Top end noise

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7

72DartSwingerV8

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I take my car to the alignment shop yesterday and it drives and sounds great. I go to pick it up today and the guy says that there is a clattering in the top end, I listen to it, and sure enough it's there. I already broke in the engine for the 20 minutes at 3000rpm and then 10 minutes at 2000rpm and drove it to the alignment shop with no problems. But now there is a noise that is bad enough to have to tow it home. I'm thinking that it's valvelash, but I have no idea how to fix that with the rocker arm assembly since it's not adjustable. Here's my build as far as heads and valvetrain go:
1.88 int
1.60 exh
stock 318 72' heads milled 20 thou
stock rocker arms
purple shaft 340 specs cam
purple shaft lifters

ANy help is greatly appreciated.

Jake
 
Good oil pressure? Hopefully the mechanic didn't wail on the car on the "test ride". First things first, pull your valve covers and tell us what you find. Hopefully the rocker shafts were installed with the oil holes in the correct position.

Did you check lifter preload when installing the valvetrain?
 
Oil pressure has always been good, about 60 when I first ran it. I'm afraid of that too, the guy said they didn't even test drive it because the sound came up but I'm gonna check the mileage on the receipt. Oil holes are in the right spot, I know that because I put them on backwards then fixed them. I didn't check preload as they all seemed snug. How do you test preload?
 
72DartSwingerV8 said:
Oil pressure has always been good, about 60 when I first ran it. I'm afraid of that too, the guy said they didn't even test drive it because the sound came up but I'm gonna check the mileage on the receipt. Oil holes are in the right spot, I know that because I put them on backwards then fixed them. I didn't check preload as they all seemed snug. How do you test preload?
Click to expand...

I like to use a dial indicator with a magnetic base during engine assembly with the indicator rod right on the lifter plunger before the intake is installed. This is the most accurate way but won't really work with non-adjustable rockers without loosening and tightening the rocker shafts 8 times. You could use the thick feeler gauge and scratch awl method and be close enough for government work. The only way you can adjust your preload with non-adjustable rockers is by purchasing longer or shorter pushrods.

I'm a big proponent of adjustable rockers on all builds. As old as these engines are and not knowing who's had there greasy mitts on 'em over the years leaves a lot to chance.

Anyway, I'd pull those valve covers first and see what's up.
 
Pull the valve covers and see if there is any play/looseness in any of the rocker arms.
 
What could be causing this:
100_2433.jpg


I idled the car and pulled spark plugs until it stopped making the noise. Of course, it was cylinder 7. I take the valve cover off, everything looks fine. Push on the rocker on the intake valve in 7, it's loose; bad lifter. I take the lifter out and it's gone. The bottom of it is worn down almost an 1/8th inch from a new one. So much that there's a hole in the bottom, causing it not to hold oil. Expecting a destroyed camshaft, it's fine. I thought that the camshaft was supposed to go before the lifters. What the hell is going on? Have any of you seen this before? I'm thinking there might be too much preload on everything; causing the grinding. I'm currently baffled.

Help is always appreciated from you guys,

Jake

100_2431.jpg

100_2434.jpg
 
I had the same thing on a Ford 3.8, bad lifter or soft lobe. Either way I think you got to clean out the motor and replace the cam and lifters.
 
pull the front cover off and pull the cam to replace it with a new one, change oil filter and oil along with adding some stp for the next cam break in, use a 20 50w weight oil.
 
How do I prevent this from happening again? THe cam is new and lifters are new as well. I broke in the engine according to specs. What else can you do?
 
Pull the engine, disassemble, inspect crank, bearings, rings & oil pump. May need to replace bearings & polish the crank.

The way to prevent it for sure is to run a hydraulic roller cam.

Sorry this happened to you. Been there, done that. It sucks.
 
I just rebuilt the whole damn engine. It just doesn't make sense to me. You have to roll a dice to see if a brand new cam won't flatten?
 
72DartSwingerV8 said:
I just rebuilt the whole damn engine. It just doesn't make sense to me. You have to roll a dice to see if a brand new cam won't flatten?
Click to expand...

no not really, just takes extra care in set up.

the only chance left after that...is if the core has porosity issues....

What cam specs and spring psi do you have?
did you make sure all the lifter spun freely in the bores?
did you break it in 2200-2800 pm, fluctuating rpms initially and then every 3-5 minutes of the 20-30 min process?

if you are worried, one of us n.san diego guys can come over and assist in making sure all is done to insure the success of your new cam.
 
318 heads with 20 thousands off.... did the 340 spec cam make the valve springs have coil bind...
 
Stuff a roller in it and never worry about it again.
 
racerkilla said:
318 heads with 20 thousands off.... did the 340 spec cam make the valve springs have coil bind...
Click to expand...

nah....figure the factory head gasket was .019 thick and his new ones are .045...


1970Duster said:
Stuff a roller in it and never worry about it again.
Click to expand...

there ya go, let the fear push u into throwing more money at it..lol!
 
72DartSwingerV8 said:
http://www.jegs.com/i/Mopar-Performance/312/P4452761/10002/-1?parentProductId=746961

That's the cam I have in there.

My mechanic told me to break it in at 3,000 for 20 minutes. I then ran it at 2000 rpm for 10 minutes. ALl the lifters spun.

I guess I just need a reason why this happened for mental stability.
Click to expand...

bummer...that is a good cam.

I had a purple shaft '.528 solid' get into porosity on one lobe, didnt waste it...but I knew it was a matter of time, so I bought another one and all was good after that..

typical porosity in the casting, thats hit and miss...and the only way to get the company to even acknowledge it...is to catch it in the early stage when the lobe is still good but shows lil air pockets the size of a rust spec/pen s roller tip.


so what was the seat pressure set to?
 
was the oil system primed before it was started.....did you crank on the engine alot before it started...was the camshaft coated with moly lube

you dont need to spend a grand on a roller....
 
cant be springs they all would be wipe,I think its just one bad lifter, all other lobs are fine right? Maybe a valve was sticking a tad puting to much preasure on that said #7.Still total bummer.:violent1:
 
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