Major Seal 30cc Build

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Weldsol

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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
 

Basil

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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
 

gadabout

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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
 

Charles Lamont

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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

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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

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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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Basil

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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

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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

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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
 

Basil

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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

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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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