The Ford Barn

Shoebox · 08-30-2021, 09:54 AM

A few years back I got the nicest 8BA block I have ever had. It had been stripped, baked, cleaned, mag & pressure tested. So, looking at building in the near future, currently it is 3 3/16 plus 0.60". Not looking to go to the max here, what should I take it out to? I'm thinking of Egge pistons and interested in the Metric Ring Packs that Gosfast (miss him) often spoke of.
Thanks fellas!

tubman · 08-30-2021, 11:50 AM

I know you can go to at least 3 5/16" (.125 over). I have done two so far, and the only problem I ran into was a small casting flaw in one cylinder of the second engine that showed up after the bore job. The machinist said because of it's position and size, we could just run with it, but I decided to sleeve that cylinder (for $85) just to be safe. Other than that, there was plenty of wall left and I have had no problems with either engine.

I know there are some here who have gone to 3 3/8" or even 3 7/16" (the max I have heard of was 3 7/16" +.030; that does scare me). Another reason I like 3 5/16" is that if you look hard enough, you can get the pistons for the same price as standard bore. (I like free cubic inches.) Going larger usually requires more expensive pistons.

Ronnieroadster · 08-30-2021, 02:37 PM

Consider a set of Egge .080 oversize pistons that would fit your desire to not go to the max. Or the next step would be 3-5/16 bore however there is the chance a pin hole flaw will be found its not unusual for that to happen.
Ronnieroadster

supereal · 08-30-2021, 04:18 PM

Over boring a flathead block is dicey, as the cylinder wall thickness varies due to the core shift in casting. In my racing days, we went through lots of blocks to get a maximum increase without breaching a wall. Back then, the junk yards were full of engines. Today the supply of blocks can be very expensive. In one case, we finally had one we could bore
without hitting a sand hole. Our joy was shattered when our car popped a wall when we started it on the trailer at the track!

russcc · 08-30-2021, 06:33 PM

Had the 59L bored out 3 & 5/16, and pressure tested before assembly. Found a very tiny weep hole in 1 cylinder. Bored & sleeved it, and all is well. Got the NOS sleeve from Fred at South Side, and Hans at Advance Engines sleeved it on his RMC boring mill. which bores off the center line vs the deck.

Ol' Ron · 08-31-2021, 12:09 PM

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When I was building engines, my standard overbore was 3 5/16, Did dozens of them. I also did quite a few 3 3/8 with 4 1/8 cranks, which was about as far as you could go back then using stock parts. We also races 2 blocks at 3 7/16. Over a 10/12 span had few bad blocks, one was just to badly rusted and was junked, several were just sleeved.. Today I don't see going beyond 3 5/16, this add over one point in CR and EGGE makes 3 5/16 + .020/,030 pistons for rebuild, but good blocks are getting scarce.
Gramps

Shoebox · 08-31-2021, 07:24 PM

Ron,
Thanks for weighing in on my discussion. You and I have conversed on topics before and your wisdom is always appreciated. I completely agree that good blocks are getting harder to find. I mentioned in my OP that I have this excellent 8BA block that is already 3 3/16 +.060. Ronnieroadster suggested I go with Egge .080 pistons, as I wish to minimally overbore. I'm inclined to go this way, and intend to use 3 rings. Have you ever used Mahle or Wisco pistons, what are your thoughts on brands of rings?
Thanks so much.
Shoebox

40 Deluxe · 08-31-2021, 10:36 PM

Quote:

Originally Posted by supereal

Over boring a flathead block is dicey, as the cylinder wall thickness varies due to the core shift in casting. In my racing days, we went through lots of blocks to get a maximum increase without breaching a wall. Back then, the junk yards were full of engines. Today the supply of blocks can be very expensive. In one case, we finally had one we could bore
without hitting a sand hole. Our joy was shattered when our car popped a wall when we started it on the trailer at the track!

Did you break it in and tune before heading to the track?

Bored&Stroked · 09-01-2021, 06:30 AM

I've not used Mahle or Wisco pistons . . . though would have no problem giving either of them a try. You might check with them all for pricing and delivery - can be a real issue these days.

