The Ford Barn

dono50 · 02-14-2021, 05:42 PM

Pulled heads and intake and found 8 valves with excessive valve lash
Used the #1 TDC compression, adjust both valves, rotate 90 degrees, the adjust both valves based on firing order. Worked great, found 8 valves with excessive lash and replaced with NORS TRW valves ground to fit.
Started engine today, valves are quiet but have a knock at idle that seems to disappear when revving engine.
Suspect head clearance or rod hitting 8RT oil pan. Haven’t checked anything yet, a little frustrated at this point.
Question..If I short out each cylinder one at a time will I be able to isolate a head clearance problem? What’s the best method ?
Thanks, Bob

Lawrie · 02-14-2021, 05:51 PM

NO, you may be lucky enough to look in to the piston with one of those cameras on a stick thing, but head off is the best way.
Lawrie

swedishsteel · 02-14-2021, 06:09 PM

Had a fresh built "36 lb that had a slight knock at idle that went away as revs went up. Ended up the machinist had put in only seven new wrist pin bushings. Old one was the knock.

Mart · 02-14-2021, 06:18 PM

Piston to head clearance would be ok at idle but noisier when revved.

I didn't realise it at the time, but I had that problem with this motor in this video from 2010.

https://youtu.be/hBuyhSecfyo

You can hear the knocking when I rev it.

dono50 · 02-14-2021, 06:29 PM

That’s a possibility, should show up shorting out the cylinders, I would think.

dono50 · 02-14-2021, 07:10 PM

Sponsored Links (Register now to hide all advertisements)

Thanks for the video, you are a talented guy, for sure.
Doesn’t sound like my knock is a head clearance problem after reviewing your info and the audio of your knock.

02-14-2021, 05:51 PM	#2
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,212	Re: 8BA noisy valve update NO, you may be lucky enough to look in to the piston with one of those cameras on a stick thing, but head off is the best way. Lawrie

02-14-2021, 06:09 PM	#3
swedishsteel Senior Member Join Date: Jan 2011 Posts: 342	Re: 8BA noisy valve update Had a fresh built "36 lb that had a slight knock at idle that went away as revs went up. Ended up the machinist had put in only seven new wrist pin bushings. Old one was the knock.

02-14-2021, 06:18 PM	#4
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,745	Re: 8BA noisy valve update Piston to head clearance would be ok at idle but noisier when revved. I didn't realise it at the time, but I had that problem with this motor in this video from 2010. https://youtu.be/hBuyhSecfyo You can hear the knocking when I rev it.

02-14-2021, 06:29 PM	#5
dono50 Senior Member Join Date: May 2010 Location: Bradenton,Fl/ Cheshire,Ct Posts: 710	Re: 8BA noisy valve update That’s a possibility, should show up shorting out the cylinders, I would think.

02-14-2021, 07:10 PM	#6
dono50 Senior Member Join Date: May 2010 Location: Bradenton,Fl/ Cheshire,Ct Posts: 710	Re: 8BA noisy valve update Sponsored Links (Register now to hide all advertisements) Thanks for the video, you are a talented guy, for sure. Doesn’t sound like my knock is a head clearance problem after reviewing your info and the audio of your knock.

02-14-2021, 05:42 PM	#1
dono50 Senior Member Join Date: May 2010 Location: Bradenton,Fl/ Cheshire,Ct Posts: 710	8BA noisy valve update Pulled heads and intake and found 8 valves with excessive valve lash Used the #1 TDC compression, adjust both valves, rotate 90 degrees, the adjust both valves based on firing order. Worked great, found 8 valves with excessive lash and replaced with NORS TRW valves ground to fit. Started engine today, valves are quiet but have a knock at idle that seems to disappear when revving engine. Suspect head clearance or rod hitting 8RT oil pan. Haven’t checked anything yet, a little frustrated at this point. Question..If I short out each cylinder one at a time will I be able to isolate a head clearance problem? What’s the best method ? Thanks, Bob