Joe Randolph's stroker article in the most recent Corvette Restorer

[Duke W.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

I think "core shift" is overhyped as is "slanted" decks. It can happen, but is not common, and, of course, there is some tolerance on positioning the cores in the mold. Just the same, having the block sonic tested in the critical areas is a good idea, and I think .030" clearance is okay. Sufficient static clearance is required to maintain clearance due to thermal and stress issues. Chevrolet recommends minimum .035" quench clearance, but many engines have been assembled and successfully operated with a lot less, and in this application you have both piston thermal expansion and "rod stretch" due to the high tensile load on the rod at TDC of the exhaust stroke.

Joe, I don't think you stated how much material you actually removed, but it doesn't look like more than about .050". Can you give an estimate?

As far as "cheater motors" are concerned, I don't have any problem with them, and I don't think most members do. As mentioned by Joe two long time, highly respected NCRS members who have held high offices did "cheater motors", and they weren't excommunicated.

I'm not a big fan of resto-rod Corvettes, but since judging is based on appearance and operational characteristics and we don't have X-ray machines to inspect inside the engine and other parts of the car, any internal mods to improve performance, function, or durability are on the table IMO, and a lot of creative talent and work have gone into the the changes that Joe and Tom have described.

Duke

[Joe R.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

I think "core shift" is overhyped as is "slanted" decks. It can happen, but is not common. Just the same, having the block sonic tested in the critical areas is a good idea, and I think .030" clearance is okay. Sufficient static clearance is required to maintain clearance due to thermal and stress issues. Chevrolet recommends minimum .035" quench clearance, but many engines have been assembled and successfully operated with a lot less, and in this application you have both piston thermal expansion and "rod stretch" due to the high tensile load on the rod at TDC of the exhaust stroke.

Joe, I don't think you stated how much material you actually removed, but it doesn't look like more than about .050". Can you give an estimate?

As far as "cheater motors" are concerned, I don't have any problem with them, and I don't think most members do. As mentioned by Joe two long time, highly respected NCRS members who have held high offices did "cheater motors", and they weren't excommunicated.

I'm not a big fan of resto-rod Corvettes, but since judging is based on appearance and operational characteristics and we don't have MRI machines to inspect inside the engine and other parts of the car, any internal mods to improve performance, function, or durability are on the table IMO, and a lot of creative talent and work have gone into the the changes that Joe and Tom have described.

Duke

Hi Duke:

Unfortunately I do not know how much material I removed, because the '657 block already has a shallow notch and all I did was make it deeper. I do not have an unmodified '657 block to compare it to. I would guess that I removed about .100", since there was a small amount of interference before I started, and I was trying to achieve .050" clearance.

I'm glad to hear that you think the clearance can be less than .050". My rationale for thinking that .025" would be okay is similar to yours. Most performance engines are built with about .035" quench between the top of the piston and the head, and that seems to work fine. When you consider the extreme forces at work on the piston and rod as the piston crosses TDC at 6000 RPM, it is easy to imagine some amount of "rod stretch" and related flexing of the crank. Thermal expansion is also a factor.

Compared to what is happening as the piston crosses TDC, the situation when the rod bolt passes the clearance notch is a walk in the park. The piston is at an intermediate location in the bore and flexure of the rod along its long axis is not a factor.

I used this rationale to conclude that if .035" is okay for quench distance, .025" should be just fine for the the rod bolt notch in the block.

[Gene M.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Yes, I mentioned the 5-speed in the introduction part of the article. The only clue when looking at the cabin is the 5-speed pattern on an original-style insert. Of course, when you look underneath it's clear that it's not a Muncie. This is a full-deduct for the transmission in NCRS judging (25 points). You can also lose operations points because the Tremec does not have reverse lockout, although I managed to add a reverse lockout so I could pass the ops test for the Founders Award. My solution was not very pretty, but it worked.

While I love having a 5-speed and I would recommend it to anyone who does a lot driving, I don't think an article about the conversion would be a good candidate for the Restorer. I figure I have already stretched things a bit with the 383 article, but at least that article is about maintaining original appearance.

Joe,
Now that would be interesting setting up a reverse lock out. Being that a Muncie goes to the left and forward and a Tremic goes to the right and back that has to be a bit of handy work. All internal shift linkage would scare me.......!

[Joe R.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Joe,
Now that would be interesting setting up a reverse lock out. Being that a Muncie goes to the left and forward and a Tremic goes to the right and back that has to be a bit of handy work. All internal shift linkage would scare me.......!

Hi Gene:

The Tremec TKO600 has no external shift linkage. It just has a shift rod coming straight out the top of the case. For Corvette conversions, the vendors move the shifter location to the left so that it matches the Muncie's external shifter position, but the shifter remains just a rod sticking out of the modified case.

The reverse lockout that I fabricated for Founders Ops judging was a bolt-on plate that fits over the place where the shifter exits the housing, so no internal mods to the transmission were necessary. The plate simply blocks the shifter from going into the reverse position, unless a lockout pin is pulled using the standard Corvette T-bar.

The lockout arrangement was intended to be only temporary, but it's still on the car two years later. The only visible difference is that the shifter rod is now machined aluminum instead of nice, shiny chrome. Eventually I plan to switch back to the chrome shifter rod and live without a reverse lockout.

[Francis F.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Great stuff,I'm in Awe....
thank's
Francis

[Gene M.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Hi Gene:

The Tremec TKO600 has no external shift linkage. It just has a shift rod coming straight out the top of the case. For Corvette conversions, the vendors move the shifter location to the left so that it matches the Muncie's external shifter position, but the shifter remains just a rod sticking out of the modified case.

