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Rebuilding the Q-ship; a 1964 Harley Davidson Sportster

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  • Rebuilding heads aka valve jobs

    In this installment of the Q ship saga, we are going to talk about valve jobs. A lot of time is spent jawing on the internet about things like carbs, cams, and exhaust, but relatively little attention is paid to valve jobs. A lot of this has to do with misinformation about valve jobs and it seems an even bigger portion has to do with the cost. Most machine shops charge a minimum of $150 per head plus parts to do a true valve job – with the price rising fast if you want special work done. Once you toss in valves, springs, guides, and other hard parts – the price easily hits $250-$300 per head. That starts getting to be too much for the average biker and they find “work arounds” until they can’t do so any longer.

    The purpose of this write up is not to give you a step-by-step guide to doing your own valve jobs. To do so is to literally write a book. Instead, we are giving a 50,000 foot overview with highlights of the basic steps. There is quite a bit of skill and experience that goes into a full on valve job that is very difficult to capture in the written word – or even through photos. Long story made short – nothing beats experience when doing a valve job.

    What we aren’t going to talk about here are full on performance valve jobs where we are concerned about spring pressure, seat pressure, coil bind, rocker geometry, etc. That is another level and more than we have room for in this simple overview.

    So, why is it so expensive to get heads rebuilt and why don’t more people do their own valve jobs? The answer is simple – cost. Much like boring cylinders, a proper valve job requires a set of specialty tools. These tools are not only for the job at hand, but you may need a whole range of them to work on various types/brands of motor. As a result, it is almost never cost effective for the DIY/home mechanic to purchase these tools. And, be wary of used valve servicing tools. Unless you know for sure how they were cared for . . . you may wind up causing more grief than you prevent. Many, many heads have been seriously screwed up by shade tree wrenches beating guides in an out till “it felt right.” This is especially true of alloy heads. So, tread lightly if this is your first rodeo and consider a practice set of heads before you work on something you really can’t afford to screw up.

    Before we get to the tools, let’s define what we mean by “valve job.” For a lot of folks, a valve job is nothing more than getting the valves to seal. Easy peasy. For clarity, we are going to split this term into five stages from Zero to Four.

    Stage Zero is the baseline. This is where you simply clean the valves and “lap ‘em in” with compound. All the parts are reused – right down to springs. It is the oldest and the least effective “valve job.” Yes, it restores some seal, and leaves a ton on the table. In particular, “lapping ‘em in” tends to only truly work on the bench. Put simply, in the first seconds of operation, a valve heats up considerably. This causes its outside diameter (OD) to expand noticeably. This in turn causes the valve to ride higher on the seat – generally above that band you just spent time lapping in. So, while they seal on the bench . . . many a rider has experienced a bike that mysteriously “loses” power when hot. Usually the ring seal is blamed or a tight push rod, but often a prime culprit is a leaky valve that is fine cold . . . but cruddy hot. In short, avoid stage zero unless you have no choice on a back road in the third world. Or you hate your lawn mower. Stage Zero is sort of the high school shop class manifesto for small engines!

    Stage One is where you reuse the existing guides, but pair them with new or reground valves and freshen the valve seats. This is one of the most common valve jobs. If the guides are straight and in spec (relatively rare above 30K miles on a motorbike) then this can be an effective method. Chuck has found it is generally best to start with new valves and to grind, as opposed to cutting, the freshened seats. Our goal is only to remove enough pitting to get a good seal.

    Stage Two is where we fit new guides, valves, and cut new seats. This is a much more involved process and where skill as well as tools starts becoming important. This is the most common valve job from a professional machine shop.

    Stage Three is much like Stage Two, but we go further. The valve guide bore is honed to a mirror finish, the exact ID mic’d, and guides selected or machined for the correct interference fit. Guides are sized and then honed mirror smooth, valves are polished, and often the valve head is back cut at a 30 (and sometimes a 30 and 15 degree angle) to smooth the flow. Oversize valves may be fitted. All edges are radiused, etc. This is more of a “performance” valve job and is overkill for stock bikes on the street. Sort of like hunting rabbits with a .303. If you have a stroker . . . well, this might be where we start.

