# Major Seal 30cc Build



## Basil (Nov 6, 2020)

Early days on the Hemingway kits Major Seal 30cc designed by Edgar Westbury. I've been involved in many machining projects over the years and have a background also in boat building but this is my first time building an entire engine from pretty much scratch. Being mostly self taught this might not be a totally conventional way of building. I'll be learning along the way! Super glue jiggings parts together? I must say it worked out well though! Onwards and upwards!


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## Basil (Jan 28, 2021)

Back on the Seal Major build now I'm finished with the tool post grinder. I have the liners pretty much done just honing to final size. Piston clearance is not mentioned in the plans. Advice would be much appreciated on this. The bore size is 13/16". Cast Iron liners with pistons machined out of aluminum (Dural) bar stock. On the racing Zenoah's (bigger piston at 34mm) they run 1 to 2 thou." diameter reduction above the ring in the combustion zone.


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## Basil (Feb 9, 2021)

Finally done with the crankshaft after I don't know how many hours! Happy with the result though and that's the main thing. Learnt lots along the way also.
Now to the other 3 pistons now I've got that procedure understood.


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## Vietti (Feb 9, 2021)

I'd be lost without superglue to match drill etc.  Harbor Freight works just fine.  Consider some instant set spray and release.


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## Basil (Feb 19, 2021)

Moving onto the cam! The firing order on the plans is 1243. This is an unusual firing order for a 4 cylinder engine, most everything I've seen is 1342. As I've mentioned before this is going to be installed in a boat and I have decide to have the flywheel at the front which will have a gear and one way bearing for an electric start. All of this messes with the cam lobe positioning not to mention the 1 exhaust, 2 intakes, 1 exhaust and a repeat of the same for port configuration.
To clear this up in my head I decided to CAD it up. I have been 3D printing for about a year now with an Epax X1. CAD is a fantastic tool but I find there is no substitute for holding something in your hand and giving it a good lookover. I machined a flywheel up for another boat a while ago, drew something up in CAD and thought "that should do it". Decided first to 3D print before cutting metal. When in hand it was obvious it was too small for the engine.
Very happy to have something to refer to when getting ready to grind the next set of lobes. I absolutely detest throwing parts in the bin
Some pictures of my 3D resin printing.
Onwards and upwards!


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## Basil (Feb 19, 2021)

Back to the drawing board on the cam. As a few have noted the lifter face on the Seal Major engine is not really large enough to be ideal. If I incorporate a mushroom head on the lifter, material would need to be machined away at the bottom portion of the lifter bores which would leave them quite short. It looks like changing the base circle is the best way to go.  Is there a reason why I shouldn't do this? Thanks


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## Eccentric (Feb 19, 2021)

This is a copy of another Westbury sleeve.  It is interesting that he calls for a .001" interference fit to the block both at the top of the sleeve and the bottom, but the lower hole in the block is .010" smaller diameter.  For ease of installation I guess.

This is also from Westbury: Aluminium alloy pistons should have about 3 thou clearance at the skirt, increasing above the gudgeon pin by tapering, or easy steps, to 6 thou. The inside of the skirt should be machined as far as the gudgeon pin bosses will allow. 

I simply use .005" clearance between the piston and sleeve.


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## Eccentric (Feb 19, 2021)

Your crankshaft looks great.  How do you insure the tool post grinding wheel is perfectly flat and perfectly aligned side to side?


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## Steamchick (Feb 20, 2021)

Eccentric said:


> View attachment 123258
> 
> This is a copy of another Westbury sleeve.  It is interesting that he calls for a .001" interference fit to the block both at the top of the sleeve and the bottom, but the lower hole in the block is .010" smaller diameter.  For ease of installation I guess.
> 
> ...


Curious comment about top and bottom fits of the cylinder liner being different... But when running, the temperature is different. So the sizes are probably optimised by Westbury based on his calculations for fit - and finished size when at running temperature. 
Similarly Pistons: As the crown gets "flippin hot" with combustion heat and expands much more than below the ring pack, it is NORMAL PRACTICE in production engines (like your car) to have appropriate clearance WHEN at its HOTTEST, so the piston does not touch the bore above the top ring, or between rings: Only below the bottom ring (about where the gudgeon pin bosses start) do you get the size for the sliding fit of piston to bore: The skirt does ALL the alignment of the piston - even though in the latest car engines it is more of a "jock-flap" than a skirt!
Just my guesswork... but may be of interest?
Cheers!
K2


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## Basil (Feb 20, 2021)

Eccentric said:


> Your crankshaft looks great.  How do you insure the tool post grinding wheel is perfectly flat and perfectly aligned side to side?


