Stroker break in. Knocking

[Rotorwash350]

So I saved up my pennies and when I had enough I ordered a new kit.

I sent the block out to a different machine shop since my guy had died in the meantime. .060 over.

Block back. Assembled with new rods, pistons , bearings, pushrods, lifters and rockers. Arp bolts all the way around. New manifold and and exhaust.

40 kms in and it's started knocking hard while cold. Pulled the filter and full of metal.

I'm about at my wits end. I have about 8000 dollars and years into this project.

I'm pretty sure I'm going to crush this jeep with the excavator tomorrow.

[Cheromaniac]

I'm really sorry to hear your tale of woe. After sinking all that time and money into the stroker project, this is the last thing you need.
What engine oil did you use for the cam break in? Were there any additives? I think you'll soon find the problem when you pull the valve cover.

[Rotorwash350]

I used Lucas classic hot rod oil. I pulled the valve cover and thought I might find a loose rocker arm or something like that. Everything looks normal up there though.

Pulling the oil pan is next on my list. Maybe I can see the cam from below or if there's and scarring on the cylinders

[Rotorwash350]

Cylinders 12 56 I can get a look at. Looks like scraping on both sides of the walls of every Cylinders I can get a look at.

What would cause this recurring problem. Could it be a crank issue?

[Cheromaniac]

Which rods and pistons are you using?
If it's the IC944 pistons, the squared off balance pads on the small ends of the rods need to be rounded off to allow the pistons to rock fully in both directions. Otherwise when the engine warms up, they'll bind in the cylinders.

[Rotorwash350]

The first 2 attempts were with the stock rods and ic945 pistons. I inspected those after and there was no contact marks on the bottom of the pistons from the rod ends. This time it's Russ' custom rods and pistons. The block is already now 060 over. So I think that's it for this one . I have a pretty good collection of scrapped pistons now.

I managed to find the last junkyard block in 400 kms. I pulled it apart yesterday and it looks like its in good shape. 110 psi across all cylinders and the Crank and bores look really good.

Before I try again I need to figure out what is going wrong and I am out of ideas. This is the last engine around and I've already wasted so much time and money.

Any more ideas before I give up?

[optmaxx]

As a last resort, I'd have a professional builder put it together and break it in. I know that sounds lame, but you just seem to be having some bad luck.

Who put your pistons together, and are you using the correct sized pistons rings? Did you get the block cleaned before assembly? What kind of oil pump are you using?

[optmaxx]

When you say oil pressure was at 3 bars, do you mean that it was below 40 psi? Was it below the middle line?

[Rotorwash350]

3 bars is right in the middle of the gauge. New melling oil pump. Yes to all the all the other things. Everything was mic'ed and clearances were all right in the middle of spec. Machine shop did the pistons the first 2 times and I did them the 3rd time since these ones are wire locked. There is a small wear area at 2.5" depth from the deck , the circumference of the bore and on every bore where the damage seems to have started. With a mic it is .001 smaller than the rest of the bore. Testing each piston individually, they get a little tight at that spot. This was not the case during assembly.

[optmaxx]

Could be that the block was defective and somehow had an oil supply issue to the pistons that was undetected?

Do the 945s increase compression? Maybe the high compression was too much for the build to handle, and decking the block and head resurfacing will increase the compression. At least that's what I would start wondering, and think that maybe I should try pistons with lower compression. Running too lean can damage the pistons.

[Rotorwash350]

The block was not decked as it was still true. The head was true as well and just had a valve job done. So high compression should not have been an issue. .043 head gasket was used.

There was no damage to any of the bearings. No heat discoloration there. That would lead me to believe there was no oiling issues. Deformed block somehow? I just don't know how that would happen. Granted I never saw this block run before it was pulled.

[mornysern]

I had replaced the cam with a new comp cam that Russ put in a package for me. I read a bit on the dizzy gear being on backwards and tried to turn it 180 degrees to match the teeth but on both my dizzys the hole was slightly offset and the roll pin wouldn't allow for it. I ended up grinding an ear off and as I had read on some posts here and set it where it needed to be. It fired up instantly.

[CaptainBanana]

OK I'm years too late here but if you're struggling to get your dizzy or opda in the right position all you have to do is drop a flat screwdriver into the oil pump drive and rotate it a smidgen.

[Hellfrekke80]

It has the icon ic945-030 forged pistons. So the ring gap should be OK? I haven't had the time to pull it apart yet. Maybe I will get a chance tonight.