96 Beretta Project

[Superdave]

Dave, I thought you swapped pistons once??

Just 1 when i spun that rod bearing. It's dented now too.

[3400-95-Modified]

Ok cool, I was hoping you would say that. Did you ever notice an issue with the valves after that happened? It didn't look like they were bent any to me, but I didn't get them out of the head yet.

And yes the cam duration is 240@.50 as noted though I don't think this is a regular occurrence, I think it was a one time thing when my timing chain went to hell, because it was BADLY stretched.

More Pics

You cant complain about these bearings.







But these on the other hand... YUCK! second time this happened too... Time for SBC bearings.





Total destruction



Better pics of the pistons

[CNCguy]

Jon
Out of curiosity, what brand were the cam bearings and how were the oil holes oriented?

[3400-95-Modified]

Sealed power IIRC, and I also the center two bearings the oil holes were at 4 or 5 o'clock which also IIRC is how stock was orientated.

I'm half tempted to orientate them with the oil holes at 6 o'clock since it seems that the bottom of the center bearings are where most of the force is.

Maybe this is my issue?

The trend in modern engines has been toward higher operating temperatures and higher valve train loads. Babbitt is limited in its ability to survive under these conditions due to its relatively low strength. When babbitt cam bearings are installed under these demanding conditions, the lining may extrude or fatigue. Fatigue can be identified by craters in the bearing surface where sections of lining material have flaked out.

http://www.engineparts.com/it_cambrgs.asp

I think this is the set that I used...

http://www.summitracing.com/parts/FEM-1492M/

Summit also lists this,

http://www.summitracing.com/parts/CLE-SH1364S/

Says it fits a 3.1 and 3.4... but ending years are 2003 and such... Thats odd...

I think I will be buying these though... if in fact 69 camaro 350 bearings fit... I have yet to find the exact part number that others have used.

http://www.summitracing.com/parts/CLE-SH1349S/

[3400-95-Modified]

I'm half tempted to replace all the bearings with Clevite's just to be sure they will last. Granted my lower end looks beautiful, but Better safe that sorry?

These are the part numbers I have... PLEASE chime in if I'm way off here.

Cam bearings
SH1349S Material: AL-3

Rod Bearings
CB1238P Material: TM-77
or
CB1238A Material: AL-5

Main Bearings
MS2037P Material: TM-77
or
MS2037A Material: AL-5 (Cant seem to find standard size though)

Which do you guys recommend? the Aluminum ones? or the TriMetal for the rod and crank? I'm already definitely planning on going with the AL-3 cam ones since the babbitt Sealed power ones I've used have BOTH now shown signs of being over stressed.

[IsaacHayes]

Dave, have you pulled the cam yet to look at your cam bearings?

[3400-95-Modified]

I just sent him a PM asking him that... As well as what part number he used.

[geldartb]

that's what i was trying to find out with the cam bearings and got no answer in the other thread.
just trying to find out what everyone who was using them was using for brand and what year/years they used to buy them.

i might pull mine apart to check stuff. it still looked good when i sealed it up a few months back but id like to check the cam bearings. still got a few months left till im gonna drive it.

[3400-95-Modified]

I found out that standard duty bearings are part number SH-290S those are the same babbitt type material as stock 60* bearings, BUT the other number listed is SH-1349S which is the Al-3 material, (Aluminum) for Heavy Duty application.

here's the info

[geldartb]

i was wondering about the heavy duty version. guess you just solved my question.

looks like ill be getting the heavy duty version.

Jon how long did your stock ones last with the new cam or did you initially start out with the swapped bearings.

[Superdave]

Dave, have you pulled the cam yet to look at your cam bearings?

Not yet, I will before the engine goes back together though. might be another month or so..

[3400-95-Modified]

Just dropped some cash today...

Got the Clevite perfect circle TM-77 main and rod bearings, and the Clevite Perfect Circle AL-3 cam bearings for a 350. I also got a new PTFT rear main and a timing cover set.

I'm debating on getting a lower intake bolt set, and a new oil pan gasket...

I figured for under 50bux it was worth replacing the main's and rod bearings since I'm in there and they are all coming out anyways. I'm also debating getting the bottom end balanced...

[1988GTU]

Just dropped some cash today...

Got the Clevite perfect circle TM-77 main and rod bearings, and the Clevite Perfect Circle AL-3 cam bearings for a 350. I also got a new PTFT rear main and a timing cover set.

I'm debating on getting a lower intake bolt set, and a new oil pan gasket...

I figured for under 50bux it was worth replacing the main's and rod bearings since I'm in there and they are all coming out anyways. I'm also debating getting the bottom end balanced...

If you are going that far..... new slugs, shot peened rods, and full balance. You know you cannot resist!

[3400-95-Modified]

If you are going that far..... new slugs, shot peened rods, and full balance. You know you cannot resist!

50 bux for bearings, and maybe a couple bills for a lower end balance... vs adding another 500+ for slugs and 200+ for rods... HRMMM... wanna contribute to my go fast fund... I don't think its large enough. LOL

I still think the stock lower end components should hold up fine.

Forged stuff is coming in a few years when I can afford to build an entire second motor.

[1988GTU]

50 bux for bearings, and maybe a couple bills for a lower end balance... vs adding another 500+ for slugs and 200+ for rods... HRMMM... wanna contribute to my go fast fund... I don't think its large enough. LOL

I still think the stock lower end components should hold up fine.

Forged stuff is coming in a few years when I can afford to build an entire second motor.

You should become a doctor, you sure do have patients!