What I would recommend is picking a bore size that allows you to use a modern ring pack -- like 1.5, 1.5, 3.0 mm rings - with a good moly top ring. When I order my custom pistons from Ross, I only use modern rings - sometimes with a custom bore size that matches the typical metric ring sizes (usually on 1/2 mm boundaries).

Ol' Ron · 09-01-2021, 12:05 PM

No, I'm not familiar with that brand of piston. I use only OEM or Egge pistons. However, depending on the style of piston, the piston to cylinder wall to skirt clearance is critical. For street use a steel strut piston is best as it can be set up the tightest at . 0015/.002. The only 296 engine i ever built has a set of no/name steel strut pistons in it and it's still running after 15 years of use and never used a drop of oil. It was recently replaced with a 294 blown engine. Nice to have a spare engine. good luck.
Gramps

Tim Ayers · 09-01-2021, 03:32 PM

Quote:

Originally Posted by Bored&Stroked

I've not used Mahle or Wisco pistons . . . though would have no problem giving either of them a try. You might check with them all for pricing and delivery - can be a real issue these days.

What I would recommend is picking a bore size that allows you to use a modern ring pack -- like 1.5, 1.5, 3.0 mm rings - with a good moly top ring. When I order my custom pistons from Ross, I only use modern rings - sometimes with a custom bore size that matches the typical metric ring sizes (usually on 1/2 mm boundaries).

When shopping for pistons, I was very tempted to go with Wisco. I'm familiar with them from my dirt bike days from many years ago.

The Wisco auto pistons seemed very high tech. Short skirts, various coatings, etc.

In the end, I went with Ross and a Total Seal metric ring packs for a number of reasons. Like you said, once you start getting into custom sizes, metric modern rings may be the only option.

Shoebox · 09-03-2021, 12:56 PM

Quote:

Originally Posted by Tim Ayers

When shopping for pistons, I was very tempted to go with Wisco. I'm familiar with them from my dirt bike days from many years ago.

The Wisco auto pistons seemed very high tech. Short skirts, various coatings, etc.

In the end, I went with Ross and a Total Seal metric ring packs for a number of reasons. Like you said, once you start getting into custom sizes, metric modern rings may be the only option.

Tim,
As a Kawasaki dealer years ago is where I got my familiarity with Wiseco pistons too. The more I dig into this I believe Ross pistons are in my future. On their website yesterday I saw for flatheads, one part# 80582 which uses conventional ring set, and another larger piston using metric rings. I sent them a message about metric ring availability with the 3.187 size piston but haven't heard back yet. How big did you go with your engine?

Tim Ayers · 09-03-2021, 01:08 PM

Quote:

Originally Posted by Shoebox

Tim,
As a Kawasaki dealer years ago is where I got my familiarity with Wiseco pistons too. The more I dig into this I believe Ross pistons are in my future. On their website yesterday I saw for flatheads, one part# 80582 which uses conventional ring set, and another larger piston using metric rings. I sent them a message about metric ring availability with the 3.187 size piston but haven't heard back yet. How big did you go with your engine?

My engine was already at 3 3/8th. We had to + .030 to get the bores correct. Thankfully, sonic testing proved there was still enough meat even at this large bore size. I got "lucky" with the 5th block.

RonnieRoadster (poster above) built the motor and he knows his stuff when it comes to Ross pistons

I would give Ross a call and talk to their tech team. Ross do have "in stock" items. but they can do anything you want, you just have to ask them.

My pistons had to be custom made and the turn around was approx. 3 weeks.

Good luck with the build and keep asking questions.

supereal · 09-03-2021, 03:33 PM

The engine was run several times before loading it on the trailer. We start it and let it run at a fast idle. The cylinder wall broke after about 20 minutes. I am long past my racing days, but we run a large machine shop in Iowa, where we do lots of reboring and other work, mostly from other shops. Most of the flatheads come from hobbyists and smaller shops. My own '47 convertible got the whole treatment, and has been faultless for the 25 years I have owned it. My age (86) means it is time to sell it so someone else can enjoy!

JWL · 09-03-2021, 05:28 PM

To the original poster: The availability of +.083 pistons should give you a good solution to your question. These were commonly used for replacements when sleeves were removed. If you have problems finding these contact me as I am sure I still have a few sets of these heavy old slugs.

