My new 347

[Dono]

I think the short block has been cursed from day one. I agree that I don't want to make the power that necessitates going to a dart block. It just isn't necessary. That and setbacks like I'm having could be extremely expensive on a nice block. I do know the Dart block will give more horsepower with everything else being equal (no block flex as mentioned).

I had a look at my new oil pump today. Cleaned it, checked rotor to end cap clearance, oiled it up, and re-assembled. The clearances are all far tighter than the blueprinting how-to I posted above. The pump runs super smooth, so I don't see a reason to screw with it. I will take my old pump apart at some point for educational purposes.

Both rotors were exactly the same height (that I could measure), and rotor to end cap measured .002, far less than the .006 spec in the how-to. Here's some pics of the pump, also showing the differences between this one and the standard m68. This pump is a standard pressure/standard volume pump. Just a few upgrades, and I read that the tolerances are closer than the m68 (I'll check my old pump as I'm curious).

 

[vroomzoomboom]

It is insane how much a stock 302 block will flex under load.

my old 302 lived with no problems with around 9lbs of boost, and i beat on it. don will back me up on that, as well as a few people i know on the east coast. the stroker i have now is a stock block with stroker guts in it, and i beat on it worse then the 302 (and have overheated it......twice....whoops), once again, don has really seen how abusive i am with it, but i am not pushing as much boost with it....yet.
don has just had real bad luck. i mean REAL bad luck. he isnt doing anything wrong. he isnt skimping on parts. its just a big black cloud over it. i think i jinxed him even when we first stuffed the motor into it. sorry don

 

[Dono]

I could very well be guilty of going to the wrong machine shop over and over. We will see if the new one I'm using works out better. They are a performance shop, and I guess this motor falls in to that category even though I havn't exactly pushed it.

Whatever. We are on the right side of the dirt, and even when we do pass away we cant take anything with us. I'd sure like to get away from work and take a cheap holiday somewhere though Beach and beer. Cant beat that.

And, thanks for the vote of confidence Tim.

 

[vroomzoomboom]

And, thanks for the vote of confidence Tim.

joe and i were talking about this the other night when you told me what they found so far. we both were scratching our heads. and we both know joe is no dummy either.

 

[Josh P]

I agree that Don has done a quality build with very good parts. I'm not knocking it, putting it down in any way. It is a fact that the stock block will distort under high power levels. Some people get 600-800 out of a stock block for a long time and others have them let go at 450. I think that you probably had a bad experience with the machine shop.

 

[delexploder]

When you blueprint the oiling system you need to do the whole thing, the guy i worked for , an engine builder , dose everything , drills every oil passage , like the crank , he enlarges the ports then champhers them the polishes the crank, also he will tap the plug holes and use pipe plugs instead of the little press in ones , his built motors run around 80 psi oil pressure , and he modifies the top gallys so the top end dosent starve , and he includes certain oil filters like a k&n or ford racing because a normal one will pop, as far as making the block survive in a stroker app, he taps the freeze plug holes , btw they are really casting holes , they get screw in pipe plugs with locktite and then he upgrades the caps with studs and a girdle , now the studs are another story, he has all the holes enlarged and uses a stud that fits tight in the non threaded hole of the head , cap, intake ect , and he also takes the time to not only balance and blueprint everything but also champher polish and surface everything including rings and bearings, and then everything gets cleaned at least 5or6 times , he has in the 20 years ive known him never had a motor failure,

 

[4pointslow]

Dono, you have done amazing work on this truck.
I agree with Tim that you have just had bad luck. Maybe that engine block is cursed? lol.
With a new machine shop, and maybe a new block?, it might all just come together.
Wishing you all the success you deserve for all the hard work you have put into it.

 

[Dono]

Thanks 4point. I'll get to the machine shop and see where they are at with it this week.
Judging from what looks like serious piston slap on the cylinders, I'm betting its either new pistons or new block. I'm betting that the cheapest route will be another block. Those Wiseco forged units are not cheap. There is also no way I could have done anything wrong that would have caused this. Something happened at the machining level somewhere along the line.

 

[4pointslow]

There are two things I can think of that would cause too much piston to cylinder wall clearance.
One is overheating, the pistons swell up (expansion) and get scuffed(worn) by the cylinder walls.
Then when the engine cools down the pistons contract but now they are thinner because of getting worn = too much clearance.

