HawkRod is doing the 2023 Hot Rod Power Tour!

[HawkRod]

Hawk, did you take any pictures of the piston skirts before you had them coated? I'm dying to know how those short skirts held up.

I did...

...but then I had some issue with my phone, and my pictures got all messed up and I lost some. I know I took pictures of the pistons after I cleaned them. I just looked and could not find the picture I took of them (I will continue to look and will post them if I find it).

If you look at some of the pictures I just posted yesterday, you will see some light vertical scoring in the bores of the block. The piston skirts had the same kind of wear pattern on them, especially on the bottom of the skirts where most of the force is applied. This is the primary reason we decided to coat them to help with the wear.

For others that may be wondering what this conversation is about:
As the stroke in an engine gets longer, the rod length has to get longer, since the rod vs. stroke length really should be 1.5:1 or greater. But the bore is only so long, especially in a short deck "B" block like a 383 and 400. With a longer rod, the only thing you can do is shorten the piston. This means that often the pin even has to move up into the ring area. Here are two random examples off the internet.

Compare this length and pin placement to a more regular piston.

A piston's length helps to keep it from twisting sideways in the bore. A longer stroke also puts more side force on the short pistons near the bottom of the bore. This creates additional wear and is a one of the cons of a big stroker engine. So in a stroker engine, the piston to (bore) wall clearances become more critical.

Checking this, and making sure everything was as dialed in as possible, is one of my primary reasons for pulling this well running engine apart. I wanted to make sure all this stuff was ideal.

 

[HawkRod]

So this week I got my engine honed and my rods balanced. Here are the details for those of you that want to read on...

We only honed perhaps .001" out of the cylinders. They actually had some taper and out of round in them, so that made taking such a small amount out tricky.
It also looks like the previous honing job was done without a torque plate. If you look at these pictures (one with my finger pointing and the other without), you will see a dark spot. You can also see dark spots in the adjacent cylinder too. This is a low spot that didn't get honed when we took .001" out of the bore. Notice this is right below the head bolt. So likely the last time it was honed the block did not have a torque plate, and so this spot was high without the torque plate and then gets pulled in with a head or torque plate. Most of the cylinders have a spot like this. Again, we are splitting hairs here and this is not ideal, but the car will run fine with it just like that. However, and in theory, if every horsepower counted, this will allow a tiny bit of blow by for a millisecond or so, reducing power.

Here is my father-in-law honing the block

I then turned my attention to the rods. First, I checked the for size. Crush is extremely important so they should be in spec. Spec is 2.5000" to 2.5005". 7 measured fine, and were about .0002" above the minimum (about perfect), but one rod was .0007" above minimum, or .0002" out of spec. Crap!
Here is a picture of me measuring a rod:

Then I needed to recondition rod 8 that was out of spec. First I cut the rod down a tiny bit to "close" the circle (no pictures of this). This then makes it a few thousands of an inch too small. Then I honed the rod until it too came into spec by about .0002". Now all the rods are the same!

Speaking of all the same, finally I balanced all the rods. Personally, I think this is a pain in the butt to do this job. You need to weigh the total rod weight...

...then weigh the small end of the rod...

All the totals and all the small (and by default, the big ends too) need to be the same weight. Of course, when I measured these, two were off by about 3 grams. Again, not really noticeable in a street engine, but I wanted to get them closer. So you use the lightest rod as your reference and make them all match that. Simply grind off metal and keep checking them.

The problem is, grinding off about 5 grams on the big end transfers and adds about a gram of weight on the small end - it's voodoo! Anyway, after several rounds of slowly sneaking up on it, I managed to get all the rods the same (i.e. within .5 gram on any end) and they are now ready.

Next week I hope to balance my pistons (haven't done that yet) and clean my block for assembly. Thanks for following along!

 

[FU64RY]

In 2015 I drove my 1970 Road Runner 5,800 miles across country (one way, then shipped it back). In 2022, I drove my 1973 Road Runner over 11,000 miles across country, both ways. I had so much fun doing those trips - hopefully you all enjoyed following along as I posted pictures during our tours!

View attachment 1415370

I always said if the Hot Rod Power Tour did a route East of the Mississippi I would sign up for it. Well, guess what? It is East of the Mississippi this year so I signed up to be a "Long Hauler", which means I will drive the entire tour. At the Power Tour there will be lots of nice cars, so I will need to break out the best and take my 1970 Limelight Road Runner for this trip.

Of course, the name is the Hot Rod Power Tour. My 1970 is sporting the "born with" stock 383 engine with 92,000 miles on it. It runs well, but is a bit tired. It simply WON'T do for the Power Tour!

A couple of years ago I bought a 500 cubic inch stroker based on a 400 block. This engine was originally built by our own @qkcuda but sold by the guy who bought his Barracuda. I put this stroker into my car for a short time, but decided to pull it to check tolerances, etc.

In this thread I will prep my 1970 Road Runner for the Power tour (mostly build the engine back up again), and then I will post pictures during our trip to this same thread (rather than separate the threads as before). Hope you all enjoy following along the "journey"!

(Mods: If this needs to move to a different forum please feel free to do so)

Barry going along?

