The Ford Barn

Fredb_ · 11-27-2013, 10:26 PM

My 81a has .40 pistons with very slight ridge at top of cylinder wall. I am not interested in boring this block, but want to make sure there are no cracks, then just use ridge reamer and cylinder hone. I prefer to use as many of the parts I pulled out as possible, crank, cam, pistons, rods. I plan on replacing most/all of the valve assembly. Is sonic testing really recommended in my case? The reading I've done suggests it is used more to determine how much spare metal you have in your cylinder walls prior to boring. Any suggestions for me appreciated.

41ford1 · 11-28-2013, 08:24 AM

You might want to do a pressure check. I would not bother with a sonic test. Check your piston clearance. That will determine if you need the next size over bore. Your plan sounds fine to me. Rings, bearings(if needed), and a valve job, your basic rebuild. That will give you a fresh engine at a minimal expense.

Ol' Ron · 11-28-2013, 08:36 AM

YUP! Also going to the 49/53 style guids and valves is another plus. Make sure to check valve length, I think the 49.early 51 are the same length.

Fe26 · 11-28-2013, 04:30 PM

Magnafluxing is also an option, it is a reliable and relatively inexpensive way to determine the quality of your block.

Fredb_ · 11-29-2013, 05:45 PM

Yes, I was planning on magnafluxing the block minimally. Is there any issues with throwing the stock CAM back in with new lifters? I like the idea of using the newer guides. What's the best way to get the specs on guides and valves to use? Thanks for the tips guys!

Karl Wolf · 11-29-2013, 07:41 PM

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Talk to the person you will buy from about your questions... Then a couple more. Reds Headers is a good place to start...
A reground cam is not a huge expense... If things were to go other than the way you want, it's gotta be frustrating to go back into an engine to salvage expensive parts cause you decided to economize on a $100 part. I suggest a moderate performance cam grind...

Magnaflux and pressure check do different things.. Not all cracks leak... Pressure check will find water leaks that you will not find with magnaflux...
Both should be done on a new acquisition before investing lots of money.
On the other hand, if you've been running an engine for a while, having no overheat or water issues, magnaflux will probably do.
Karl

Fredb_ · 12-02-2013, 12:17 AM

Thanks Karl sounds like good advice.

11-27-2013, 10:26 PM	#1
Fredb_ Senior Member Join Date: May 2013 Location: Coos Bay, OR Posts: 641	Block checking My 81a has .40 pistons with very slight ridge at top of cylinder wall. I am not interested in boring this block, but want to make sure there are no cracks, then just use ridge reamer and cylinder hone. I prefer to use as many of the parts I pulled out as possible, crank, cam, pistons, rods. I plan on replacing most/all of the valve assembly. Is sonic testing really recommended in my case? The reading I've done suggests it is used more to determine how much spare metal you have in your cylinder walls prior to boring. Any suggestions for me appreciated.

11-28-2013, 08:24 AM	#2
41ford1 Senior Member Join Date: May 2010 Location: ManchVegas, New Hampshah Posts: 1,589	Re: Block checking You might want to do a pressure check. I would not bother with a sonic test. Check your piston clearance. That will determine if you need the next size over bore. Your plan sounds fine to me. Rings, bearings(if needed), and a valve job, your basic rebuild. That will give you a fresh engine at a minimal expense. __________________ You are never to old to enjoy your childhood. Forty1fordpickup on the HAMB.

11-28-2013, 08:36 AM	#3
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,889	Re: Block checking YUP! Also going to the 49/53 style guids and valves is another plus. Make sure to check valve length, I think the 49.early 51 are the same length.

11-28-2013, 04:30 PM	#4
Fe26 Senior Member Join Date: May 2010 Location: Sydney, Australia Posts: 949	Re: Block checking Magnafluxing is also an option, it is a reliable and relatively inexpensive way to determine the quality of your block.

11-29-2013, 05:45 PM	#5
Fredb_ Senior Member Join Date: May 2013 Location: Coos Bay, OR Posts: 641	Re: Block checking Yes, I was planning on magnafluxing the block minimally. Is there any issues with throwing the stock CAM back in with new lifters? I like the idea of using the newer guides. What's the best way to get the specs on guides and valves to use? Thanks for the tips guys!

11-29-2013, 07:41 PM	#6
Karl Wolf Senior Member Join Date: May 2010 Location: Mill Valley,Ca. Posts: 1,509	Re: Block checking Sponsored Links (Register now to hide all advertisements) Talk to the person you will buy from about your questions... Then a couple more. Reds Headers is a good place to start... A reground cam is not a huge expense... If things were to go other than the way you want, it's gotta be frustrating to go back into an engine to salvage expensive parts cause you decided to economize on a $100 part. I suggest a moderate performance cam grind... Magnaflux and pressure check do different things.. Not all cracks leak... Pressure check will find water leaks that you will not find with magnaflux... Both should be done on a new acquisition before investing lots of money. On the other hand, if you've been running an engine for a while, having no overheat or water issues, magnaflux will probably do. Karl Last edited by Karl Wolf; 11-29-2013 at 07:49 PM.

12-02-2013, 12:17 AM	#7
Fredb_ Senior Member Join Date: May 2013 Location: Coos Bay, OR Posts: 641	Re: Block checking Thanks Karl sounds like good advice.