    Stage Four is Stage Three but with relieving/radius work, maybe some port work, and certainly valve lightening. This is for the all-out person . . . and like taking the space shuttle to visit California if you have a stock bike.

    To illustrate, over the coming weeks we will do two valve jobs. The first one, illustrated here, is a Stage Two job meant for a stock 900 sportster. When we do the Q ship, we will do a Stage 3 job, minus the valve back cutting.

    Before we get started, let’s talk about tools. In general, here is a list of the minimum tools you would need to do a full on valve job at home:
    1) 1-inch micrometer – preferably a Vernier mic.
    2) Miniature inside mic or ball gauges that can read .25 to .4
    3) Reams – proper valve guide reams are piloted and NOT common sizes. They also are not inexpensive. HSS for cast iron, carbide for bronze. Generally $50 each!
    4) 14/18mm thread restorer for sparkplugs
    5) 7 and 8 mm ball hones – or a sunnen honing station or a sunnen portahone driving head for valve guide mandrels. Ball or flex hones are about $20 each; a sunnen station will run you about $400 used, and then another $400 for tooling. The Portas generally are $400 used -- $600 new. Stone sets are priced by size and material. They range from $15-45 set. We won’t talk about the cost of honing oil.
    6) Intake and Exhaust pilots. You’ll need several solid pilots or a couple of expandables. Solids are usually around 25-30 bucks each, expandables are usually around $50 each!
    7) Intake and Exhaust seat cutters or a stone grinding kit. The most common cutters in the US today are Neway, though old kwik-way and Sioux valve cutters (or sometimes called valve reams) are around. Note that if they don’t have carbide blades, you won’t be getting through stellite seats. Stone grinding kits are also widely available. They tend to be pretty beat on the used market and require quite a bit of re-supply before use. About the cheapest you can get away is around $200 for cutters and around $500 for a properly equipped grinding set. All require some skill to use. Your patience determines your craftsmanship as they are HAND tools. Really big shops have dedicated machine tools for this stuff that allow even the inexperienced to get very, very good results.
    8) Dykem, Prussian blue, or sharpies for marking seats and contact patterns
    9) Concentricity gauge. This is to check the run out of your valve seat – it’s a $200 tool and not strictly necessary – but it sure helps.
    10) Brass brushes or a media blast cabinet for carbon removal
    11) Parts washer or a good bucket of cleaner
    12) Cleaning brushes
    13) Double diameter drift or fixture and arbor press for removing/installing guides
    14) Can of 220 lapping compound
    15) Vernier calipers or a steel rule capable of measuring 32nds or 64ths.
    16) Valve spring compressor – while you can disassemble without a compressor, getting things back together is a bit more challenging without one!
    17) Trays or pans to hold all the parts and keep them organized.
    18) Spring tension gauge (if you intend to reuse springs).
    19) A good 6-10 inch vise solidly mounted to the bench
    20) If you’re driving guides in and out by hand . . .a good 1.5lb peining or brass hammer
    21) If you’re a press guy – a fixture and 1 ton arbor or 10 ton hydraulic press.

    All in all – it’s a solid $600-1000 worth of tooling to equip yourself to do ONE valve job on one brand. Maybe you’ll get lucky and the tooling fits more than one of your scoots – but this is relatively uncommon.


    Speaking of tooling; let’s talk real fast about cutters and stones. Valve seat cutters are just that – a cutting tool that pilots off the guide centerline to create a seat. Some people swear by them and many swear at them. Neway is the premier maker in North America. Currently, there is a crop of India and China made “valve reams” on the market. Please don’t buy them. If you want cutters, buy Neways and be happy. With regard to stone kits – if you don’t buy a full kit – then what are you buying? The full kit consists of a motor, driver, spring holder, seat spring, a bunch of pilots, a bunch of stones in different grits/sizes, and a diamond dressing stand. They take up a box about double the size of a large hand tool box. Common names on the used market include black and decker, blue point, van norman, and Sioux. Brand new sets are quite expensive. Chuck’s favorite was/is the Black and Decker set with the old 5 pound driver motor, which was made by Blue Point. The sets prior to the 80s were GREAT and are so robust you can still buy brand new supplies as of January 2020 – a full 40 years since B&D last offered them!

