11A Engine Rebuild - Fairbanks, Alaska

bluetaxi · November 26, 2012

I am just starting an engine rebuild on my early model Franklin 11A. This car was one of the first 11A’s produced – one with the Raulang body (Rausch & Lang). These early cars had “protype” steel bodies made outside Franklin’s normal chain of delivery so that marketing could fill the supply chain with the new “faux radiator” style before Wilcox found out about the restyle project. This car is Serial 151731 – one of the first 250 made and I believe the fourth oldest surviving 11A. The car went across the block at the Kruse Auction in South Bend in I believe ’98 or ’99 , reportedly out of a museum collection and was bought by Harry Jenkins of Atlanta. I received the car in a trade a few years later. In the winter of 2004-5, I replaced the frame (the original was rotten behind the front wheel wells) with a new one of laminated ash – following the club blueprints (it fit perfectly, right down to the drilling and alignment of the bolt holes). The engine is tired, smokes a lot, carboned up, and full of sludge – time to tear it down and see what I have and rejuvenate it. I pulled the engine today, and am starting that exploratory journey. I will post occasionally to keep everyone up to date on progress. Here are a couple of pictures.

November 26, 2012

Looking forward to hearing about your engine overhaul.

odyssey · November 26, 2012

Keep us posted Rick. Let me know if I can help - I've done a few of these.... They are beautifully designed and constructed and are great runners.

Tom Rasmussen

trimacar · November 26, 2012

You probably know this, but thought I'd mention, having been involved with a couple of Franklins in my past....engine rebuild on a Franklin is different than a water cooled engine...set up very loose tolerances for rings and pistons, the car runs about 100 degrees hotter than a water cooled car, and the resultant expansion has to be accounted for....and a cold Franklin engine will make a little noise until it warms up.

As I said, you probably are already aware of this, my son calls me Captain Obvious, Defender of the Already Known!!...............

bluetaxi · November 27, 2012

Got over to the garage for a couple hours again today (11/26/12). For those interested, the engine number is E99958. Pulled the fan with no problem. Curiosity led me to pull the #1 cylinder jug, and I'm starting to run into mysteries. I started to tear down the engine because it was badly carboned up, full of sludge, ran rich, and acted tired. I can tell the engine has been apart before (no surprise after 88 years) because of the number of hand cut gaskets, etc. I expected to find worn cylinder walls and worn or broken rings - but they look new. I'll get out the digital mic tomorrow, but with inside caliper and steel rule they appear to be 3.25" and the rings show no wear (and the oil ring looks to be of modern design). I went to the parts book and drawing file to look up a print of the piston (should be drawing 84489) to see if it was original style or a replacement, but the Franklin Club drawings don't appear to include any of the 8xxxx series. I find it hard to believe that someone would have done top end work including rods, pistons, and at least honing cylinders without at least cleaning up the mess the rest of the engine is in, but you never know.

I'll probably box up the carb this week to send it to Randy Fusco. I know it is a major part of the problem with the car running rich because I could even remove the idle adjust screw all the way and it still ran too rich... But the engine will at least get disassembled, cleaned up right, bearings checked, and re-gasketed.

bluetaxi · November 27, 2012

(11/27/12) It appears that cylinder jugs have been bored .030 or .035 oversize. Pulled cylinder jugs 1, 5 and 6 and in the wear area they measure 3.285, 3.281, and 3.286. I'm not sure what piston diameter is supposed to be but they measure at the face 3.257, 3.256 and 3.256 respectively. The bottom oil ring is of the 1930 Indiana Piston Ring design shown on drawing 32479. There is a little cylinder wall marking from the piston skirt, but not the extent that it can even be felt with a finger. Next trip to the garage, I guess I should pop a ring off and see what diameter it measures with the proper joint gap (.018 I think). I'm not sure why this car smokes this much with what looks like good straight re-bored cylinders and like-new rings.

Also pulled the transmission from the engine. Only issue here is a worn or damaged thrust bearing retaining nut; the thrust bearing appears good, but I'll have to get the nut off to open the clutch. I assume I need to pullout and turn the locking pin before I open the clutch cover? (little pin under the 116 numbers on the right of the plate in the picture).

odyssey · November 28, 2012

Hi Rick -

Measure the pistons at the bottom of the skirt on the high-point of the cam, perpendicular to the pin. I can't see the skirt design on the thrust side - does it have a full slot that goes all the way down through the skirt, or does the slot end at a round hole (called a T-Slot)? Also, once you find the high-point of the piston, at the bottom of the skirt, measure up, along the high spot on the cam, to just under the oil ring groove. This taper is important when calculating proper clearance for any piston design.

0.018" for a ring gap is o.k., just not less than 0.015 for the top ring, a bit less for the 2nd is o.k. I never like them too wide, but many feel wider is no issue until you get WAY wide. They do carbon up eventually. Too tight and you would have known it as they would have stuck already.

A chewed up throwout nut is fairly common from mechanics not having the proper tool to remove it. You leave that nut in place to remove the clutch. The clutch will come off by simply removing the cover bolts - there is not a ton of tension. You can pull two bolts and insert two longer ones to help.

