JB weld, flex seal or full rebuild ?

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Heywodja

Heywodja

The Heartbeat Stops Here
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This is a 20 year project due to work and other life gets in the way stuff..

When I assembled my engine back In 2000..I used some single valve springs for break in @ the direction of Hughes Engines. So following the first hour or so of run time I was called away to work. Never installed the proper springs. Engine idled well and had zero vibrations, revved like a sewing machine, internally balanced with hughes stage 3 heads and 3038al cam.

Car sat for a long time till 2017. When I picked up the project again and over the last year or so been battling a crappy running engine, I was checking obvious stuff, plugs, wires, fuel etc.. checked the pushrods and found bent intakes on #5 and #7.. I am running zero deck height kb107 pistons and iron heads with 62cc chambers, I think we figured about 10.8 compression more or less. My son and I were tearing down the 360 in the dart this evening and I think we found the cause of the crappy running engine.. cylinder 2 and cylinder 4 were fubar.. this engine to my knowledge had about 5 hours total on it.. I couldn’t figure what happened.

My son was 16 back when I built the engine, and I left the car to go to work out of state. When i saw the damage tonight and gave him my best WTF dad look, first thing he says.. “Me an Rob only raced it a few times at hot august nights and around town, can’t we just get a couple pistons?” I asked him how many was a few and he says about 3 months or so.. I could see he was pretty nervous, so I let him off the hook for the most part..

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Nice work. Yeah. Keep lettin him off the hook. That'll show him.
 
If they are hyperutectic's, the ring gap is critical or it will pinch the piston off at the ring lands like you have. Has something to do with the expansion rate of the pistons compared to a regular piston. They require larger ring gap.
 
yeah, my first thought is ring end gaps, too. Notice how the pistons broke at the weakest point of the piston crown.
As for the pushrods?/intake valves? being bent, it's much harder to say because it wasn't clear to me which items bent, maybe you can clarify.
 
I have the same set-up except aluminum heads. I didn't let my combo get as far as yours did; the ring gap spec in the KB catalog IMO is too tight, and the skirt clearance might be as well. But in your case Ima thinking you also have too much compression for iron heads and whatever gas you were running.
I can't see pre-ignition damage on the crowns tho, so not sure.
I took my engine apart and took the skirt clearance out to about .0035,Which is pretty baggy compared to the spec. and I installed some File-fit plasma Moly rings. I put the top rings in a lil baggy compared to the spec. I don't recall how baggy, but I don't think it hit more than .030
So yeah it rattles just a tiny bit on cold mornings, but she's dead quiet after a minute or two. I cranked up the minimum cooling temp to 205*F, to see if the pistons would stick, but they were fine so I left that stat in there;and that was that.
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My pistons are actually .005 up out of the holes and the Scr maths out to 10.95. With the .039 FellPros, I get .034Q, and with the same cam that you have, installed 4* advanced, plus the Eddies,the Ica comes to 64*, and so the Wallace calculator predicts ;
Static compression ratio of 10.95:1.
Ica of 64* @900ft elevation
Effective stroke is 2.79 inches.
Your dynamic compression ratio is 8.75:1 .
Your dynamic cranking pressure is 178.90 PSI. .................... 179
V/P (Volume to Pressure Index) is 154 ................................. 154
Which is pretty much spot on; I think I measured 177psi. With the all-in ignition timing delayed to 32/34 degrees at ~3400rpm, I can run 87E10 in this, always have, since 1999.
And the engine is no longer tight. I buzz that cam to 7000/7200 as often as I can, but with 3.55s and the 3.09 Commando low gear, first gear pegs 53 mph and the gear splitter takes 7200 out to 68 mph. So that's that!

Ok now your engine, if a true 10.8 Scr, would be running
Static compression ratio of 10.8:1.
Ica of 64* ,@180ft elevation
Effective stroke is 2.79 inches.
Your dynamic compression ratio is 8.64:1 .
Your dynamic cranking pressure is 179.71 PSI. ................. 180
V/P (Volume to Pressure Index) is 154 ............................... 154

Ok so 180 psi is supremely high for iron heads, and very few on FABO profess to run that much with iron heads. I have heard it said over and over that 165 is tops for best pumpgas of 91(R+M)/2 .. So by most accounts your engine should be rattling itself to death. But I just don't see it on the crowns. So it looks like you just need to open up the ring gaps a tad.
Well that and a new set of pistons,lol.

The bent pushrods pretty much have to be from lifter pump up, due to the single springs inability to control the valve train. You better get your valves checked; I bet there are a few bent ones in there. My guess is the pushrods are way too long


Edit for elevation
Static compression ratio of 10.8:1.
Ica of 64*@4800 elevation
Effective stroke is 2.79 inches.
Your dynamic compression ratio is 8.64:1 .
Your dynamic cranking pressure is 155.03 PSI................ 155
V/P (Volume to Pressure Index) is 133 .......................... 133
 
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We got into only one side today, funny part is no real visible damage otherwise, but I suppose once we tear it all down we will find more detail.. Heads were clean and no valve damage visible.
I might as well stroke it now.. cost per cubic inch is very affordable these days.
 
AJ I lived in Reno when I built the engine, 4800 feet altitude, now I am in Texas 180 feet above sea level.. so some changes are in order. I am going to use the trickflows and some different pistons like maybe the kb 362
 
That would do it, post #6 edited

I don't think you will be able to run those 62cc iron heads with a stroker at 180ft elevation, and with that 3038AL cam.
the compression would have to be down around 9.5,
 
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AJ/FormS said:
That would do it, post #6 edited

I don't think you will be able to run those 62cc iron heads with a stroker at 180ft elevation
Click to expand...

Going with 190 trickflows, not settled on a combo yet.. just kinda looking at some options..
 
