426 pistons in a .060" over 413 - WTF?!

[RustyRatRod]

The oil rings control oil, not the clearance. As long as oil ring tension is good, it won't use anymore oil than normal. ALL piston engines use a certain amount of oil to begin with. The rings simply minimize it. I actually prefer low tension rings....even on the street. You're not gonna see even a half quart loss from one oil change to another, yet the performance gain is worth it.

 

[Photon440]

Kind of hard to find out a lot, since TRW pistons aren't made any longer. The SpeedPro site, which took over TRW, mentions a minimum of .004 in a couple of places.

Some old TRW literature mentioned using .0015" per inch of bore.

 

[62 Dart Convertible]

Thanks so much for all the help and info guys - I now have something to go on. I won't have time to measure this today (f#$%&@g work...), but will tomorrow and update this.

Ring widths are 5/64 top, 5/64 second and 3/16 oil.

 

[62 Dart Convertible]

I got around to measuring pistons and piston to bore clearance. Average piston to bore clearance is 0.008" which going by the information you guys have given seems fine - certainly not too tight as I first thought.

I was planning to order all my parts from Summit (remember I'm in Australia..) and going to use sealed power moly top rings, ie -
http://www.summitracing.com/parts/slp-e-233k
Is this a good choice?
Though the bore is free of any deep scratches, I assume re-honing when installing new rings is mandatory too?

 

[Garys1969RR]

Yes hone your cyl walls, or have a machine shop do it. That allows the rings to mate to the cyl walls.

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Also, what is your piston to deck clearance? I like to see .015 to .020. Gives good squish/quench. Better performance.

 

[cdr]

DO NOT use a flat hone!!! use a ball hone,about 8 strokes.

 

[69Bee]

I got around to measuring pistons and piston to bore clearance. Average piston to bore clearance is 0.008" which going by the information you guys have given seems fine - certainly not too tight as I first thought.

I was planning to order all my parts from Summit (remember I'm in Australia..) and going to use sealed power moly top rings, ie -
http://www.summitracing.com/parts/slp-e-233k
Is this a good choice?
Though the bore is free of any deep scratches, I assume re-honing when installing new rings is mandatory too?

That is fine, or use the Hastings rings numbers I posted above. Hastings makes excellent rings also, and usually cost less too. As far as the bore, stay away from a three finger deglazer with stones. This is the fastest way to screw up the cylinders by tapering them.

Use this instead: http://www.aceindustrial.com.au/flexhonetools.html

http://www.enginehones.com/technical.html

I use a 320 grit here at the shop when someone only wants to replace the rings, and the good thing is that the cylinder geometry will not change. I give each hole about 40 strokes with WD-40, and make sure all of the glaze is gone. The cylinders should be a uniform dull grey with crosshatch.

I have a 239 Ford Flathead in the shop now, and someone used the "three fingers of death" on it. Now the bottom of the cylinder has 0.0045" clearance on the best hole, and the worst clearance at the top is 0.0230". Not so hot so. Needless to say, I will be overboring it.

 

[RustyRatRod]

Right just use a ball hone. All it will do is break the glaze and restore cross hatch. It essentially doesn't remove metal.

 

[Garys1969RR]

What cyl heads are you using? 516s?

 

[62 Dart Convertible]

What cyl heads are you using? 516s?

Heads are 324s.

I cant measure quench clearance atm, engine is completely in bits..... Will do when I re-assemble. If it isn't enough do you remove some piston?
Attached pic -

I would like to get block decked enough to clean it up too as it looks like it has never been done since new, but I'd hate to lift compression much more...

 

[kb67mopar]

Just a quick note. If your gauge says its capable of +/- .001 you cannot measure to .0025. Significant digits... you are only as accurate as your least accurate number/tool. In this case the best you can measure is to the nearest thousandth. so if you measured 4.2475 your measurement is 4.248 +/- .001. So your bore is actually 4.247 to 4.249. That's the best your measurement can tell you.

 

[Garys1969RR]

Those pistons are the L2184, specs out to 11 to 1 C/R. Need to determine the compression height for that piston, then can figure the deck clearance. Thats done by adding 1/2 the stroke (1.875"), rod length of 6.768", and C/H of say 2.067" . This all adds up to 10.710'. Factory spec on deck height is 10.725". Leaving deck clearance of .015" Thats just right. I wouldn't cut the piston tops any. Use a thicker gasket if you want to lower the C/R.

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If you want that motor to really run good, get a set of closed chamber heads like the 915 or 516. Install bigger valves 2.14 intake and 1.81 exhaust. Use a .020 head gasket. Then you get good quench. But prob will need higher octane fuel.