The locking pin is for adjusting the clutch - leave it and the adjustment in place so you don't have to re-adjust if you re-use the pressure plate.

Tom

bluetaxi · November 29, 2012

Tom –

The high spot in the diameter of the pistons is generally at the spot perpendicular to the wrist pin, and is about +.010” proud from the earlier measurements I gave. On the three pistons (#1, #5 and #6), it measures 3.285, 3.275, and 3.281 respectively. There appears to be NO measurable taper as measured at that spot on the diameter from the top just below the oil ring to the edge of the skirt. The slot design is a very slightly slanted “T” with a fairly wide cut across under the oil ring with the two ends of the “T” ending in a hole (see picture). There is scoring that can be both seen and felt on either side of the piston, and the scoring is of uniform width down the side from the top to the bottom, which would confirm no taper. This scoring is mirrored on the cylinder wall, but the wall is harder and thus there is only the visual evidence of the rubbing; nothing that can be felt with a finger.

The diameter of top ring, when fully compressed to no gap, is less than the diameter of the piston (3.255). When removed the ring is not fully flat and slightly out of round, but measures about 3.25 when fully compressed to no gap. The width of the ring is .143”. The diameter of the piston inside the top ring groove is 2.890. If my calculations are right, the gap in the ring when against the cylinder wall at 3.285” would most likely be .110” (which at ~1/8” seems about right with three seal rings and an oil ring) and could be no more than .342”.

Therefore, it seems to me that the ring size is OK. This is not what I expected – again going back to the way this engine smokes when running. It also sounds like the replacement pistons in it were not perfect, but may be “good enough”. Your wisdom?

odyssey · November 29, 2012

Hi Rick -

Your numbers don't quite add up comparing your current piston measurements to the cylinder measurements. Maybe I mixed up 1, 5 and 6. Can you try again?

Best way to check ring gap is to insert the ring into the bore, square it up with a piston and measure the gap. ~0.110" would not be good at all - I'm sure they are tighter than that.

You mentioned smoking, but not what kind of smoke and under what circumstances?

tom

bluetaxi · December 2, 2012

I got tangled up in my math trying to calculate out circumferences, etc. Measured as you suggested, the gap on cylinder #6 is .038".

Smoke is good old blue smoke, and it smokes pretty continuously when the engine is running - not just when load is changed on the engine with shifting, etc. Tailpipe gets a black oily residue. It is better when the engine is hot, but it still produces blue haze.

odyssey · December 2, 2012

Hmmm. The rings look scored on #6 in the photo - can you feel scoring on them?

Can you tell from piston tops if one cylinder has been smoking worse than others by the amount of carbon on the head, spark plug and cylinder ports?

0.038 gap is too much. You might need to check all the ring gaps, especially the oil ring gaps. If you have wide gaps and scored rings, I would expect smoking to be possible.

Such a wide ring gap might also be from someone installing a smaller ring in a larger bore. At 3-1/4" bore, a ring 0.010 small would have a gap 0.030 bigger. And the wrong sized ring does not fit a bore with even tension, causing additional ring problems.

Maybe measuring all rings would be a good idea.

Then pistons and bore sizes would help you determine what options you have.

Tom

bluetaxi · January 21, 2013

Update from the past month:

1. Have the engine disassembled and major sludge cleaned out (had a lot of both the slimy type and the coffee ground type, some in strings).

2. The engine has been worked on before. The last guy autographed it - a Carl Basey in 1975 in Lakeland, Fla.

3. Cylinders are all bored about 35 thousandths over - they vary from 3.275" to 3.285, and while the sides are glazed there is no measurable taper or wear.

4. Pistons are marked as being .040 over, and measure 3.253 to 3.255 at the face and about 3.282 at the skirt across from the pin.

5. I have pulled rings from cylinders #1 and #4. In cylinder #1 with a cylinder diameter of 3.275 the ring gap from first to fourth (oil) ring was .022, .022, .022, .051. In cylinder #4 with a cylinder diameter of 3.285 the ring gap from first to fourth (oil) ring was .028, .025, .026, and the oil ring at .050.

6. Valve and valve guides were replaced. The valves are 1 1/2" diameter, but have a .340 shaft diameter and faces are flat. Guides are matched in diameter and have very little wear. Valve length varies, as it appears that stock valves for some other engine were cut to length and the keeper hole drilled. It does however look like the keeper hole is the correct distance from the valve face.

7. Valve seats and valves are pretty badly carboned up, and it looks like the valves were not properly lapped in, or else have built up a lot of carbon. Exhaust valves have a lot of carbon as expected, but the intake valves (especially on #1) have a lot of soft deposit on the back of the valve and in the intake port.

8. It looks like Basey did not replace the springs. They vary in height, and it appears that he added spacers (in one case as many as 3) to try and compensate. Doing a rough check, they seem weak - on the one I checked with a scale I barely got 20# at the specified 1 3/4" height. This probably explains why the car would backfire at higher speeds... Is there anyone making these springs?