The rush to tout the use of thinner, "metric" rings is another silly, poorly informed, myth as it relates to a common "cruiser" vehicle. Under the normal driving circumstance the best that can be said is quicker break in/wear in is typical. The negative side is less use/mileage before wear takes a toll while there is no measurable improvement in any characteristic important to daily driving.

KiWinUS · 09-03-2021, 05:35 PM

Quote:

Originally Posted by JWL

To the original poster: The availability of +.083 pistons should give you a good solution to your question. These were commonly used for replacements when sleeves were removed. If you have problems finding these contact me as I am sure I still have a few sets of these heavy old slugs.

The rush to tout the use of thinner, "metric" rings is another silly, poorly informed, myth as it relates to a common "cruiser" vehicle. Under the normal driving circumstance the best that can be said is quicker break in/wear in is typical. The negative side is less use/mileage before wear takes a toll while there is no measurable improvement in any characteristic important to daily driving.

JWL. Is this from personal experience.
Thanks
Tony

KiWinUS · 09-03-2021, 06:50 PM

Okay

Ol' Ron · 09-03-2021, 09:06 PM

Ross pistons for street use is a poor choice, as they require a larger piston to wall clearance. Best piston is a tight piston.

08-30-2021, 09:54 AM	#1
Shoebox Senior Member Join Date: Jan 2014 Location: Holmen,Wisconsin Posts: 783	Another overbore question A few years back I got the nicest 8BA block I have ever had. It had been stripped, baked, cleaned, mag & pressure tested. So, looking at building in the near future, currently it is 3 3/16 plus 0.60". Not looking to go to the max here, what should I take it out to? I'm thinking of Egge pistons and interested in the Metric Ring Packs that Gosfast (miss him) often spoke of. Thanks fellas! __________________ I went, I saw, I bought the T shirt 51 Ford Deluxe Tudor 32 Ford roadster 39 Mercury Towncar

08-30-2021, 11:50 AM	#2
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: Another overbore question I know you can go to at least 3 5/16" (.125 over). I have done two so far, and the only problem I ran into was a small casting flaw in one cylinder of the second engine that showed up after the bore job. The machinist said because of it's position and size, we could just run with it, but I decided to sleeve that cylinder (for $85) just to be safe. Other than that, there was plenty of wall left and I have had no problems with either engine. I know there are some here who have gone to 3 3/8" or even 3 7/16" (the max I have heard of was 3 7/16" +.030; that does scare me). Another reason I like 3 5/16" is that if you look hard enough, you can get the pistons for the same price as standard bore. (I like free cubic inches.) Going larger usually requires more expensive pistons.

08-30-2021, 02:37 PM	#3
Ronnieroadster Senior Member Join Date: Dec 2010 Location: East Coast in CT Posts: 1,524	Re: Another overbore question Consider a set of Egge .080 oversize pistons that would fit your desire to not go to the max. Or the next step would be 3-5/16 bore however there is the chance a pin hole flaw will be found its not unusual for that to happen. Ronnieroadster __________________ I use the F word a lot no not that word these words Flathead , Focus and Finish. "Life Member of the Bonneville 200 MPH Club using a Ford Flathead block" Owner , Builder, Driver of the First Ford Flathead bodied roadster to run 200 MPH Record July 13, 2018 LTA timing association 200.921 in one and a half miles burning gasoline. First ever gas burning Ford flathead powered roadster to run 200 MPH at Bonneville Salt Flats setting the record August 7th 2021 at 205.744 MPH

08-30-2021, 04:18 PM	#4
supereal Senior Member Join Date: Jul 2014 Location: Iowa Posts: 1,634	Re: Another overbore question Over boring a flathead block is dicey, as the cylinder wall thickness varies due to the core shift in casting. In my racing days, we went through lots of blocks to get a maximum increase without breaching a wall. Back then, the junk yards were full of engines. Today the supply of blocks can be very expensive. In one case, we finally had one we could bore without hitting a sand hole. Our joy was shattered when our car popped a wall when we started it on the trailer at the track!

08-30-2021, 06:33 PM	#5
russcc Senior Member Join Date: May 2010 Posts: 2,871	Re: Another overbore question Had the 59L bored out 3 & 5/16, and pressure tested before assembly. Found a very tiny weep hole in 1 cylinder. Bored & sleeved it, and all is well. Got the NOS sleeve from Fred at South Side, and Hans at Advance Engines sleeved it on his RMC boring mill. which bores off the center line vs the deck.