The other is fuel wash from overly rich mixtures.
If there is too much fuel going into the cylinders it can wash away the oil from the rings and cylinder walls.
That leads to wear on both.

Neither may be the case, just saying that these things can cause too much piston to cylinder wall clearance.
So can an improperly machined block/wrong pistons.

 

[CDW6212R]

Ditto, the piston clearances are critical. They need to be as little as possible that the pistons can take. That's part of why forged pistons can be harder to run long term on the street. Forged pistons have to have more clearance because they expand a little more than cast crap.

That's where piston selection is a big factor. You want pistons that can survive the application, and there are some different aluminum mixtures which can run at tighter clearances, even forged choices.

Hopefully those Wiseco pistons are still okay and can be used again. Wiseco makes great pistons and clearanced right they can take a ton of abuse. That's a lot of why they are an expensive brand, they are worth it if the engine needs it.

 

[Dono]

Thanks John. Fuel wash could definitely have been a start of this.
When James was trying to get the idle I was dealing with a super rich condition for a while.

Don, I think the pistons are ok. Maybe even the block, but I want to have clearances as tight as possible, so there is a very good chance a different block will need to be re-machined and used.

I don't want a sloppy motor, and would rather pay to make sure its all good.

 

[Dono]

Just checking in.
-Crank NFG
-Here's a cut/paste from the machinist on the piston to wall clearance "we are at .0075/.008 piston to wall clearance.... you pistons have collapsed at least .002"

These were Wiseco pistons, so I have no idea what happened with the 'collapsing'.

Machinist's recommendation is to bore the block over for 4.04 pistons and add new pistons to the bill.

He also could see witness marks on a couple of pistons showing they were contacting the crank.

I guess the up side of this is that these issues are being found and rectified. I'm going to have to spend a bunch of time checking TC clearances before the motor goes back on to make sure its not pressing on the crank. I'm not sure why the thrust bearing was taken out this time. That hasn't happened before.

 

[skpyle]

Aw hell...

 

[vroomzoomboom]

tell me again why they said the crank is nfg? because the thrust bearing dug into it? if you remember when that happen to mine, they were able to machine the crank, and get a oversized bearing. that way i didnt have to buy a new crank, and didnt have to rebalance it. now if they are saying the converter was pushing into the flex plate, i would also say get a new trans pump. thats what was my problem.

 

[4pointslow]

Were they forged pistons?
Maybe you can pull the torque converter out to look at the part that goes into the trans pump to see if it is damaged?

 

[Dono]

The crank is 'blue' in multiple locations, and scored all to **** in multiple areas also. I'm quite happy with the recommendation of replacement.
A couple of the crank main caps are blue from heat also. I'm not sure if they will be replaced, but I hope so.
The pistons were Wiseco (I paid for, but couldn't find any markings on the pistons to confirm). The pistons were a forged alloy that expands quite a bit and needed a bigger hole (I'd have to look at work tomorrow to quote the type). No matter what, somehow I ended up with a hole that was way to big. For what I'm doing, I think the pistons were the wrong alloy as I want a fairly tight piston to wall clearance as its a stock block anyway and I don't want a super noisy motor.

In the next few weeks I'll get started again and pull the TC to inspect and replace the seal. I might as well, as I'm there anyway.

I'll inspect the tc gear surfaces carefully. Here is where I'll be taking relevant info from: http://www.americanmuscle.com/tci-torqueconverter-auto-8010-install.html

I never had an issue with thrust bearing before, so I'll be very careful and make sure measurements are good.

 

[gmanpaint]

I just got caught up. I am at a loss for words, other then to say.... I'm sorry all this has happened. I might have thrown a match at it if it was me.

 

[Dono]

Lets just say all I want to do is get this running.
I haven't touched anything since the motor came out.

I was so excited when I started this 2 years ago. Now all I feel is dread.

 

[Josh P]

Lets just say all I want to do is get this running.
I haven't touched anything since the motor came out.

I was so excited when I started this 2 years ago. Now all I feel is dread.

I wish you better luck. That m90 I got from you will spin again this year.

 

[Dono]

Ok, that's fantastic news!