What caused this damage

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Petri.

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Hi you all,i am a new member from sweden but i read here alot and at all the other mopar sites,i have no a-body but i thought this forum can be the place to get some good answers,i have a 300 -67 and a charger -68 and both i have bought from mopar sites from the states,back to the questions.
I just bought a damaged blown 440,i dont have all the data yet but i will get them,this is what i know for now and i opened the engine today.
Bds 8-71 kit for 440
2 holley 750
440 block
stock 440 crank forged
stock 440 rods
pistons speed pro trw L2266F coated on the sides
edelbrock rpm 84cc heads
cam i dont know now but it is a blower cam
The engine is built by one serious firm that drive and build race cars,they also dynoed it and it did only hold for 900miles

The damage is that the first rod att the right side (passenger) is broked and it did hit holes about 1" at bouth sides of the block,that piston is also damaged and the piston at the other side,all the bearings looks like new and there is no major damage to the crank so that i can use again, so the only damage is
1 rod broke
2 pistons
1 intake valve bent
the block

the rods had arp bolts and it did not broke there,it broke just about 1" upp from the rod journal and as i said there is no damage to that journal and the bearings are nice.

the enigine was dynoed at 6psi and it was about 580-600hp,torque i dont know yet before i get the papers and it was sitting in a -31 hot rod

So what can have caused this damage at only 6psi,dont the stock rods hold upp for more,i have been reading some about these pistons and people write that it is a old type heavy piston,true?
Can the piston weight with stock rods and the cylinder pressure caused this?
I think these pistons turns way under the deck?
Good piston for roots engine?
The head gaskets did look nice so i dont think that they failed and enabled water to get in to that cylinder and make the rod to smash of but it is hard for me to say but the gasket looks nice to me

/Petri
 
You did not say how hard it was running when it blew but I would say lost oil pressure and spun rod bearing and boom.
 
67cudafb said:
You did not say how hard it was running when it blew but I would say lost oil pressure and spun rod bearing and boom.
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He did state that the crank was undamaged and the rod broke 1" from the crank rod journal. That would rule out spun bearing.

Stock rod would be the culprit imo....

I would reassemble with quality rods and at least ARP2000 bolts! Those bolts are good to 750hp or the L19 which are good for over 1000hp... Make sure the crank is a forged piece too! BALANCE everything and use a good dampner.
 
Sorry missed that. Hell to get old and blind. Did I read right that has 2 holes in block?
 
Sounds like over revved with weight. I was always told that if the rod fails on the big end but away from the bearing its usually from a flexing rod. That happens with high RPM or an imbalance, and those pistons are forged heavy may as well be made of lead. Super strong but heavy. Does the piston travel in the bore , can you knock it up through the deck? Any evidence of piston seizure. What kind of distortion does the broken ends of the rod show. Got any pics?
 
Just went and reread your post the bent valve is a good indication of an over-rev. Did it have the 6 psi pulley on it when it made its way to you. Just cuz it dynoed at 6 doesn't mean somebody didn't put an 8 on it to try n push the envelope.
 
funwithfuel said:
Sounds like over revved with weight. I was always told that if the rod fails on the big end but away from the bearing its usually from a flexing rod. That happens with high RPM or an imbalance, and those pistons are forged heavy may as well be made of lead. Super strong but heavy. Does the piston travel in the bore , can you knock it up through the deck? Any evidence of piston seizure. What kind of distortion does the broken ends of the rod show. Got any pics?
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I agree with the over-rev too! If this engine was built by the said "Serious" builder they would have used a better rod imo.. Using a stock rod tells me that they weren't to serious with this particular engine!

I built a "Budget" boosted lowdeck with Eagle "H" beams and L19 rod bolts. Decent girdle and a stock forged crank all balanced.
 
i will try to get some pics before i go away on 2 weeks vacation ob sunday

the hole on the other side i think is because the rod hit the pickup and the pickup made the hole, i also think that they reved the engine to far but i cant say how far before i get home from vacation,it was no problem to get that piston out from the cylinder,it was like pushing out any other piston,the people that built it told me that the first time they dynoed that it gave to much hp so they did change the pulley to get it down to 6 psi for the light hot rod and that is how it has been driven on the streets until the damage.

And there is no dampner on the engine,dont no if it was balanced but i assume because it was serious people that built it,they drive dragrace, 7sec 402m

allt the other pistons look like new out of the box.

My plans for this engine is only a cruise/street engine,i will take the crank to a good shop i know and look so its good,buy new h-profil rods and good light weight pistons and find a new 440 block that is a little difficult in sweden and put a girdle on it as you say,i also think the rev took it,what is the max rev of a engine like this? 5000-5500rpm.

The bore was 0.06" and is that ok for a mild blower engine
compression ratio was about 8.7-8.8,little to high or good with the aluminium heads.
I have been reading a lot about mopar bb blower engines and some people say that you dont need a dampner and other say you need a dampner,that is pretty confusing,hopefully i can get a couple of pics tomorrow.

