348 trouble

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Larry Ricci

Member
Picked up a 60 chevy bel air with a 348 stated fresh rebuild drove car 4 miles to get inspected and lost a cylinder pulled valve covers motor is spotless inside broken rocker arm noted and bent push rod rocker ball pulled thru the rocker arm upon closer investigation all the rockers were cracked or stressed at the end of the slots so I assume a rocker bind also valve lash was super loose to try to compensate for this issue. I inherited this car and do not know who did the work I pulled the motor any advice also what cam lifter spring rockers push rods to use or a kit for mild street use
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
Welcome Larry,Post a picture of the rocker arms that broke please.This sounds like whomever "rebuilt"this engine used the aftermarket Elgin replacement rockers.Those things are JUNK even for a stock rebuild.If that's the case get a set of Comps roller tip rockers from Show Cars and the number of stock replacement push rods.Without knowing what was used in the way of pistons go conservative if you want to do a cam upgrade.Assuming a 9..5-1 piston[most common] the biggest cam that you can use without modifing pistons is Show Cars 0950 which is 218 in.230 ex.@.050 and it's a very good match for these engines as a mild streeter Get the "edge orfice" style of lifters from Howards Cams to help with preventing cam wear.You can get Comp stock .080 wall push rods from Show Cars and they can get you the springs from Comp.
 
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Larry Ricci

Member
Thanks guy I guess the point you have all made is I don’t know what I have. This is not how I do things. I pulled the motor and will bring it to my engine builder I have raced wingless sprint cars and dirt mods for years this car belonged to my brother in-law and sat in his shop for years it is a beautiful car and worth investing the time and money a good check of the bottom end and see where it takes me.
 
wristpin

wristpin

Well Known Member
Fresh build with no idea who built it and parts breaking off within 4 miles and as James says "valves hitting pistons"...maybe or maybe not but Id rather be safe than sorry. My 2 cents my friend
 
boxerdog

boxerdog

Well Known Member
Supporting Member 5
I'd try some of what Don recommended first, but I am lazy and it could well be Elgin rockers here. Easy enough to check P/V without pulling engine or heads. But...if it's an exceptional car, and Larry is a perfectionist, pull it out! Then you guys can go to work spending OPM as usual!
 
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427John

Well Known Member
Another possibility could be too long a pushrod causing a geometry that gets the rocker too close to the end of the slot,he did say that the slot ends showed damage.I would verify the valvetrain components to be correct,but do so by rolling the engine over by hand just in case there are clearance issues.With unknown history there's no telling whats in there.
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
My reason for blaming the rocker arms is that all the failures that I've seen posted of these things were that they were cast,not stamped.I've never seen a stamped rocker crack.The Elgin rockers are "investment' cast.
 
chuckl

chuckl

Well Known Member
64ss409 said:
Might be chinese rockers.
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Don Jacks said:
My reason for blaming the rocker arms is that all the failures that I've seen posted of these things were that they were cast,not stamped.I've never seen a stamped rocker crack.The Elgin rockers are "investment' cast.
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:yup. :yup. Look for the numeral "43" etched on the underside of the rocker on the valve end. These are extremely poor quality, cast rockers that not only have a cast-in twist, but are very brittle. I had two complete failures (intake and exhaust) and the rest were cracked, some major. Show Cars has stopped carrying them (Elgin). Anyone with these junk rockers--Throw them away before you lose an engine. I was very lucky, mine failed on start after cooling for 2 hours.
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
Investment cast garbage is what those are.Welcome aboard Larry.If you have any questions about what parts are needed for this engine to do what you want it to do please let us help you.There's a lot of misinformation running around out there about these engines and we wouldn't want you to fall victum of it.Besides,having another racer aboard is never a bad thing.
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
I'd be quessing but i think that those would be stock replacement stuff.They're prretty weak,easy to bend.I tend to think that the build parts were bought in a Kit form such as is sold by Falcon Global.The quality of these cheap parts is to me suspect.These kits are a good way to save time because you can't always go to your local parts house and get what you need.There is good stuff for them out there you just have to look.
 
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