Lifters rattling after hard accelleration

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jimharvard

jimharvard

JimHarvard
FABO Gold Member
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Location
Pittsburgh, Pennsylvania
there have finally been a few sunny days here in pittsburgh allowing me to drive my 340 barracuda to some of the local cruises. today while leaving one of these events i decided to abuse the car a bit so i did a strong first gear dash with a quick second gear shift with a nice "chirp" of the tires. since i was running out of road i slowed a bit for third and forth. when the 750 holley was done attempting to suck the hood into the carb and the 340 was a bit quieter, i noticed the lifters were really rattling. i quickly looked at the oil pressure guage preparing for an emergency engine shut down but the pressure was fine. the lifters then quieted down and the rattling dissappeared.

the 340 in my car is a 71 and was just rebuilt by the prior owner right before i bought the car. it seems to be a fine engine. i'm going to put a "new" date correct 340 in the car this winter but i do want to run the present engine for the rest of the summer. so do any of you expert FABO wrenches have a suggestion as to why my lifters are rattling after hard accelleration? i'm thinking the prior owner didn't put the windage tray back in the oil pan causing a momentary starving of oil to the pump. does that sound plausible? i'm open to all suggestions.

thanks in advance ...

jim coster, pittsburgh, pa
 
If it's a hi volume pump with a stock pan it's sucking air for a second or two.
 
el5demon...
what's the remedy for this oil stavation problem - different pan, different oil pump? how bout different oil? this motor runs very quiet at all other times other than short dashs.

thanks...

jc
 
If you are running a stock oil pan, you need a standard volume pump.
A high volume pump can suck a pan dry in a stock pan.
You may also try a lighter 5w-20 oil.
Heavy oil is nothing but friction on a engine, run the lightest oil you can get buy with without affecting pressure.
 
Pan with baffles cures it.
It's not the rev that starves it so much as the rapid decelleration makes the rest of the oil go to the front of the pan where it can't get picked up. (maybe the case?)

I'll bet your oil pressure did drop, but came back up before you looked.
 
You would have had to revv it well over 7500 RPM for it to think about sucking the pan dry. At that point it would have probably dropped a valve and threw a rod! Ask me how I know....Lol
Hyd lifter would float the valves if you were really giving it to it.
 
Are you sure the oil level is not low?
 
hey guys... thanks for the advice...
oil level is fine in the motor. i have a nice OEM 340 pan with a factory windage tray. i'll try swapping the pans. if i drop the pan on the present motor and there is no windage tray, that may be the problem. i'll also check the oil pump to see if it is a high capacity pump and drop down to 5w-30.

any other suggestions?
 
krazykuda said:
Or maybe try running an extra half quart over if it's at full when starving.
Click to expand...


That's what i have done and it worked(found out latter it was a dent in the oil pan pushing the pick up tub a little bit.)
 
sireland67 said:
If you are running a stock oil pan, you need a standard volume pump.
A high volume pump can suck a pan dry in a stock pan.
You may also try a lighter 5w-20 oil.
Heavy oil is nothing but friction on a engine, run the lightest oil you can get buy with without affecting pressure.
Click to expand...

In my 340 .030 over and pushing 413 hp I have run nothing but 10W-40 for the last 10 yrs after rebuild and I have had not one issue. Run her til the tack light comes on at 7000 rpm and when the R's begin to drop and mellow out at 3500 the lifters are still quiet so as for the 5w-20 I myself would not recommend running the light of an oil but that is my opinon.
 
I wouldn't worry about a windage tray, if you want to keep the stock pan have some baffles welded in, and use a stock volume pump. Stock pumps on a good engine should show about 20/25 psi at idle in gear 800 rpm and usually no more than 50/60 psi at 3k plus 10/30 10/40 if your seeing more than that you MAY have a H/V pump. Make sure your dip stick is reading correctly also.
 
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