The reverse lockout that I fabricated for Founders Ops judging was a bolt-on plate that fits over the place where the shifter exits the housing, so no internal mods to the transmission were necessary. The plate simply blocks the shifter from going into the reverse position, unless a lockout pin is pulled using the standard Corvette T-bar.

The lockout arrangement was intended to be only temporary, but it's still on the car two years later. The only visible difference is that the shifter rod is now machined aluminum instead of nice, shiny chrome. Eventually I plan to switch back to the chrome shifter rod and live without a reverse lockout.

Joe,
Yes, I follow you on the Tremec converted to fit the Mid years. I have one in my 65. Great tranny. I just want to know how you got the lock out to work when a Muncie goes to the left and forward and a Tremic goes to the right and back for reverse. How did you get the lock out & reverse position changed so lock out works going into muncie reverse position?

I have a custom one piece polished 3/4" stainless shifter shaft to look like the original 3 speed. The 3 speed does not have a reverse lock out so the "kit" shifter shaft was all wrong for my car. Too tall also. I replaced the chrome shifter shaft, reverse handle, two piece adapter with the two bolts & nuts, with stainless shaft end milled & taped to mate with the 90 degree offset mount while the top is threaded for the ball.

[Joe R.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Joe,
Yes, I follow you on the Tremec converted to fit the Mid years. I have one in my 65. Great tranny. I just want to know how you got the lock out to work when a Muncie goes to the left and forward and a Tremic goes to the right and back for reverse. How did you get the lock out & reverse position changed so lock out works going into muncie reverse position?

I have a custom one piece polished 3/4" stainless shifter shaft to look like the original 3 speed. The 3 speed does not have a reverse lock out so the "kit" shifter shaft was all wrong for my car. Too tall also. I replaced the chrome shifter shaft, reverse handle, two piece adapter with the two bolts & nuts, with stainless shaft end milled & taped to mate with the 90 degree offset mount while the top is threaded for the ball.

Hi Gene:

I made no attempt to alter the Tremec shift pattern. I simply added a lockout function for the existing Tremec reverse location (right and back). I don't know whether that would bother a judge for regular ops testing, but I was doing Founders Ops. For Founders Ops the function just has to be there. It doesn't have to match the original configuration. The most common example cited is that for Founders Ops it's okay to have an aftermarket radio, as long as the radio works.

So, an aftermarket transmission is okay too. The problem I had was that "reverse lockout" was on the ops checklist, and I did not have a reverse lockout. So, I added the function to avoid losing the points during Founders Ops testing.

[Gene M.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Joe,
I guess I made more out of it than was necessary. I just assumed it had to operate the same way. I never considered that only the function was required regardless of how it operates. I learned something.

[Richard M.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

This thread began before I got my Restorer and was wondering what the heck it was all about. I got it the other night and finally got to check it out.

What a awesome article Joe! I learned very much from it. Thanks for doing all that work to write it for us. Superb.

I nearly 30 years of being a member and reading Restorer's, it's great to see articles like this for those of us who "deviate" a bit over to the "dark side" once in a while. This, and the upcoming new judging categories for modified cars are absolutely positively going to help the overall health of NCRS and all it represents. Having FUN with Corvettes.

Well Done !

Rich

[Tom P.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Richard,
What you have said is EXACTLY what I have strongly advocated for over 30yrs!!!! Of course, the "old guard" has strongly opposed ANYTHING other than those cars which strictly (or mostly) adhere to the established guidelines of the judging standards. Over the years, MANY people have been turned off and/or turned away from NCRS (I being one, but for some unknown reason I have continued to hang in there for 35+yrs), in spite of all the primadonnas. I'm now beginning to feel that I may have a few "friends" within NCRS. In my opinion, a Corvette is a Corvette is a Corvette!!!! Let's acknowledge ALLLLLLLLLLLL of them and bring them into the fold!

[Joe R.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Yes, frequently, and I seriously flog it at every opportunity.
https://www.youtube.com/watch?v=kGwXc_BK5XI

Tom,

Nice burnout!!! I bet you could smoke the tires for the whole quarter mile!

Joe

[Stuart F.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Joe;

I too enjoyed the article as well as the additional discussion about it in this thread. Being an old "cheater" from my drag racing days back in the late 50's and early 60's, this type subject is close to my heart. I specially enjoyed Tom's photos of his neat 56 (is that old Chevy in the background his V8 powered driver? I too had a 50 coupe with a 58 Fuelie in it).

I have been pondering what to do with my original "never been apart" L-76 engine in my 63. I have toyed with the idea of pulling it for storage and replacing it with a new 383 crate engine, but I continued to struggle with the thought of showing all the cosmetic differences. I was specially hung up on the PCV arrangement and valve cover differences, etc. Now, thanks to your article, I won't lose any more sleep over it.

Thanks again Joe.

Stu Fox

[Mike E.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Question, if someone was to build a "Cheater Motor" and it was known to the judges to be one because the owner fessed up, but on the outside it appeared like a totally stock 327 could there still be deductions made?

Mike

[Stuart F.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

OOPS! Guess the photo of Tom's old Chevy is in the thread about the Frisco meet. Sorry.

Stu Fox

[Joe R.]

Re: Joe Randolph's stroker article in the most recent Corvette Restorer

Question, if someone was to build a "Cheater Motor" and it was known to the judges to be one because the owner fessed up, but on the outside it appeared like a totally stock 327 could there still be deductions made?

Mike

Mike,

For flight judging the criteria is supposed to be appears to be typical factory production. So I don't see how a cheater motor affects that as long as all the mods are internal. For a PV, if say a roller cam is installed, I would think that would be a deduction since the engine probably does not sound stock.

Joe