    And, don't forget about Hall-Toledos . . .if you find a complete kit, consider buying it.

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    • On to the actual stage two, basic valve job.

      Step One is to disassemble the heads and inspect every part. “Reading” the valves, springs, keepers, collars, seats, and chambers will tell you much. Inspect and measure the guides. Check spring tension if you want to reuse springs. Then decide on next steps.

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      Step Two is to clean the living heck out of the heads. If you are replacing guides, make sure to get ALL the carbon and **** off the guide and the area around the guide – then scrub the head again. Clean, clean, clean.

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      • Step Three is to warm the head. Not crazy hot, just warm. Remove the guides. Some people knock them out with drifts, others like to press them in/out. Both work . . . so choose your poison.

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        Step Four is to inspect the valve guide bore. Remove deep scoring, measure it, and make sure you have a correct press fit with the new guides.

        Step Five is to lube up the new guides and insert them.

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        • Step Six is to measure your valve stems (ALL of them – don’t rely on the manufacturer for quality control!) and determine your clearance goal. Then, choose your ream and rough size the guides about .001 below your target. You can buy valve guide reams in .001 increments so there is no excuse to cheat if you’re this deep into tooling. Most importantly, do not rely on the ream for the final finish.

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          Step Seven is to hone the guide the size and for surface finish. We want a true, straight, properly sized hole that is shiny. Not a true mirror, but shiny. We want maximum contact between valve stem and guide, as well as guide to guide bore/head so that we pass heat from hot (valve) to cold (head) as fast and efficiently as possible.

          Step Eight is to insert your pilots in the fresh guide and cut new seats. Despite what Uncle Billy may have said you MUST cut seats if you replace guides. If you want to argue this point, stare in a mirror and do so. It’s folly to try and make it work. Anyways, you can literally cut them . . . or you can grind them.

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          Step Nine is to check the contact patterns and width of the seats. We adjust these with the cutters in small increments.

          Step Ten is to check valve stem protrusion to ensure we are within specs and not causing geometry problems if a seat is sunk.

          Step Eleven is to clean the heck out of the heads again. And then clean one more time.

          Step Twelve is to paint the heads.

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          Step Thirteen is to assemble the valve train and shim the spring pack if necessary.

          Step Fourteen is to pour some type of a thin liquid into the ports to check seepage. Rubbing alcohol is a good, cheap, non-destructive choice. Denatured alcohol, acetone, gasoline, and mineral spirits are also choices. In general, no seepage should occur in 30 seconds to 1 minute. A wet line or mark from capillary action after a minute is on the border line of acceptable – depending on whether your oiled the valve seats before assembly. In general, no solvent should escape the port for several minutes. If it does . . . your seal is compromised and won’t improve in service. Fix it.


          What we didn’t go over was surfacing the heads. This is something you have to determine as the mechanic. Generally, rocker gasket surfaces seem to suffer more than head gasket surfaces. Either way, if they need resurfacing – do it now and do it well. There are many ways to tackle this from the mill to large, flat belt sanders (believe it or not this is what most auto head rebuilders use), to adhering a sheet of 220 paper to a sheet of ¼ or 3/8 plate glass and slowly working the head. Some guys will even spend an evening lapping the head to the cylinder to avoid the use of any head gasket. Buck dancers choice – but get a good seal.

          Again, this is a 50,000 foot overview of a very basic valve job. Some shops go to even more steps.


