Well I am almost set to do a rebuild on the engine for my '55 Fairlane Club Sedan.. Here is what I have:

1955 ECK block with ECK-C heads (not original to the car but probably out of a Mercury or Canadian Monarch)(I have done a search on this site and can find no discussions regarding the ECK block). As the motor came to me it is extremely clean but has not (in my opinion) been rebuilt. I have the heads off but have not yet turned the block over and pulled out the pistons,crank, cam and lifters.

It is the standard (3.75") bore but has (what appears to me) a significant ridge at the top of the bore. A friend suggested that I bore it out to 3.80" (312 standard bore). Alternatively 3.75 +.060 gives 3.81". Given that 292 pistons seem to be less expensive, is there a reason to use 312 pistons? All things being equal, can a block that was offered only as a 292 in 1955 be bored out to 3.80 or 3.81"? Is there a significant cost in going from the minimum necessary to a larger bore? I have checked the prices on Egge, Silvolite and Sealed Power pistons and the price range is only about $75. Egge cost the most - are they the better option? Is it important that the machine shop have the pistons and rings on hand before doing the work or can I wait to acquire them after the work is done? For cash flow reasons I have to phase my machining costs and parts purchases over 2 or 3 months. Your opinions are most welcome.


Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Hi Mark,



IF you aren’t aware of it, Google www.ford-y-block.com/technical.htm Toggle 'Technical Info.-Ford-Y-Block-com', then toggle the section titled, ‘Block Identification’. John Mummert’s listing indicates that the ECK block was used in ’55 and ’56 in making Ford/Mercury 292 engines. On the same web site under 'Head Casting Numbers', John indicates that the ECK-C heads were used in the states on '55 'Birds and Mercs. FoMoco rated them at 8.5:1 compression on the 292s.



I have had an ECK block overbored for 312 pistons and not had trouble, BUT... to be safe, in boring any engine block oversize there is merit to having the cylinders sonic tested. This will show IF the sand cores used in the making of the water jacket or cylinders shifted in the process of making the sand mold OR during the pouring of the sand mold. –When the metal enters the mold, it can cause the sand cores to move out of their intended position. Knowing the existing wall thicknesses helps to assure that you don’t end up with a thin spot after overboring.



I can think of no advantage to using stock 312 pistons instead of 292 + .060 pistons. Piston pin compression height and piston pin size are the same. From FoMoCo, the piston skirts were different, but only because the 312 piston skirt had to be modified to prevent interference with the crank throws because of the longer stroke of the 312.



Yes, the machine shop should have the pistons before boring the cylinders and doing the honing to final size. Each piston will be individually fit (clearanced) in the cylinder. This measurement is done at 90 degrees to the piston pin measured at the skirt per manufacturer’s recommendation. Different piston manufacturers may have a different clearance recommendations depending on the aluminum alloy used in their pistons or their individual piston design. I believe all of the pistons that you’re considering are cast. IF some piston makes that you’re considering were cast and others forged, this too can affect the manufacturer’s clearance recommendation. Again, materials used and the individual heat dam design come into play. Generally, forged pistons expand more than cast pistons when the engine heats up… While the rings are not needed to fit the pistons, knowing what type of rings you are going to use... cast iron, moly... will affect the grit size used for the honing process. Again, piston ring manufacturer may affect the honing grit recommendation.



As far as piston manufacturer, I’m not sure if the Egge units are cam ground per FoMoCo original. That said, Egge makes a lot of replacement pistons that are not available anywhere else.



With the use of oversize pistons, consider spending the extra money to have the entire engine rotating assembly balanced before assembly. Even if you were not changing the cylinder bore, original factory balancing is not the best. Goggle www.eatonbalancing.com to read an interesting series of articles on engine balancing.



Others will weigh in on this, I’m sure. Hope this helps some...



Regards,


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

NoShortcuts, thank you for your thoughtful and thorough response. I will take it all to heart. This is what I like about this forum. I am familiar with John Mummerts listings, in fact I have them bookmarked. You are correct,my memory failed me, the ECK block is listed for'56 as well and the heads for '55 only. Also I read and reread (total comprehension on my part is another matter) everything that I see written by Ted Eaton, and have bookmarked most of it and have some material pinned up in my garage for easy reference.

Regarding Egge pistons, I am not sure what cam groundmeans. With respect to rings being cast iron or moly, which is preferred?

Thanks again.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Make certain to use pistons with the correct deck height to match your crank and rod combination. You cannot simply swap pistons with out using the correct rods or pistons for your 292. Cam ground means the piston is elipticaly ground to decrease piston slap, or noise.

Frank/Rebop

Bristol, In ( by Elkhart) 

Thanks Frank, I will be sure to pay attention to that.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Mark-



Frank's addressed the cam ground piston skirts. With the piston skirt not being perfectly cylindrical, piston friction is reduced to skirt thrust surfaces.



Piston rings are a changing technology with material coatings but part of the equation. Cast iron rings are 'old school', I guess, today. They were used for years in production engine and 're-ring' jobs. They seat quickly. Chrome coated rings were used to give improved durability, but were not usually used for 're-ring' jobs because a worn cylinder bore was not helpful in aiding them to 'seat' properly or in a timely manner. 'Moly' coated rings seem to be the choice for 'fresh start' re-bored and honed cylinders now. Some local race car drivers still like the iron rings because of their 'agreeability' to seating quickly in new engine builds or 'freshened' engine 'go-throughs'. Engine builders like Ted Eaton, John Mummert, Tim McMaster and others on this Forum are more experienced to advise you on this.



Regards,


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

If going to the trouble of boring and installing new pistons, then consider going with a piston that has the improved piston ring technology.  This helps both fuel mileage and performance.  Verne Schumann is in the process of stocking up with the new design low friction pistons and ring sets which are in the same weight range as the original pistons while pricing is expected to be quite reasonable.  As a rule on bore size, always go with the minimal values.  My own 272 is only 0.020” over which leaves lots of cylinder wall for future builds.  Doing a search for “Verne” on this site will bring up his contact information.

Lorena, Texas (South of Waco)

Thanks Ted and NoShortcuts, this is good information. I found the contact information for Verne Schumann. After I get the block into the machine shop and my needs are confirmed I will contact Verne and/or John Mummert.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia