Resistance, intake valves

Seems like I need your help…
I put in a new head gasket and the head is back on. The timing scale points at 0 deg. and the damper has not delaminated (true TDC corresponds). The plugs are out.

The notch on the intake cam fits the tool perfectly. I’m turning the right way. The exhaust is a hair off, but that should be fine. All the lobes have been oiled. (It stood for a few weeks).
I have compression I can feel for and it doesn’t escape past the valves. Yet I have quite some resistance which caused me to look over everything again, and it is only when an intake valve opens. With some momentum it is easily overcome, which I now tried being relatively certain that things are in order. No funny noises, nothing.

The chain does tighten when I come to a resistance. I turn via the water pump pulley.

All suggestions are welcome; I hope this is normal but I won’t attempt to start it until I‘m absolutely certain. Any help is most welcome.


What are your valves clearances and do the valves open and close following the camshaft lobes? I am wondering if you might have a bent valve.



the valves open and close fully and follow the lobes perfectly.
Resistance is only there when the lobes start pushing onto the tappet. Almost as if the guide was fouling the cams. Valve clearances were undisturbed and as such the clearances themselves should be to spec.; also all would have had to change somewhat and I do have compression.
Thank you either way. I will recheck the clearances tomorrow. Especially now that the covers are off and I could re-shim.

As all inlet valves behave roughly the same way (#1 is the worst) I thought it might be one of the following:

  • gummed up oil in the valve stems, the exhaust valves have more clearance - I think it is easier to turn by now, would make sense.
  • the resistance is perfectly normal due to the above, nothing gummed up
  • I removed the rearmost bearing cap to see whether there could be friction as the valve spring pushes against the camshaft, possibility gone dry - but plenty of oil and nice bearing surfaces.
  • I ruled out any fouling between valves as the lobes don’t act simultaneously and the valve timing looks good. Same should apply for valve-piston contact. Also, no noises.

I think I was too cautious. It will probably be fine.

After I checked the clearances I will try and turn, later start it tomorrow. I expect a perfect idle with no hiccups. :slightly_smiling_face:
Thank you again.


Opening the valves against the springs does require some effort and this is certainly noticeable when turning the cams with the head off. For peace of mind I’d check the compression cold before you start the engine. You don’t care about the absolute numbers, just that they are all the same.If you have somehow bent a valve while the head was off it’s better to find it now as you can just take the head back off and fix it.

Also just check that you do have the upper timing gears bolted down properly to the cams. It is possible to get them slightly cocked sometimes when putting in the adjuster. Look at them as you rotate the engine and make sure they are parallel with each other and have no run-out.

Thank you, Andrew, I can do that.
Will report as soon as it will or won‘t run.


Best of British to you!

It helped. The engine got easier to turn by hand, then turned well on the starter. Compression felt good, but I‘ll do a leakdown and compression test after a few miles (which I’m sure it will do); I don’t know where that equipment is stowed just now.

Valve clearances are just in spec. and I‘ll leave well enough alone.
The new gasket fixed the issue and I got it to run very briefly, no causes for concern. The battery is charging now so it‘ll smoke up the garage tomorrow.

Thank you both for your help… I wouldn’t have been as confused if the exhaust tappets had had the same resistance.

Edit: it runs fine!