08-31-2021, 12:09 PM	#6
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,855	Re: Another overbore question Sponsored Links (Register now to hide all advertisements) When I was building engines, my standard overbore was 3 5/16, Did dozens of them. I also did quite a few 3 3/8 with 4 1/8 cranks, which was about as far as you could go back then using stock parts. We also races 2 blocks at 3 7/16. Over a 10/12 span had few bad blocks, one was just to badly rusted and was junked, several were just sleeved.. Today I don't see going beyond 3 5/16, this add over one point in CR and EGGE makes 3 5/16 + .020/,030 pistons for rebuild, but good blocks are getting scarce. Gramps

08-31-2021, 07:24 PM	#7
Shoebox Senior Member Join Date: Jan 2014 Location: Holmen,Wisconsin Posts: 783	Re: Another overbore question Ron, Thanks for weighing in on my discussion. You and I have conversed on topics before and your wisdom is always appreciated. I completely agree that good blocks are getting harder to find. I mentioned in my OP that I have this excellent 8BA block that is already 3 3/16 +.060. Ronnieroadster suggested I go with Egge .080 pistons, as I wish to minimally overbore. I'm inclined to go this way, and intend to use 3 rings. Have you ever used Mahle or Wisco pistons, what are your thoughts on brands of rings? Thanks so much. Shoebox __________________ I went, I saw, I bought the T shirt 51 Ford Deluxe Tudor 32 Ford roadster 39 Mercury Towncar

09-01-2021, 06:30 AM	#9
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,062	Re: Another overbore question I've not used Mahle or Wisco pistons . . . though would have no problem giving either of them a try. You might check with them all for pricing and delivery - can be a real issue these days. What I would recommend is picking a bore size that allows you to use a modern ring pack -- like 1.5, 1.5, 3.0 mm rings - with a good moly top ring. When I order my custom pistons from Ross, I only use modern rings - sometimes with a custom bore size that matches the typical metric ring sizes (usually on 1/2 mm boundaries).

09-01-2021, 12:05 PM	#10
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,855	Re: Another overbore question No, I'm not familiar with that brand of piston. I use only OEM or Egge pistons. However, depending on the style of piston, the piston to cylinder wall to skirt clearance is critical. For street use a steel strut piston is best as it can be set up the tightest at . 0015/.002. The only 296 engine i ever built has a set of no/name steel strut pistons in it and it's still running after 15 years of use and never used a drop of oil. It was recently replaced with a 294 blown engine. Nice to have a spare engine. good luck. Gramps

09-03-2021, 03:33 PM	#14
supereal Senior Member Join Date: Jul 2014 Location: Iowa Posts: 1,634	Re: Another overbore question The engine was run several times before loading it on the trailer. We start it and let it run at a fast idle. The cylinder wall broke after about 20 minutes. I am long past my racing days, but we run a large machine shop in Iowa, where we do lots of reboring and other work, mostly from other shops. Most of the flatheads come from hobbyists and smaller shops. My own '47 convertible got the whole treatment, and has been faultless for the 25 years I have owned it. My age (86) means it is time to sell it so someone else can enjoy!

09-03-2021, 05:28 PM	#15
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: Another overbore question To the original poster: The availability of +.083 pistons should give you a good solution to your question. These were commonly used for replacements when sleeves were removed. If you have problems finding these contact me as I am sure I still have a few sets of these heavy old slugs. The rush to tout the use of thinner, "metric" rings is another silly, poorly informed, myth as it relates to a common "cruiser" vehicle. Under the normal driving circumstance the best that can be said is quicker break in/wear in is typical. The negative side is less use/mileage before wear takes a toll while there is no measurable improvement in any characteristic important to daily driving.

09-03-2021, 06:50 PM	#17
KiWinUS Senior Member Join Date: May 2010 Location: Charlotte NC KiWi-L100 available here Posts: 2,954	Re: Another overbore question Okay

09-03-2021, 09:06 PM	#18
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,855	Re: Another overbore question Ross pistons for street use is a poor choice, as they require a larger piston to wall clearance. Best piston is a tight piston.