Thank you. I put a faceplate on the spindle and used a parallel against the grinding wheel as a start then put a dressing stone fixture in the spindle and dressed the wheel as needed. Every time the grinder gets installed the wheel will need dressing to get the best results.


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## Steamchick (Feb 20, 2021)

Hi, just spotted this. Remembering the dedicated crankshaft grinder when I was a lad (part-time apprentice?)... the weekly maintenance included adjusting "the slides and gibs". Actually, there were nor slides and gibs as the stone was on a set of lever mounts on bearings, but the dial knobviously that turned the thread to introduce the stone to the wheel needed the covers removing and cleaning, to try and reduce the wear of the fine thread and split nut. It was calibrated in half-thou as Oi recall, so a very fine thread to introduce the "cut".  
I assume in this explanation the grindstone is set in place of the toolpost so the slack must be removed from the cross slide nut, and gibs set as close and even as possible without binding. Also the main carraige saddle gibs should be serviced, and lubricated. Do cover all surfaces with cling film, paper and masking tape etc. To keep the grinding dust from wearing out all the slide, etc. Use dust extraction, unless you are using a wet  system (the dedicated crank grinder I used was oil cooled at the stone which was about 18 inches diameter!). You must use a tailstock centre to support the shaft, and the parallel  journals were achieved as a combination of careful stone dressing before the "cut" and the traverse along the length of the journal. The corners of the stone had a radius to minimise stress ring at the ends of the ground surface of the journal, so journals on your crank should ensure adequate length for the radiused corners the stone will give you, beyond the journal bearing surface.
Enjoy!
K2


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## Basil (Feb 20, 2021)

I've brought the base circle down to 3/8"to allow clearance for the enlarged lifter head which will be 1/16"thick on the face. The flank radius is 3/4" with a nose radius of 0.0625 on the exhaust and 0.0235 on the intake. Crank duration is 228 intake and 234 exhaust which I feel is a little on the low side. Might work on this further. I have a OS 30 I will use for comparison.  Fusion 360 is amazing for mocking up these assemblies.


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## Basil (Jul 31, 2021)

My second go at the camshaft. The first one was fine until case hardening which for some reason ruined it. This one is machined from EN24T which I am going to run as is with hardened lifters and see how it holds up over time. Thank you for everyone's advise on different materials and case hardening facilities. I'm going to give this EN24T a go first. Spring pressure is very light and I have widened the lobes by nearly 50%. With a good oil and break in  It with be a learning experience anyway. I find it very helpful to color in the cuts also referencing the intake and exhaust lobes. The EN 24T is tough on my cutters and seems not easy to get a nice finish. I plan to remove most of the material with by regular carbide cutters and finish up with my tool post grinder.


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## Weldsol (Aug 2, 2021)

Hi Basil
Glad you got your cam sorted, I know it can hard to decide which process will be the best in the long run after all the effort of producing the cam.
Paul


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## Basil (Aug 2, 2021)

Absolutely Paul. This has been the most complicated part so far and I must confess I was a little gun shy by the thought of having to bin another. I will get the engine running and see how the cam holds up. Had a good day yesterday and got the new cam finished except for some smoothing and polishing. The rods are almost complete also with the EN24T rod bolts. Pistons next.


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## Weldsol (Aug 3, 2021)

Hi Basil
Re piston to bore clearance I can only go from ETW's Sealion which states the on the drawing (see PDF)
Also in his writings he stated "low-expansion alloy" and if a different alloy is used then the clearance may have to be opened up ,but "Do not make the clearances larger than necessary as this could lead to oiling up"
Hope this helps

Paul


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## Basil (Aug 22, 2021)

Thanks Paul,  2 thou for from the bottom of the skirt to just below the second ring and 3 between rings, 4 above.   looking to reduce piston rock to a minimum. I assembled with no rings to check for clearances and any tight spots. Not bad but room for improvement me thinks. I decked the block an extra 15 thou and that puts the pistons 3 thou in the hole after slight piston top dressing to bring them spot on.  Time to make the valves.