          A few more tips about painting heads. On an ironhead sportster, the heads get HOT and hold that heat for a long time. It is imperative we have good adhesion for paint to actually stay on. Harley still sells high-heat silver paint (early Sportsters painted their cylinders and heads silver/aluminum) so you can use a genuine MOCO product if that makes you happy. Chuck tends to use VHT engine enamel. Tip number one is to make sure the heads are clean as clean can be. Do what it takes to get the fins clean and rust/oil free. Next, warm the heads to around 80-100 degrees, wash them again in near boiling water. The heat will drive off the moisture and you’ll get a quick flash of surface rust. Wash the surface rust off in acetone. It will slip right off with a brush (remember, we are doing these things within an hour – not over days). Let that dry and shake up your rattle can. Once the paint is shook up, put it in some warm water for 10 minutes. Shake it again, and apply two very, very thin coats. Let it dry an hour or so, and bake the heads in the oven at 300 degrees Fahrenheit for 90-120 minutes. When the beeper goes off; turn off the heat and leave the heads overnight. In the morning, viola, well coated heads.

          All in all, it takes between 60-120 minutes to do a valve job on an average head depending on which stage you choose. When you are paying for a valve job, you’re paying not just for this labor but also for all the tooling.

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          • trap door

            Most ironhead owners are blissfully unaware that there were multiple changes to the transmission trap door over the years -- plus a very large number of aftermarket offerings. What makes the ironhead such a unique bike is that HD kept developing it and there are many small running changes to parts. This is particularly true of 900 sportsters -- which are a very different beast than a later 1000 cc ironhead. approaching the two models the same way can drive you NUTS.

            Anyways, the doors were improved in response to real world issues. Aftermarket doors are about one thing: horsepower. As you increase the power, things break. In the transmission, the two weakest points are the case countershaft boss and the transmission trap door countershaft boss. So, they get beefed up. But, beef one up much more than the other --- and something suffers.

            The point here is to show two "normal" HD doors, and early and a late one, and a typical aftermarket performance door.

            In this case, the door on the left is what would have come with the 64CH. Notice the countershaft boss is in a Keyhole shaped protrusion. On the middle, later door, the countershaft is better supported. If you look at the photos you'll also see many subtle changes throughout the door to make it stronger.

            The door on the right is a cast iron TROCK door. It is very strong and VERY heavy. Other aftermarket doors were offered by sputhe, strociek, vulcan, etc. In other words, there's a lot of these things out there.

            For a normal ironhead owner, a stock door is fine. Once you get into big inch bikes . . . you might want to flip your lid. Buck dancers choice.

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            • A Rolling Chassis!

              Saturday dawned bright, so we got down to working on the front hub (skimming friction surface, installing new bearings, and arcing brake shoes) and then lacing it up to a new rim. The front rim proved a bit more of a fight than the rear to true -- but nothing horrendous. Spokes and nipples came from Buchannans and fit very well. The rim didn't even require any of the nipple holes to be opened up.

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              With that done, we reassembled the front forks, mounted a tire, and the 64 CH was able to roll on its own for the first time in probably 25 or more years.

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              • A few more shots of the roller:

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                And, we got the below photo in the "email" from our technical advisor, Dr. Dick. The "big" crate are the machined engine cases for the Q ship and the "small" crate is a pair of 1972 heads we will be using. There's a third crate as well -- with a C ratio transmission set in it :-) Gotta love palindrome days.

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                So, we should be able to get down to the motor work in a couple of weeks. Much of the tough work is already done and what we really need to do to the cases are as follows:
                1) Connecting Rod Clearance for the longer stroke
                2) Installing a new Timken in the left case
                3) Installing new torringtons in the right case
                4) Cleaning
                5) Lower end assembly

                Then we can finally install the motor bottom end in the chassis and move on to building the top end and transmission. The reason for doing it this way is that the sportster frame makes an ideal engine stand. Not to mention, it is far easier to install just the cases and crank assembly in the chassis by yourself. Sure, you can grin and bear it to get it in or even lay the frame over the motor -- but once you discover the joy of building the motor in frame -- it's hard not to do it this way if you have the opportunity.