 

[383man]

I am looking in my 63 Dodge book at the Max Wedge eng specs. For the 426 Max Wedge it calls for piston to wall clearance of:

11 to 1 - .0035 to .0045
13.5 to 1 - .009 to .0010

You should be fine where your at. It might have some piston slap when cold but many of the Max Wedges did. Usually goes away as it warms up. Ron

 

[62 Dart Convertible]

Wow, thanks for all the info guys.

I am considering getting a 320 flex-hone, and for only about $50 - I like to DIY as much as possible..

Heads are stock 324 closed chambers. I'm not out for big performance increases, so I'm not going to modify them. I am keeping stock exhaust manifolds and stock dual quad, but am going with a Lunati Voodoo 268 hydraulic. Car is a cruiser and I'll just be happy if it runs well.

I dropped in the crank and slapped a piston/rod back in to measure deck clearance. It is around 0.030" below the deck face, and the crown of the piston is proud of the deck by around 0.020". I'm guessing I should be fine to take a smidge off the deck then without reducing deck clearance too low, yeah?!

I was planning on using the Fel-Pro head gaskets in the full kit. What options would you suggest for a thicker head gasket and how much would it likely lower my CR?

Also, WRT oil pump, should I go with a Melling Std volume and pressure, hi volume or high pressure considering stock motor?

Again, I really appreciate your help guys!

 

[RustyRatRod]

I dont think that's enough cam to allow it to run on pump gas. I could be wrong.

 

[62 Dart Convertible]

I dont think that's enough cam to allow it to run on pump gas. I could be wrong.

I was previously running on 95-98 octane and it ran OK. It certainly didn't run on 91!!

 

[Garys1969RR]

Not familiar with the 324 head. Can you post a picture of the combustion chamber? And you said dual quad stock intake manifold. Are the carbs in line or the cross ram set up? Taking .010" off the deck surface should not be a problem, but no more than that. Those head gaskets are prob .040 thick. I prefer the .020 thick steel shim type. Gives better squish.

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With 7 cc dome pistons, deck clearance of .020, 80cc heads, and .040 thick head gasket, your C/R is 10.9 to 1. A .020 thick head gasket will bump it to 11.5 to 1 as the pistons are rated at.

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I used a Melling hi volume oil pump on my 451 and it works fine. Provides 25% more volume than a stocker, which is nice on a hot day when going up a long hill. Keeps the oil pressure from dropping too much.

 

[62 Dart Convertible]

Not familiar with the 324 head. Can you post a picture of the combustion chamber? And you said dual quad stock intake manifold. Are the carbs in line or the cross ram set up? Taking .010" off the deck surface should not be a problem, but no more than that. Those head gaskets are prob .040 thick. I prefer the .020 thick steel shim type. Gives better squish.

- - - Updated - - -

With 7 cc dome pistons, deck clearance of .020, 80cc heads, and .040 thick head gasket, your C/R is 10.9 to 1. A .020 thick head gasket will bump it to 11.5 to 1 as the pistons are rated at.

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I used a Melling hi volume oil pump on my 451 and it works fine. Provides 25% more volume than a stocker, which is nice on a hot day when going up a long hill. Keeps the oil pressure from dropping too much.

Thanks Gary. Can't post a pic of heads as I dropped them off at machine shop. I will find more info about them and update thread tomorrow - it's real late here!

 

[62 Dart Convertible]

Hi All

Just an update of where I'm at with this engine.

This engine appears to have been rebuilt over 20 years ago as the Clevite 77 bearings were date stamped 1989. Apart from No 1 and No 5 main shells being installed upside down and several rod bolt knicks in the BE journals creating some extra bearing grooves, it looks like it was assembled by a real pro (??!!). Lucky it hasn't really done much mileage, as the bearings would not have survived daily driver duties for long.

I dropped block, crank and heads off at my machinists for some work a few days ago.

The heads already had bronze thin wall guides installed and they and the valves are still excellent. Hard seats were also previously fitted to the exhaust seats, but unfortunately most of them are cracked and will be replaced.
Anyways, other than that, it is just a clean, reface and 3 angle valve job to be done there.
Also it still had the factory original springs fitted whilst an MP solid cam was also fitted - I wonder if this is the reason it wouldn't rev?!

Block will be cleaned, decked and rehoned - I decided to let them hone it as the less I have to do, sooner it will be running.

Crank just needs a few knicks linished and a polish.

In a few days it will be back on my stand for the bit I enjoy most in car play - to assemble it properly and make it look pretty. :love4:

 

[RustyRatRod]

At least you found out about the cracked seats before they fell out. That wouldda sucked. Bad. Sounds like you're on the way. Keep us posted.