9. Last issue is that it appeared as if the cam shaft had never been pulled from the engine based on several points - the original brass plug at the rear and a totally corroded in place pin at the front (had to drill it out of the aluminum block). The problem is some severe pitting on the lobes - deep enough that it is beyond the hardening and the camshaft probably cannot be ground. The good news is that all the valve lifter faces are clean and it looks like they have all been free to rotate.

Comments and suggestions welcomed!

RansomEli · February 10, 2013

Thanks for sharing photos and information about your rebuild. It's very useful to have a pictorial history of how to detect and fix problems.

bluetaxi · February 20, 2013

UPDATE:

1. Once I got valve seats cleaned up and valves examined, it was very apparent that valves were not seating true in the seats. Found someone who could reface the valve seats properly in line with the valve guides. The valve seats were all out of square alignment with the guides, meaning that when valve guides were last replaced the shop that did the work apparently did not have the equipment with a pilot to keep the refacing stone in alignment with the guide. Not many shops can do this on a jug cylinder - I finally found a mechanic at a local airplane engine rebuilder who had the proper Souix grinder equipment at his home and did them for me.

2. Ring gaps are all way too high - will replace all the rings with new cast rings of the proper 40 over size in order to get the gaps down into the .012 - .015 range instead of their upper 20's as this set reads. Have another shop honing the cylinders and confirming diameter and taper for me. When diameter are confirmed I will look up the Hastings spec rings and give Egge a call to order them. When the cylinders are honed, I will take them to have them hot tank cleaned - to see if I can clean up the copper fins so they look pretty!

3. Found a set of 12 springs that are at 33# at 1 3/4" inches. This is slightly high, but should be much better than the set that was in there that was way low (18#-21#). I will leave out the multitude of extra spring washers that I found installed, and go back to one spring washer per valve. This extra pressure should avoid the apparent float that I was experiencing.

4. Cleaned up the camshaft and measured it. It measures as new, but has pitting. Bearings all look great. Decided not to address the pitting. Have now re-installed it and it turns freely (can tighten the bearing cap set screws until it feels resistance to turning and then back off each just slightly and set the lock nut on the set screws). Found a proper replacement 2" spring brass bore plug.

5. Crankshaft measures as new, but has some slight pitting. Bearings all look great and like the cam, I will not address the pitting. With the crankcase all clean, next step is to set the bearings to proper clearances with plastigage.

6. Have asked Jeff Hasslen to make up a full set of gaskets for me, and when they arrive I will be able to re-assemble the engine. He will also sell me a new timing chain, as the existing shows wear.

7. Randy Fusco should be returning a rebuilt carburator to me soon, and with the valve job now done right and new rings, I have expectations of much better performance from this Franklin.

bluetaxi · February 28, 2013

THE ADVENTURE CONTINUES....

Blow up the picture big size on your computer and you will see the crack at the top of the #1 Cylinder. It starts at the top arrow point and extends down through the (reground) valve seat and to the lower, 4th, arrow point which is just below where the top ring of the piston travels. DOES ANYONE EITHER HAVE A CYLINDER JUG FOR AN 11A available, or does anyone have any advice on welding up and re-sleeving a Franklin cylinder?

odyssey · March 2, 2013

THE ADVENTURE CONTINUES....[ATTACH=CONFIG]180440[/ATTACH]
Blow up the picture big size on your computer and you will see the crack at the top of the #1 Cylinder. It starts at the top arrow point and extends down through the (reground) valve seat and to the lower, 4th, arrow point which is just below where the top ring of the piston travels. DOES ANYONE EITHER HAVE A CYLINDER JUG FOR AN 11A available, or does anyone have any advice on welding up and re-sleeving a Franklin cylinder?

Some cracks in Franklin cylinders are more readily repaired than others - yours, unfortunately is one is one of the others!

The trick is to get to each end of the crack. not a problem at the bottom of the crack, but wrapping into the valve seat means welding through the seat and re-machining it for a new seat, which is pretty tough in the blind hole. On ealier cylinders that are unobtainable, weld repairs have to be made. Here's one that we did recently on a 1916 Series 8 cylinder - simplified in that it did not go into a valve seat. We sleeved the cylinder as well since it was worn and already +0.060 - no room to bore larger. The car is running well today.

(Outside of cylinder - crack visible across top)

(crack hilighted with dye)

(Weld completed after crack was vee'd out through the cylinder wall for full penetration) We made a new section of cooling fin and attached it to the cylinder wall by milling a shallow groove in the new weld.

I am hoping these repairs hold up well. The alternative is to cast new cylinders, which brings a whole new set of potential problems (and costs!)

You should be able to find a suitable cylinder for the Series 11 - PM sent.

Tom

bluetaxi · March 21, 2013

:):)Wow! Found One. Thanks to Jeff who talked to Robert - who has a cylinder - who will send it to Chickasha with Dean to give it Willy to bring it to Fairbanks! Thanks to everyone - there are really wonderful folks in the Franklin Club.

:)

11A Engine Rebuild - Fairbanks, Alaska

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