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## Weldsol (Aug 23, 2021)

Hi Basil
Looking good like the vid, 
One question did you get your drawings from Hemingway's ? as I have had a couple of issues on dimensions such as gear dimensions on the skew gear for the pumps the gear supplied is a bigger OD than on the drawing which has a knock on effect with other dim's, also the distributor cap is smaller (by almost 3mm) again effects all the sizes inside 
Paul


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## Basil (Aug 24, 2021)

Yes Paul from Hemingway's. I have not got to that part yet but will check it out. I plan to use the engine in a boat so was thinking of a multi coil setup and do away with the distributor for reliability. With the high prop shaft/ engine angle I plan to run a oil pump off the front of the cam to flood the oil trough.
Most of the valves finished. Got a stem slightly undersize and have to order some more material.
I decided to use my digital burette and check what the compression is. Bit of a shocker! In the ball park of 4.3: 1. 
I was expecting at around 6: 1. Keeping in mind no center main bearing on this engine.
What are most of these little engines running for compression?
Cheers


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## Charles Lamont (Aug 24, 2021)

That sort of compression ratio is typical of a Westbury designed side-valve engine.


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## Weldsol (Aug 27, 2021)

Hi Basil if you are using a head gasket it will very slightly under that reading
You could overcome that by lapping the block and head
Also you could skim the head but if you do check valve to head clearance

Paul


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## Basil (Aug 28, 2021)

I plan to use gasket eliminator for the joint. I’ve used this Locktite product before with good success although not on anything this small. The water feed to the head will be external. I’ll do a plastiscene check on valve to head interference Paul. Thanks


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## gadabout (Aug 28, 2021)

Basil said:


> I plan to use gasket eliminator for the joint. I’ve used this Locktite product before with good success although not on anything this small. The water feed to the head will be external. I’ll do a plastiscene check on valve to head interference Paul. Thanks


That’s all the compression my Seal 15cc has, I also used loctite gasket eliminator, works well!
cheers
Mark


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## Charles Lamont (Aug 30, 2021)

I would suggest Stag Wellseal. It does not harden. I have used it on my Seagull, where there is less than 1/8" between combustion chamber and water passage. The mating faces are lapped flat.


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## Basil (Sep 16, 2021)

Thank you Charles, I have started using Wellseal on some large engines I work on and really like it.   
Work progressing on the Seal Major engine. I decided to improve upon the manifold to block fixing by relocating some of these bolts so as they do not run into the head studs. I had already drilled the manifold and cover plate so had to plug these and counter bore the cover and make raised spacers to retain the "as cast" cover appearance.
Next was the lifter cover where the retaining bolts screw into the block water jacket. I decided to make threaded stand offs that were high temp. epoxied in place and machined flush with the mounting surface to stop any deforming when tightened the delicate cover. 
 As I mention previously this engine will be installed in a boat and at the same angle as the prop shaft ( about 9-10 deg) The timing cover being at the lower end. I purchased a seal 10mm ID x 14mm OD. 3 mm thick and made a hardened and ground spacer for the seal to run on. 
Also incorporating a bronze bushing to hopefully help support the crankshaft. 
Deciding against drilling the block deck for water passages to feed the head, I constructed an outside water link manifold.
Dipstick was next on the list and I really enjoyed making this little jem.
This evenings job was a couple of water flanges for the block and head.


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## Basil (Sep 24, 2021)

Another part finished. The Seal Major oil Trough. Unfortunately I was so involved with it I forgot to photo all the pieces. Too much solder but it will work fine.


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## kuhncw (Sep 24, 2021)

Very nice work on your oil tray.

Chuck


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## Basil (Sep 29, 2021)

Having never done seats this small before I thought I'd give this a try. I use this type of tool for final finishing and checking concentricity on larger engines and it works well.  
Taking one of the Dremel stones removed it from its shaft with a little heat and re-epoxied it to one I had machined to the guide. I have a collection of diamond dressers and found one suitable and machined the valve angle. I have ordered some 1000 grit compound for final finishing.  I've numbered the valves to keep them with seat when lapped. Hope this works!


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## Basil (Oct 14, 2021)

Done with the connecting rod pickups. I decided to thread them into the caps and locktite. Now on to the ignition which will be triggered with magnets on the backside of the flywheel. I have also installed a one way clutch and tooth belt drive pulley for the onboard starter. Getting close!


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## Weldsol (Oct 15, 2021)

Hi Basil your not far off from finishing, your definitely going to beat me to it.
Are you going to dry run it ? as in drive it from a motor or the lathe ? I know ETW recommended doing it for the sealion.
Like the idea of using a one way clutch for starting where did you get it from ?
Keep up the good work
Paul


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## Basil (Oct 15, 2021)

CSK17 17mm Sprag Clutch One Way Bearing Without Keyways 17x40x12mm Simply Bearings Ltd. This is the one way bearing. I am not sure if it will hold up to continuous overun at engine speeds but I must start somewhere. The pulley is 44 tooth 5mm pitch for a 10mm wide belt machined for a press on fit to the bearing. This evening I machined the mounts for the Hall sensors. Superglued to my rotary table. Machined from black Delrin and very happy with the results. I have spent some time making sure everything is clearance and free running. I'm a little concerned with the piston ring to bore seal and I think some break in will hopefully improve this. I am undecided on which oil to use on the initial start up. I run Joe Gibbs in all my race engines. BR20 is a mineral product that is recommended for break in rather than a full synthetic like XP10 or KRT, which I have been very impressed with. In these engines with aluminum to steel rotating assemblies (no shells) even the best mineral oils are not up to the job and I find a lot of scoring takes place.


