428 help please

[aarons428]

i have my motor out of my truck and have it 90% apart so far so good.

What arp rod bolts should i get?

[ScotiaFE]

If your going to change out the bolts then you should really
have the rods sized and re bushed.
Make sure you clean the pins before you knock them through the piston.
They get a ridge built up and it can score the piston pin hole.
Oven cleaner works great. Don't leave it on long though.
Use your piston pin when they size the bushing.
With stock 428 rods these are just fine.

http://www.summitracing.com/parts/ARP-155-6002/

[aarons428]

when should i check piston to deck hight? Before or after the rod recondition.

[jayb]

Before or after the rod recondition shouldn't matter; the rod length shouldn't change by any significant amount due to the reconditioning.

[bluef100fe]

I would check before you slide the pistons out so you could figure out where your compression was exactly. This will give you a baseline to make decisions on changes and will help to make guesses on how much the changes will help. I would measure cylinders 1-4-5-8 to get an idea of how much the block needs to be decked. The rod bolts are arp-155-6002 . Hope this helps

[aarons428]

Well i found out some BAD news today. I have a very bad gouge down one cylinder prolly from the piston pin. I will pull the rest if the motor down tomorrow to see what happened.

Now what do i do? I think it will need to be sleeved. I feel sick. I didnt want to spend this kind of money.

 

[machoneman]

Maybe, maybe not. I'd reserve judgement until your shop sees it as it may clean up with an overbore.

Oophs! I just went back to Page 1 and now see the bore is already +.030.

[jayb]

Well i found out some BAD news today. I have a very bad gouge down one cylinder prolly from the piston pin. I will pull the rest if the motor down tomorrow to see what happened.

Now what do i do? I think it will need to be sleeved. I feel sick. I didnt want to spend this kind of money.

 

If the block needs to be sleeved it probably won't be that expensive to just do one.  And don't be afraid of the sleeves; I've run a sleeved 428 since the early 1980s with absolutely no issues.

[aarons428]

Well i got the rest of my motor apart.

1 of the pistons 2in of the top ring is shattered and 2 more pistons the top ring is broke into many pieces. I am assuming it is because cheap parts that have been flogged for two many years.

Number 8 cylinder the piston pin retainer is missing and the pin has wore a good sized groove down the the cylinder wall which will need to be sleeved. How far can a 428 be bored safely. the other cylinders are scufffed a bit. I did find the majority of the pin retainer in the oil pan.

For some reason #1 and #8 rod bearings are trashed but the rest are fine? The second and third main bearings are showing some copper but the rest look brand new. Is this odd or normal.

I was hoping to get this motor back together for cheap but now it will take a couple of years to get it back up to snuff.

I am up for suggestions on the bottom end do i trust the stock or go forged bottom?

[ScotiaFE]

You did say you put the NOS to it.
That will beat a set of rings up and put some stress on the bearings.
If your going to spray your going to pay.
Stock cast pistons are not up to spray on a regular habit.
A sonic check will give you a good map and you can get a pretty good idea
of how much wall you have by measuring the distance between the bores and subtracting
half that from the bore spacing which is 4.63 inchs-the bore.
ie: 4.63-4.160=0.47/2=0.235-0.125(which is half the distance between the bores roughly)=0.110".
You will have to gauge your block to find the exact distance between the bores.
It's call a drill bit test.
Bottom line I sprayed a 40 over 428 block until I end up with what you have.
Busted pistons, broke ass rings and wallowed out bearings.
I plan on doing that to a 427 Genesis too.
Hope you you get it back running.

[machoneman]

On the broken rings, usually only a few things cause broken rings. Using heavy shots of nitrous can cause the top rings end-butt. Check to see if the top ring ends are shiny or polished, indicating butting due to insufficient end gap clearance. Most ring makers do advise btw opening up the top ring gap from the standard clearance when using gas.  'Course, even without butted rings, using gas as noted above can and often will break rings (and worse) all on its own!

Btw, I'd carefully inspect that piston and pin that lost the end clip. It's entirely likely that you lost the clip not due to poor assembly but a lean-out on that cylinder causing the pin to pound it out due to heavy detonation. If the rings lands on any of pistons have collapsed (rings won't spin in the land) one can bet it's solely due to a bad nitrous tuneup.