The Ford Barn

CSArno · 02-10-2016, 04:38 PM

This 8BA was rebuilt by Walt Dupont in Gardiner Maine. This is the very first time this engine was turned over after being rebuilt. Its a little loud with no exhaust. You be the judge on how the rebuild came out.
I haven't stopped smiling for hours

https://youtu.be/dUigL0Sya0A

Thanks guys for all your help today!

prpmmp · 02-10-2016, 04:52 PM

Get ready for OLRon to rip you a new one for running a new rebuild on a stand

Pete

CSArno · 02-10-2016, 05:12 PM

We only ran it long enough to get up to temp and make sure everything was good. Thats it. Its going in my F1 this week if I have to freeze half to death doing it! I'm a big fan of break 'em in like you drive 'em.

47Sooner · 02-10-2016, 05:52 PM

Quote:

Originally Posted by prpmmp

Get ready for OLRon to rip you a new one for running a new rebuild on a stand

Pete

Sounds great. So what's the issue with running one on a stand ?

Ol' Ron · 02-10-2016, 06:09 PM

Well do the same thing Walt did. I fire it up on my wooden run in stand. I check for oil pressure, bad sounds and keep the revs up to 1500/2K for cam brake in. Get her hot, shut down, cool off and re torque the heads. Give it to the customer. He should drive it like he stole it. Re torque the headsa fter 3 heat cycles, and enjoy it.

flatjack9 · 02-10-2016, 09:14 PM

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Quote:

Originally Posted by 39topless

I would also be worried about running an engine with no exhaust manifolds.

Why?

JSeery · 02-10-2016, 09:36 PM

On an OHV engine with the short desistance between the exhaust valve and the exhaust port that can be an issue. On a flathead the is considerable distance between the exhaust valve and the open exhaust post.

Binx · 02-10-2016, 10:04 PM

As I recall, running long and hard with open exhaust then decelerating will tend to warp hot exhaust valves by pulling in cooler air from the exhaust side due to the vacuum and cam. I really don't think this video portrays that.

Lonnie

Bored&Stroked · 02-10-2016, 10:06 PM

What JSeery said - there 'supposedly' can be a temperature shock when doing this on a OHV (so the story goes) - stories about valves having issues, etc - can't say that I've ever heard or known of anybody actually having an issue (just sayin!).

I've learned, there are so many often repeated stories in our world - one has to wonder how many actually ever happened to anybody - and if "the claims made" had anything to do with the 'cause' as stated?

I have my doubts about this old story (even on a short-runner OHV) . . . as I have a really hard time imagining how a bunch of cold air somehow jumped into the exhaust port and hurt the head or valve . . . I call BS on this old whole wive's tale!

Anybody have FIRST HAND knowledge of an issue?

JSeery · 02-10-2016, 10:15 PM

LOL, I don't know of any first hand experience because I have never seen or heard on anyone running an OHV engine with no header at all. I'm sure it has been done, but not by anyone I know!

JSeery · 02-11-2016, 12:34 AM

Don't think so. Pressure waves can attempt to push exhaust back into the cylinders even with tuned headers. Headers can be tuned to a specific RPM range to achieve a negative pulse as the exhaust valve opens to help scavenge the cylinder. At half that RPM range a positive pulse is present as the exhaust opens which impedes the cylinder evacuation. I doubt any of this works well in a flathead because of the shape and design of the exhaust passages. Somewhat like the addition of a divider in the center port where the two exhaust ports come together. That seems like a no brainer and you would think substantial horsepower grains, yet dyno test show very little gain. Just part of the oddities of a flathead.

CSArno · 02-11-2016, 11:20 AM

Well, my money (and it was MY money) is on Ol' Ron and Walt knowing what they are doing and not taking a chance on screwing up an engine they just spent many many hours building. Just don't see what throwing a set of headers on would have done for us. I suppose anything is possible in theory.

02-10-2016, 04:52 PM	#2
prpmmp Senior Member Join Date: Jun 2013 Location: west grove Pa. Posts: 238	Re: 8BA rebuild test on the stand Get ready for OLRon to rip you a new one for running a new rebuild on a stand Pete

02-10-2016, 05:12 PM	#3
CSArno Senior Member Join Date: Feb 2015 Location: Maine Posts: 378	Re: 8BA rebuild test on the stand We only ran it long enough to get up to temp and make sure everything was good. Thats it. Its going in my F1 this week if I have to freeze half to death doing it! I'm a big fan of break 'em in like you drive 'em.

02-10-2016, 06:09 PM	#5
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,903	Re: 8BA rebuild test on the stand Well do the same thing Walt did. I fire it up on my wooden run in stand. I check for oil pressure, bad sounds and keep the revs up to 1500/2K for cam brake in. Get her hot, shut down, cool off and re torque the heads. Give it to the customer. He should drive it like he stole it. Re torque the headsa fter 3 heat cycles, and enjoy it.

02-10-2016, 09:36 PM	#7
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 8BA rebuild test on the stand On an OHV engine with the short desistance between the exhaust valve and the exhaust port that can be an issue. On a flathead the is considerable distance between the exhaust valve and the open exhaust post.

02-10-2016, 10:04 PM	#8
Binx Senior Member Join Date: Oct 2011 Location: Gloucester VA Posts: 1,042	Re: 8BA rebuild test on the stand As I recall, running long and hard with open exhaust then decelerating will tend to warp hot exhaust valves by pulling in cooler air from the exhaust side due to the vacuum and cam. I really don't think this video portrays that. Lonnie

02-10-2016, 10:06 PM	#9
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,234	Re: 8BA rebuild test on the stand What JSeery said - there 'supposedly' can be a temperature shock when doing this on a OHV (so the story goes) - stories about valves having issues, etc - can't say that I've ever heard or known of anybody actually having an issue (just sayin!). I've learned, there are so many often repeated stories in our world - one has to wonder how many actually ever happened to anybody - and if "the claims made" had anything to do with the 'cause' as stated? I have my doubts about this old story (even on a short-runner OHV) . . . as I have a really hard time imagining how a bunch of cold air somehow jumped into the exhaust port and hurt the head or valve . . . I call BS on this old whole wive's tale! Anybody have FIRST HAND knowledge of an issue?

02-10-2016, 10:15 PM	#10
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 8BA rebuild test on the stand LOL, I don't know of any first hand experience because I have never seen or heard on anyone running an OHV engine with no header at all. I'm sure it has been done, but not by anyone I know!

02-11-2016, 12:34 AM	#11
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 8BA rebuild test on the stand Don't think so. Pressure waves can attempt to push exhaust back into the cylinders even with tuned headers. Headers can be tuned to a specific RPM range to achieve a negative pulse as the exhaust valve opens to help scavenge the cylinder. At half that RPM range a positive pulse is present as the exhaust opens which impedes the cylinder evacuation. I doubt any of this works well in a flathead because of the shape and design of the exhaust passages. Somewhat like the addition of a divider in the center port where the two exhaust ports come together. That seems like a no brainer and you would think substantial horsepower grains, yet dyno test show very little gain. Just part of the oddities of a flathead.

02-11-2016, 11:20 AM	#12
CSArno Senior Member Join Date: Feb 2015 Location: Maine Posts: 378	Re: 8BA rebuild test on the stand Well, my money (and it was MY money) is on Ol' Ron and Walt knowing what they are doing and not taking a chance on screwing up an engine they just spent many many hours building. Just don't see what throwing a set of headers on would have done for us. I suppose anything is possible in theory.