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                • Building a bottom end for the Q ship

                  The engine cases arrived from Dr. Dick's shop just before the weekend. That gave us plenty of time to get them squared away.

                  Long story made short, Dr. Dick did a wonderful job on boring the cases and fixing some of the abuse rendered over the past 54 years.

                  What we had to do was helicoil the motor mount threads because someone in the past shoved the wrong thread pitch in there. You can often do this "once" but the moment you pull the bolt the first time the screwed up threads are toast. That was clearly the case here.

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                  So, we got down to business and sorted out the threads.

                  We also went over the cases with a comb, noting anything that needed attention.

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                  With that done, we turned our attention to clearance for the stroker crank. Though we are using a 4-5/8 stroke -- we clearanced the cases for up to a 5 inch stroke incase we wanted to go bigger in the future.

                  We then mock up a half motor to make sure there is plenty of clearance. The minimum is .060 and really .125 if you can swing it. We had plenty of clearance, but did wind up notching the piston to avoid them touching at the bottom of the stroke.

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                  • We then turned our attention to the half-a$$ed polish job that was done to about 1/3rd of the cases. Why a previous owner gave up after sanding 1/3rd of the cases we'll never know . . . but it looked weird.

                    One of our goals here is to do no permanent damage so that a future person can consider restoring vs. rebuilding the bike. This meant that finishing the polishing was out of the question. Instead, we focused on restoring it to an "acceptable" level.

                    In this case, acceptable means you won't necessarily notice we restored the surface texture until you get within about 12 inches. To really make the repair disappear we would have needed to media blast the cases. At this stage, the cases are VERY clean and we did not want to introduce any grit for the sake of cosmetics. So, we went with a good enough restoration of the surface finish. If you truly desire a better finish . . .then you need to get more serious.

                    There are multiple ways to restore a surface, from steel shot in a cabinet to pressing in oxide sheets to carbide burrs and needle guns. One of Chuck's favorite weapons is a Hastings Pneumatic Peining Hammer.

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                    This is a nearly 100 year old tool and works flawlessly. Basically it allows you to dimple the living heck out of a surface and was originally designed for expanding pistons in their bore to take up clearance (seriously). When you use it on cast alloy, if you overlap well and take your time you can make the surface look like a rough casting. Treatment with acid and media then evens it all out and you have to scrutinize to find out what happened.

                    Like I said earlier, we only went for the peining part . . .

                    here's where we started

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                    half way through

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                    and done, fully cleaned, and way, way brighter than the cases will be in a year. Sadly, they are so bright right now the peining stands out in my shop. In the real world it won't be this noticeable.

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                    The cases then got triple cleaned -- parts washer, hot soap and water, baking at 300 degrees for an hour, and a final wipe down with acetone. The interior got a coating of glyptal and baked again for 2.5 hours at 300 degrees to set the coating

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                    • With the cases ready for assembly it was time to get prepped for pressing in new bearings. We have a new Timken race to insert in the left case, 4 torringtons in the right case, and the countershaft bearing in the right case.

                      One of the biggest mistakes people make is beating bearings in and out of cold alloy. Please heat your alloy to at least 200 degrees. Despite what you may have heard, it is much more important to heat the cases to at least 200 degrees (250 if you can handle it without burning yourself) than it is to put any bearing in the freezer. If you've seen a freezer on an assembly line; I'd like to see the picture. Put simply, alloy cases expand way more than steel inserts contract. Whether your race is at 40 degrees shop temperature or 20 degrees coming out of the freezer is immaterial compared to room temperature vs. hot cases.

                      So, the first thing we have to do with inserting the timken is to place the retaining ring in the bottom of the left case half:

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                      and inserted

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                      Case half goes back in the oven for 25 minutes at 250 degrees.

                      We then used the time to prep our area. Blocks of wood to support the cases on the press bed and shop towels over that to keep junk away.

