Hitchcocks Forum

Hi All


In an effort to get the oil to stay inside the engine of my Silver Bullet project (09 Electra EFI) I've been replacing gaskets on the head etc and assembling with a small amount of silicone sealant. During this process I replaced the standard (0.9 mm ish) base gasket on the barrel with one of the thin ones from our Hosts (0.4 mm ish) and re-used (after re-annealing) the 0.3 mm copper head gasket. The problem is that during re-assembly I found the valves were being pushed open despite the engine being set to TDC with both valves "closed".


This particular engine has the Hitchcock's cams fitted along with the longer pushrods and high performance valves. In order to cure the no compression problem I've now fitted the standard pushrods and the engine starts and runs - although I've not taken it out for a ride yet.


Does anyone know what the maximum "adjustment" (I know, they adjust themselves) that can be achieved by the hydraulic tappets? Have I done the right thing putting the shorter pushrods back in or is there a way of collapsing the hyd tappets that I should have done whilst re-assembling the engine? Any advice please?

So, to answer my own question, I reckon the maximum adjustment you can get out of the hydraulic tappets is about 4 mm. I've just measured it having had to dismantle the exhaust tappet in order to get it to compress.

Did you follow the instruction sheet that H supply with the cams?


It can take 10-15 minutes for the Hyd lifters to Bleed-Down before you can turn the motor over...

I have yet to attack one of these engines with the spanners, but would it be possible to convert to the 'Classic' type pushrods, with manual adjusters on their ends and do away with the hydraulic adjusters? Regards, Paul.

Tim



The tappets had about 3 weeks to Bleed Down! When I stripped it there was evidence of running in type swarf in there, so, washed out with petrol and reassembled with some clean oil. A bit of playing around with it revealed that a few compressions of the tappet makes it go firm, and comparing measurements between fully compressed and fully extended (the spring loaded position) is about 4mm.



Paul



Hi, we spoke the other day. I think it'd be possible to replace the hydraulic tappets with solid ones, but there's not as much access to the bottom end of the pushrods as there is on the older engines (I'll e-mail you some photos). Getting the tappet retaining pins out was an absolute swine of a job without splitting the engine. The suction on the pin was such that simply pulling it out with pliers was impossible so I made a very simple special tool to do the job. It was a bit rough but it worked. Regards, Andy.

The EFI unit construction has been around for nearly ten years and still nothing has been added to the tech notes..

Tim says theres an instruction sheet with the cams, couldn't this be published so we all get a look at things Enfield?

How to access the gear clusters or indeed replacing push rods.

Seems to me Conti 250 is catered for, along with 4 speed boxes and carbs but nothing about B5, C5, G5 etc fork differences, EFI to carb conversions..

Just a few words and photos to expand the tech notes to the modern day would be nice Mr H..

“…it is important with the pushrod positioned on top of the lifter with no cam lift, the rocker and rocker housings are then placed on the head with the fixing screws loosely attached with NO PRESSSURE. at this stage it would be expected for there to be between 1mm and 2.5mm gap between the base of the rocker housing and the cylinder head (if the valves are being held open beyond this, there is too much preload which can be solved with a slightly shorter pushrod). When you then tighten the 4 fixings this gap will close up. Due to oil in the lifter, it is very likely that when tightening the rocker housing the valve will open. You must allow 10 – 15 minutes for the lifter to ‘bleed’ before turning over the engine. This should allow the valves to close.”


The H cams have a different base circle dia, thus replacement pushrods ARE required to be fitted, and the cams do not have the auto decompressor provision...