came with two sets of fenders....one heavily acid dipped.

As you can imagine...this was a killer street toy and I drove it to work literally every day!

Sorry for the digress.....

JIM

 

No apology needed. I wonder if this car was raced due to the modification to the rings and added spacers? It certainly isn't a race cam in it now, and all of the other engine and drivetrain components are stock Chevy. The history on the car is lost. Just a cruiser.

 

Jim I think the best cheater I saw set the NHRA A stock class record in a 70 Challenger 440 six pack car but he actually ran a Dodge 400 engine stroked to the 440 cubic inches with the front snout cut off and replaced with a 440 front snout, welded on to look like a 440 block.
The 400 was lighter than the 440 and RPMed a little faster. With the 440 face on the 400 block it looked stock but was not. Different bore and stroke and lighter. It did hold the class record in the early 1990's A stock automatic class. He never got caught doing that.
Racers always find loop holes in the rules that allow them to go faster.

I watched two Challenger 440 six pack cars go up against each other in the Division 7 NHRA races. Both cars were running around 10.35 quarter miles against all competition.

When they ran up against each other there is some rule that says it is OK to break your dial in if you run against an exact same car.
These two Challengers ran between 9.90 and 10.10 in the qurarter when they faced each other since they did not have to worry about the break out rules.
Shows they were both cheating and ran flat out trying to beat each other when the rules did not apply. It was fun to watch.

 

Amazing a tech guy didn’t pick up on the deck height difference, numbers pad difference and intake manifold difference between a B and RB Mopar. Inspector Clouseau on the job I guess.