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                      Immediatly next to the press we laid out the timken race, our press tool, which is simply an exact fitting 36MM socket, and a cuppa to keep us company and patient.

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                      Then, it's a matter of dropping in the bearing and pressing it in until it bottoms firmly against the ring. You want it firmly pressed, but not so hard you break the alloy.

                      Then, we press in the other bearings in the right case half and set everything aside whilst we clean up our assembly area.

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                      • When you are building a bottom end - cleanliness, patience, and organization are the three rules you need to follow. If you do - you will be very happy. In this case, even though we've done this before -- we always have the factory shop manual and the parts book open to relevant pages. They are laid out behind Chuck in the following photos.

                        We then take the time to vacuum the bench top, wipe it down, and lay out an assembly surface. I like to use plain brown paper under a layer of clean, fresh cardstock. The cardstock allows me to write notes directly on my work surface and helps with organization.

                        In the following photos we have the hardware and parts staged on the left, a big area to work in the middle, and our case sealant on the right.

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                        The final think we like to do is set up our "heating station." Several parts in the bottom end are "press fit" parts. There are special tools to accomplish this work - though an even easier method is to use our old friend: heat. Specifically, we like to warm up bearings and press fit gears in oil. Chuck keeps an old sauce pan and hot plate in the shop just for this purpose. By heating bearings and gears to roughly 300 degrees, they simply slip on without fight.

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                        • Once our bearings came up to temperature, we were ready to get moving. We unwrapped the crank from its plastic protection and fished one of the bearings out of the oil bath. It slipped on without any fuss. Make sure it is shouldered and then onwards we go.

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                          Spacer ring gets dropped on then the left case half. Fish out the other bearing drop it over the shaft and it will fall mostly into the place.

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                          Grab a press sleeve and the sprocket nut and whilst everything is still warm -- finish drawing the crank into the left case half.

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                          It's all down hill from here. Next up is the pinion bearing, applying a layer of yamabond to the case halves, and assembling everything (don't forget the rear motor mount!)

                          With the case hard ware snugged down, it's time to build the oil pump. We got lucky and had two modified pumps to work with. Modified in the sense previous mechanics had retimed them to XLR specs. We checked this timing and indeed, they were within 5 degrees of the XLR specs. Yippee. So, in goes the pump.

                          About now, someone asks how we got the pinion gear on. The spiral oil pump drive gear should be a slip fit on the pinion shaft. If it isn't -- find out why. The pinion is always tight on these bikes. But, heat is again our friend. Grab a small propane torch if you're done smelling oil and heat the gear to a very light straw color. It will slip right on the shaft and you best be prepared to position it before it shrinks down. It's often better to come up a bit short and draw the gear down then to try and pull it back to the right depth.

                          With that done, it's time to install the cams (Sifton -/- in this case)

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                          • Then, we install the timing cover and the bottom end is all but done.

                            We still have to install the tappet guide blocks, but that is a pretty fast exercise.

                            With the bottom end done, take the time to stuff rags in every opening and to tape over anything else. The goal is to keep EVERYTHING out of the clean, fresh motor.

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                            The motor will then be installed in the frame and we will finish building it there. It's a lot easier to install a bottom end by yourself than a full motor/transmission!

                            There's much more to this than these photos and descriptions suggest. But, this gives you a basic overview . . .

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                            • I've been advocating this modification on the side stand tab for years. I've seen a lot of broken cases and experienced one catastrophe myself. I weld the tab to the peg mount even on complete restorations. If I ever lose a half point for it, so be it.

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                              • Wow chuck, what talent, i need to get on the stick and try to get my 57 65 and 66 projects going, sure wish i had the talent and expertise you have, plus i could use a few extra yrs, i am now 73 and have been into the early ironheads for about 10 yrs, i currently have 9 early ironheads, they are a pleasure to ride, my favorites to ride long distance are my 61 xlh and my 77 xlt, keep the good work going, really appreicate you taking the time to do this, larry

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