 

[HawkRod]

Barry going along?

Of course. He is as nuts as I am!

 

[Nxcoupe]

Well, I did some more checking of the block and also checked some pistons. Unfortunately the news for each was not great and is adding to the work I have to do.

For those who don't want all the details: I have to deck my block and cut weight off my pistons. (Keep reading below if you like details.)

I checked to see how "square" the block is. The crank centerline defines the heart of the block. You want the deck surface to be the exact same distance from the crank centerline for every cylinder. If is it very different, you end up with different compression in different cylinders so the engine does not run as well. If the value is the same for all 8 cylinders, the block is "square". Less than .002" difference is fine.

For those that haven't seen this done, here is one way to do it:
There is a 2.000" metal bar that goes through your mains. To make the bar fit your mains, there are custom rings that are exactly 2.000" ID and the OD of your block mains. In this picture I am holding a ring for a 440 (the 383/400 rings on already in my block). One each goes in journal #1 and #5.
View attachment 1418728

Then you take a "T" gauge and measure from the deck of the block on one side (in the picture below I am measuring cylinder #7) down to the metal bar inserted in the step above. In this case, I didn't care about the actual distance - I just set the gauge to read zero. (By the way, the actual length turned out to be 9.968", so this means my reference point was .012" below the factory spec of 9.980" - so this block had been decked before).
View attachment 1418730

Then, without changing the gauge setup, I measured cylinder #1. It measured -.001", meaning is was .001" LESS distance to the bar than cylinder #7.
View attachment 1418731

This is actually a good measurement - a .001" difference is good. But then I measured the other side of the block (cylinders 2 & 8). Cylinder 8 measured -.002", and then cylinder 2 measured -.003".

So back to front both sides of my block differ in length by .001", but the even side cylinders bank is .002" less than the odd side. Not a killer, but not great either.
But then the surface finish tipped the scales. The block surface finish is quite rough. If you scrape your fingernails against the surface of the deck you can feel the ridges. This is not great for sealing. Today's technology (head gaskets) like the surface to be more smooth.
View attachment 1418729

Per se, none of these things are killers, but they are not great collectively - at least not as close as I'd like them. So to clean up the ridges and square up the block, I will deck the block about .005" below my reference point. (That means I will shave off .005" at cylinder #7 and .002" at cylinder #2.)
Bottom line is after decking the block will be smooth and square, but I was hoping not to have to spend the time to do this.

But the big surprise was my pistons. This engine had high end KB (now Icon) forged pistons. I had a few minutes and decided to weigh them to finish getting them ready for later assembly. Weighing each is simple - just plunk it on the scale:
View attachment 1418745

You want each one to be within a half gram of one another. Piston 1 is shown above at 503.5 grams. Great, then #2, #3, etc.
I was feeling really good until I got to piston #6. WTF?!?! It is 4.5 grams light!
View attachment 1418732

I expected better from these pistons, and I am disappointed in the large difference. Also, I would be happier if one or two pistons were heavy, then I might have to work on one or two pistons. But now I need to modify 7 pistons to decrease their weight so ALL weigh 499 grams.

CRAP!

Also, these are small and light already, so it won't be easy grinding out 4 grams or so out of each. So how do you do that?
Well, There are little tabs on the insides of the pistons. This is a key area where you can take some material out without sacrificing the strength of the pistons. There are 4 little tabs that can be ground on each piston. In the picture below I colored black in the approximate material shape to remove.
View attachment 1418734

I'll try to get this done next week, but the highest priority will be to deck the block.

You remove metal from the pins. You will have to mangle a piston to get that much aluminum weight out. Weigh all the pins and match the heaviest with the lightest piston. Then weigh the assemblies and lighten accordingly.

 

[HawkRod]

You remove metal from the pins. You will have to mangle a piston to get that much aluminum weight out. Weigh all the pins and match the heaviest with the lightest piston. Then weigh the assemblies and lighten accordingly.

Thanks. The little "tabs" on the pistons can be safely removed, but my guess is that will only equal maybe 2 grams. If I can't get enough weight out of a given piston, I will need to look at the pins. However, if at all possible, I want to avoid forcing special pins to go with pistons. Some future caretaker may not know to keep the pins segregated while the pistons and rods are all marked.

 

[Skytrooper]

Another “must read” Hawk Rod adventure!!!

 

[1969VAGTX]

Following along because I am hoping to take the GTX on this year's Tour. That assumes I put a stop to this rear main leak once and for all. Then she will be ready to go.

I hope to meet you @HawkRod out on the road somewhere.

 

[T2R9]

Oh god I would love to do this some day! Work keeps getting in the way dammit!

 

[1969VAGTX]

Oh god I would love to do this some day! Work keeps getting in the way dammit!

Skip work one day during the tour this year and cruise over to Columbia or Rockingham for the day.

 

[HawkRod]

Guys, sorry for the slow reply. I was upstate working at my father-in-law's shop...

Following along because I am hoping to take the GTX on this year's Tour. That assumes I put a stop to this rear main leak once and for all. Then she will be ready to go.

I hope to meet you @HawkRod out on the road somewhere.