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## Weldsol (Oct 16, 2021)

Hi Basil thanks for the info on the clutch.
Re initial lubrication I use Graphogen assembly lube, it's a colloidal graphite paste so it does not run off when applied but is dissolved by the engine oil  , I started using it in the past when rebuilding Caterpillar and International engines (quite a few years ago around 50yrs so it is not a new product) and it provides lubrication before  the oil has had a chance to circulate.

Paul


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## Basil (Oct 20, 2021)

Big smile! Very happy. I only had 2 stroke mix on hand. Will do some more setup with the correct fuel. Does anyone mix a little oil with the fuel?


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## gadabout (Oct 20, 2021)

I did when I first ran my little Seal, but quickly oiled the plugs up so went straight to plain petrol.
I also can’t play the movie, anyone else ? Is it because I’m on an iPad?
Mark


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## Weldsol (Oct 21, 2021)

Hi Basil told you would beat me, well done.
same problem as Mark with the vid it states codec missing cannot play format ??

Paul


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## exidy35 (Oct 21, 2021)

Hi All,
For what it's worth I can view this wonderful video with "VLC Media player"
Basil, you are to be congratulated on a beautifully built engine and thankyou for sharing your build notes with the community!!

Charles


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## Weldsol (Oct 21, 2021)

Hi Basil tried the vid again and it say's encoded not supported.
This is weird as I can view your other vids ??
Can I ask a favour could you send it to my email (if you still have it) please

Paul


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## Weldsol (Oct 21, 2021)

Weldsol said:


> Hi Basil tried the vid again and it say's encoded not supported.
> This is weird as I can view your other vids ??
> Can I ask a favour could you send it to my email (if you still have it) please
> 
> Paul


Hi Basil all sorted now love the vid it sounds brilliant
Paul


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## Basil (Oct 21, 2021)

Lets try this. I sealed the head studs with wellseal which was fine when the engine was cold but as the water temperature increased water started coming up the studs. I don't want to epoxy them in so I am trying high temp silicone and spaced the head up with wood shims and slightly preloaded the studs to take up any play. I also have a plan to join the 2 castings of the head with epoxy and make as one. 
Thank you for the kind words. It's been a fun project and I'm sure it wont be the last.


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## Basil (Oct 21, 2021)

gadabout said:


> I did when I first ran my little Seal, but quickly oiled the plugs up so went straight to plain petrol.
> I also can’t play the movie, anyone else ? Is it because I’m on an iPad?
> Mark


Yes Mark, I found the very same.


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## Weldsol (Oct 21, 2021)

Basil said:


> Lets try this. I sealed the head studs with wellseal which was fine when the engine was cold but as the water temperature increased water started coming up the studs. I don't want to epoxy them in so I am trying high temp silicone and spaced the head up with wood shims and slightly preloaded the studs to take up any play. I also have a plan to join the 2 castings of the head with epoxy and make as one.
> Thank you for the kind words. It's been a fun project and I'm sure it wont be the last.


Hi Basil these things re sent to try us, I may have the same issue with my engine but mine uses cap heads not studs so maybe not as easy to fix as yours.
Hope you get it fixed ok
Paul


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## JtH (Oct 22, 2021)

Basil, beautiful work.  I have a full set of castings, plans  and materials sitting ready to go in my Australian workshop, but am presently marooned in New Zealand ( not actually an bad place to be stuck)  Did you build the engine without reference to other resources or did you discover additional online resources - apart from this wonderful web site?  Once again warmest congratulations. You have set the bar high!


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## Basil (Oct 22, 2021)

Thank you, So very kind. This is my first model engine build, I took a lot of care with everything, learned a massive amount from this group. Wasn't sure how it would run though. I've wanted to build something like this for many many years. Today I discovered I'd made an error and got the twin coil firing order wrong. I'm used to 1-3-4-2 so I mistakenly placed the wasted spark on cylinder 3 instead of 4,  I was getting a number 1 fire but wasted on number 3 at bottom dead center. It runs better now! lol. You've always got to laugh at yourself.


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