/Petri
 
Petri. said:
i will try to get some pics before i go away on 2 weeks vacation ob sunday

the hole on the other side i think is because the rod hit the pickup and the pickup made the hole, i also think that they reved the engine to far but i cant say how far before i get home from vacation,it was no problem to get that piston out from the cylinder,it was like pushing out any other piston,the people that built it told me that the first time they dynoed that it gave to much hp so they did change the pulley to get it down to 6 psi for the light hot rod and that is how it has been driven on the streets until the damage.

And there is no dampner on the engine,dont no if it was balanced but i assume because it was serious people that built it,they drive dragrace, 7sec 402m

allt the other pistons look like new out of the box.

My plans for this engine is only a cruise/street engine,i will take the crank to a good shop i know and look so its good,buy new h-profil rods and good light weight pistons and find a new 440 block that is a little difficult in sweden and put a girdle on it as you say,i also think the rev took it,what is the max rev of a engine like this? 5000-5500rpm.

The bore was 0.06" and is that ok for a mild blower engine
compression ratio was about 8.7-8.8,little to high or good with the aluminium heads.
I have been reading a lot about mopar bb blower engines and some people say that you dont need a dampner and other say you need a dampner,that is pretty confusing,hopefully i can get a couple of pics tomorrow.

/Petri
Click to expand...

The .060 over could be a problem on most RB's. I know .040 is about as far as you can go unless your machine shop sonic checks the cylinder walls. I went .060 over on the 400 block and sonic checked and returned a .099 thickness on the thinest wall.
Use a dampner even if it is balanced!!! Have the dampner ready to send with the crank, rods and pistons when machined/balanced.

Compression ratio would be ideal at 8.5:1... You can go as high as 9:1.

RPM's really depend on your valvetrain. I am only pushing my lowdeck to 6000 rpm. My buddy has a 526" RB n/a pushing 7000rpm. It has high quality parts though.
 
I would also run .002 oil clearance on mains and rods. Use a High Volume Low Pressure oil pump too.
 
I am not going to venture as to what actually happened when the rod broke, but I will mention a couple of things. The stock rods are not a good rod for a blower engine as the fuel explosion lasts longer and puts more twisting pressure on the rods. The heavy pistons should be a good choice as long as you are not going to rev the engine above 6000 rpm. The theory is that the heavy pistons help take up the shock of the fuel explosion. By all means get a good set of H-beam rods and good bolts.

Jack
 
its pretty hard to say what caused it,but i would be worried running stock rods on a blown build,can you post any pictures of the damage? i might not know much about what went wrong from them but some others on this site has very sharp eyes!

what company built this? if you dont want to put it out here you could send me a PM about it,i have a feeling who it might be.

and of course welcome to the site!
 
Maybe a stuck Exhaust valve Or Wiped out Cam lobe. That could have built up a ton of pressure in that one cylinder. Just a Guess. Otherwise Maybe just needed better Rods and was run too hard/Over revved during down shifting?? Are you going to weld the block to repair it?? Good luck with the project.
 
Petri. said:
This company buildt it.

http://www.c-mr.se/

/Petri
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ok, not the company i thought of, i never heard anything bad about that company.

im not an expert in any way,but the wear on those bearings looks strange to me.

first its odd with wear in the top halfs of the mainbearings like that,and i cant realy wrap my head around what makes the bearing look like the one in the 4th pic since the wear almost dissapears close to the partingline.

the bearing in the 5th pic looks like the crank must have been bending since it looks worn out towards the edges.

the rod bearing looks very beat up to me, could there have been some detonation killing the rods and at the same time flexing the crank?

once again not an expert,its just what i could piece togheter from the visual i realy hope someone with more knowledge will jump in on this and give a better answer.
 
1Fast340 said:
i doubt
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I don't! I have seen failures on LY rods in both small and bigblock on N/A applications!

I would lean more to overrev as stated before. As you stated could have been detonation as well. Who knows for sure?? I didn't see a girdle so cap walk could cause premature bearing wear.
 
Hi again, i have not done anything yet because of time butt i have bought another 440 that i will use the block from, what rods should i go with, dont need the top of the line but not the worst either, what brand of these will do the job, 440source scat eagle or is there any other brand in the same price range, stock length and 0.99 pin i assume? And how about ross pistons?

/Petri
 
If you are looking for floating .990 pins scat and eagle are your best bet. Ebay has some good deals for other brands h beam rods. If you go with pressed 1.094 pins, I went with the 440 source house brand rod with 7/16 arp rod bolts. I was impressed with the quality and my machinist also agreed the 440 source were nice pieces.
 
Thanks, so what is better, floating or press in, i like floating more because they are easier to install.

Petri
 
I'd like to see the tops of the pistons.
A lot of material at the chamfer on the crank.

Hydrolock
 
A couple of piston pics, first piston is the broken one.

20121108_161553.jpg


20121108_161651.jpg

20121108_161644.jpg


20121108_161627.jpg
 
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