It would be great to meet you on the tour. As usual, the ratio of Chevys and Fords to Mopars will likely be 10:1. Us Mopar guys need to stick together!

Get on that rear main seal leak!!!

When my engine had one, I pulled the engine and then carefully followed instructions on a billet rear main seal kit. That took care of the problem. It was a lot of work, but worth it to get the leak addressed.

Oh god I would love to do this some day! Work keeps getting in the way dammit!

Yeah, working for a living can be a pain the butt. I'm lucky now that I'm retired I can more easily do this kind of stuff, although I have to be careful with expenses since I am on a fixed income. But heck, see if you can swing the vacation and go for it - the tour will not likely be this close to you again in the near term future!

 

[HawkRod]

I spent a lot of time the last couple of days up at my father-in-law's shop working on some heads for a tractor engine. In this case, a pulling tractor engine that makes around 5,100 horsepower! Each custom head is made out of a solid piece of forged steel and weighs 108 pounds (there are 3, each that top 2 cylinders). No water jackets, just intake and exhaust ports with valves. Anyway, they had just cranked up the boost to 150 PSI (no, that's not a typo) and during a run in the finals, it twisted a solid 2" output shaft in half. That caused the engine to rev to near 7,500 RPM, and that caused mass mayhem as pistons and valves became just a bit too friendly. All exhaust valves were bent.
Some new valve guides and here I am honing them for clearance. In this case, they run about .0045" clearance. In a street car, that is worn out and SHOT! But in this thing, it needs the lubrication and clearance!

Anyway, I did at least get my pistons balanced for my 400 based stroker.
I had several pistons in the 503 gram range, but one at 499.00 grams. So I needed to lighten pistons to get there.

I started with a piston that I showed a picture of in an earlier post. I decided to grind off the area colored in black to see how much weight it took off.

This was just a quick and dirty task with a high speed grinder to get a feel for the weight. Here is what it looked like when done.

It turns out it only removed about 0.5 grams. So it was time for some more aggressive, but also controlled, work. The jig pictured below very securely holds a piston by the oil ring land. The pin rests against a metal stop so you can accurately reinstall pistons in the exact same orientation. The Bridgeport then can take off very controlled amounts. You must have a bit that cuts a radius into the piston; if you cut a sharp 90* angle, you will create a weak spot that may be prone to failure (this is why cranks, for example, have radiuses ground into the sides of the journals).
The picture below shows while I am machining off some material.

This was nice and controlled. The end result...

Ta-daa!!

Next I will work on balancing the entire reciprocating assembly. It should be close since this combination was run before, but you never know...

 

[Big bill]

Really good information thanks for posting.

 

[HawkRod]

So I didn't get a lot done last week, but I did finish weighing all my parts so I can balance the assembly. Here is my balance card:

Next week I will build the bobweights and put this on the balancing machine. It should be close since this was run before, although I have made minor changes to the pistons and rods.

I also drilled out the oil feed passages for mains #2 to #5 to increase oil flow to them.

Notice the second smaller drill bit sticking out of the #2 main. This is the angle you need to drill to get to the oil feed galley - NOT directly down to the cam journals!

 

[qkcuda]

Any plans to dyno this when done Hawk? Curious as to actual HP with the Eddie heads. Also which cam is going back in?

 

[69a100]

I always said if the Hot Rod Power Tour did a route East of the Mississippi I would sign up for it. Well, guess what? It is East of the Mississippi this year so I signed up to be a "Long Hauler", which means I will drive the entire tour.

So what happened last year when they went from Memphis to Atlanta?
I guess that was to far East for you?

 

[HawkRod]

Any plans to dyno this when done Hawk? Curious as to actual HP with the Eddie heads. Also which cam is going back in?

I would like to dyno it if I have time. Of course, that would be with a different distributor and carb than my 70 (I run FAST fuel injection on the 70), but that shouldn't matter much. The Power Tour is coming up in mid June, so I am rapidly running out of time. If I can reasonably do it, I will.

Your original cam is going back in it - the "tamer" cam is going into my buddy's 67 GTX.

So what happened last year when they went from Memphis to Atlanta?
I guess that was to far East for you?

What's with the snippy comment? I guess driving over 11,000 miles across country wasn't enough?

 

[69a100]

What's with the snippy comment? I guess driving over 11,000 miles across country wasn't enough?

No snippy comment! You said that if they ever did one East of the Mississippi, your in. Well? What happened last year? Sorry if you're butthurt!!

 

[HawkRod]

No snippy comment! You said that if they ever did one East of the Mississippi, your in. Well? What happened last year? Sorry if you're butthurt!!

Yup, typical of your type of input to threads...

Sigh. I planned and drove my 1973 Road Runner across country last year over a two month period. I haven't yet learned to be in two places at once.

If you want to be that pedantic about my Power Tour statement and it makes you feel all high and mighty to point out a technicality, then so be it. Congratulations, you caught me. I'm now done with this stupidity and have better things to do.

 

[Darter6]

Outstanding ! I always had a blast on the Power Tours. I did 9 long hauls between 1996-2007
The most fun I had in my Mopars. Keep up the good work,I will be following,but only in spirit.
Maybe the next one.