If you run the KB hyper pistons, make SURE you have ample ring gap or you will have a repeat performance. They are fine pistons, but they need their ring gaps. I also agree to run a little more than spec. I always step up to the nitrous spec even though I don't run it. Better to be safe than sorry. Also, if any nitrous might be in the future, add more ring gap. It won't hurt a thing, but not enough........well, you already see what that does. Good luck with the stroker!
 
RustyRatRod said:
If you run the KB hyper pistons, make SURE you have ample ring gap or you will have a repeat performance. They are fine pistons, but they need their ring gaps. I also agree to run a little more than spec. I always step up to the nitrous spec even though I don't run it. Better to be safe than sorry. Also, if any nitrous might be in the future, add more ring gap. It won't hurt a thing, but not enough........well, you already see what that does. Good luck with the stroker!
Click to expand...

Agree w/ RRR, but why not go icon pistons while ur at it , very good piston for the $$$ . Trickflows would b my choice also ----------jmo
 
Heywodja said:
Going with 190 trickflows, not settled on a combo yet.. just kinda looking at some options..
Click to expand...
IF you use hypers again, gap the top rings .034. Extra doesn't hurt believe it or not, in fact with those pistons it could only help.
Especially if you're running as lean as you or your son did. Thanks for sharing and cant wait to read about the rebuild and new combo. Maybe a mild solid roller next time and some icon fhr pistons.
 
In line with the heading, "You can't glue it back together!" Sounds like Ole Dad needs to find a set of Icon forged stroker pistons under the tree courtesy of "Sonaclause".
 
I am thinking when we assembled we followed their ring gap specs to the t
 
Me too.
Then had to take it all apart again.
Whenever I would shut the car off, I had to wait 10 to 20 minutes before the starter would turn it over again. I thought it was a weak starter at first, but no,it wasn't.
I already knew something was up, cuz it liked a lotta throttle to idle at, and it ran hot at 60mph; but I blamed it on the 292/108 cam.... cuz I never had a cam that big before, and I was learning..
I bought those KBs because the hype said I could install them at .0015 to .0020 skirt clearance. I was so mad when the block came back at .0025. Now, 6months later, I was thinking I owed my builder an apology. But still thinking the pistons were locking up, I sent the block out for another .0005.. (and while I was at it, I shaved the decks another .005, which is what it took to clean up the previous shop's work). So now I'm thinking that the skirts are gonna be .0030....... but no, the new machine shop can't measure forchit, and the block comes back at .0035 skirt clearance. Yeah I checked My tools. Anyway water under the bridge Ima thinking. So I put it back together with the same rings, and don'tcha know it, it's still locking up.
Well, you know, I'm learning as I go, so 14hours later I got some new file-fit PlasmaMolys in there with something like 10% more gap and badaboom, end of all my problems. Oh, and as a bonus, my LD tester can hardly measure the leakage; so I'm liking those rings a lot. Time well spent.
So what I learned was; .0035 skirt is more than adequate, .0025 was probably ok, and .0015 the minimum spec mightabin ok afterall but I'll never know.
Also;the .0065 ring factor spec in the catalog, for me, was just too tight
The towing/nitrous spec of .008, like Rusty says, would work.
But I was learning, and since I was freshening the engine every winter anyway, I skated up the middle (about .029),and it worked out for me.
Another thing I learned is that filing rings, with a hand-cranked, clamped to the bench, ring-filer; is kindof an art, and takes more learning than I anticipated.And Another thing I learned here in Manitoba, is the three top-tier machineshops I used, seem to be OK with a 2 or 3 ten-thousands tolerance when honing, and 2 or 3 thou when decking, and if the line hone is crooked, and your rear mainseal starts leaking right on the engine stand, hey, it ain't their fault.
So it took me a good day to figure out which rods to put in which holes, and every hole had custom-gapped rings, the KB pistons, thankfully, were about bang-on, and a 383 ropeseal seems to be keeping the oil in the pan. My thumbs and my feet,were so sore.
 
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I am thinking of going with the stroker kit..forged crank, forged pistons and possibly a roller cam..I would like to be in the 460- 480 hp range. My car has 3.55 gears with 26 inch tires and a 3000 stall converter.. I want a real quick street car, btw my block is an early LA if that matters, and the car is a 72 swinger
 
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Heywodja said:
I am thinking when we assembled we followed their ring gap specs to the t
Click to expand...

Even so, with some nutcases behind the wheel that had no respect (no offense), those pistons got HOT, I bet. Hot enough to do what they did.......even with them being in spec.
 
RustyRatRod said:
Even so, with some nutcases behind the wheel that had no respect (no offense), those pistons got HOT, I bet. Hot enough to do what they did.......even with them being in spec
Click to expand...
I had a little 77 hornet with a 360 in it, he burned the rear tires to the cords, swapped them to the front and burned them too.. trust me he is out of my will when it comes to passing cars when it is my time to go..
 
Heywodja said:
I am thinking of going with the stroker kit..forged crank, forged pistons and possibly a roller cam..I would like to be in the 460- 480 hp range. My car has 3.55 gears with 26 inch tires and a 3000 stall converter.. I want a real quick street car, btw my block is an early LA if that matters, and the car is a 72 swinger
Click to expand...
With a 4" stroke, it'll be quick alright.
 
How much added expense (complication) is added by installing a roller cam in my build?
 
RustyRatRod said:
About a grand.
Click to expand...
Yep.
Springs, switch to 10 degree locks n retainers if solid roller. Price accordingly..180-300
Cam-300ish bucks
Roller lifters 300-1,000+
Crane coated steel gear for billet core 90.00

It can add up. I went through herbert cams and got a nice setup for less.
 
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