Geoff NZ Posted February 12 Report Share Posted February 12 I have a problem with my 1970 CP crankshaft. Long story short, I refurbished various aspects of the car from the dashboard forward during 2023. Most of the engine work was completed in June/July then all work on the car stopped in August due to spinal surgery. I got stuck in to it again early this year to finish it off for a major club road trip later this month. Engine work involved re-worked head with new valves, springs etc., new cam lifters, new rocker shaft assembly, ARP head studs and a lot of peripheral work to manifolds, sump, hi-torque starter motor and much more. The block was flushed out but no work was done inside the block other than cleaning the oil pump gauze while the sump was off. Cam lifters and cylinder walls were lubricated prior to cylinder head fitting. The re-worked rocker shaft was bolted down, tappets adjusted and at that point the crankshaft was relatively easy to move using a spanner on the crankshaft pulley (no fan blade). Engine oil was added but the oil pump wasn't primed at that stage. The car has been sitting in the garage for 6 or so months. Having just removed the distributor pedestal and drive gear to prime the oil pump, I thought I'd bring it up to TDC to reset the timing from scratch (should have done it prior to removal but the result would have been the same). Low and behold, the crankshaft won't budge - no movement at all. Obvious thought was it was still in gear (been caught by that one before) but it's definitely in neutral and I can push the car back and forth. Don't want to put too much torque on the crankshaft pulley. I've removed the rocker shaft and loosened the fan belt to relieve any possible pressure and still no movement. I didn't expect this and I'm at a loss to know what's causing it and how to rectify it without major surgery thus undoing a lot of the good work I've already completed, so any pearls of wisdom would be gratefully received. Thanks in advance. Quote Link to post Share on other sites
JohnC Posted February 12 Report Share Posted February 12 FIrst, don't assume the worst (whatever that is). In your place I would remove all the spark plugs, put the engine in gear, and see if a bit of rocking by rolling the wheels back & forth shifts things. BTW removing the rocker shaft may have made things more difficult. All your valves are held shut by their springs, so harder to turn the engine. hope this helps, JC Quote Link to post Share on other sites
Nigel Triumph Posted February 12 Report Share Posted February 12 (edited) Despite oiling the cylinders when refitting the head, is it possible the piston rings have stuck to the bores while static for 6 months? I would try pouring diesel in through the plug holes and leave 24 hours to free off any sticking rings. Then try turning by hand with the plugs out From memory the crank pulley bolt is torqued to 80-100 ft lbs, so don't be afraid to lean on it hard to turn the engine! Nigel Edited February 12 by Nigel Triumph Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 12 Report Share Posted February 12 Have you taken all the spark plugs out and tried to rotate the crank? Quote Link to post Share on other sites
Mike C Posted February 12 Report Share Posted February 12 1 hour ago, BlueTR3A-5EKT said: Have you taken all the spark plugs out and tried to rotate the crank? +1. If you've filled the radiator with coolant you might a piston locking up due to a leaking head gasket. Quote Link to post Share on other sites
Andy Moltu Posted February 12 Report Share Posted February 12 Take the plugs out to check there's not a hydraulic lock. Try and turn it with a socket and and see whether water comes out. It should if it turns it should take less than 20ftlbs of torque. Quote Link to post Share on other sites
Geoff NZ Posted February 12 Author Report Share Posted February 12 Thank you all for your replies. Plugs were not installed and cooling system is empty. My first thought (other than gear engagement) was sticking rings although it has never happened before after periods of lay-up. I also tried very gentle rocking in 4th gear but didn't overdo it for fear of breaking or bending something. Quote Link to post Share on other sites
PodOne Posted February 12 Report Share Posted February 12 Just a thought but before you apply some pressure I'd just check that nothing has entered through the plug holes or fallen down the push rod holes that could lock the engine up like a stray nut/bolt. Failing that some WD40 or diesel down the bores left to soak overnight might help. Andy Quote Link to post Share on other sites
Mike C Posted February 12 Report Share Posted February 12 Was the new starter installed when the engine turned freely? Quote Link to post Share on other sites
Geoff NZ Posted February 12 Author Report Share Posted February 12 Pretty sure nothing unwanted would have dropped in - rocker cover was in place so only plug holes exposed. Starter motor was in place when tappets were adjusted so no problem there - I calculated 3mm clearance between bendix and flywheel. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 12 Report Share Posted February 12 4 hours ago, Geoff NZ said: Thank you all for your replies. Plugs were not installed and cooling system is empty. My first thought (other than gear engagement) was sticking rings although it has never happened before after periods of lay-up. I also tried very gentle rocking in 4th gear but didn't overdo it for fear of breaking or bending something. Nesting Kiwis? Quote Link to post Share on other sites
Geoff NZ Posted February 13 Author Report Share Posted February 13 No brown Kiwis Peter but a brown invasion of another kind - camera inspection shows rust smears on some of the cylinder walls so my suspicion (and Nigel's) of stuck rings sounds about right - even though the bores were oiled, a 6 month idle period was obviously a bridge too far. Off with its head and I'll clean it all up - again - oh joy. Only consolation is that everything will dismantle a hell of a lot easier this time. Thank you all for your suggestions - much appreciated. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 13 Report Share Posted February 13 2 hours ago, Geoff NZ said: No brown Kiwis Peter but a brown invasion of another kind - camera inspection shows rust smears on some of the cylinder walls so my suspicion (and Nigel's) of stuck rings sounds about right - even though the bores were oiled, a 6 month idle period was obviously a bridge too far. Off with its head and I'll clean it all up - again - oh joy. Only consolation is that everything will dismantle a hell of a lot easier this time. Thank you all for your suggestions - much appreciated. Check which cylinder head gasket was fitted. There are two types which are not interchangeable. The difference is based on if the top of the block is smooth or has a recess cut around each cylinder bore. Quote Link to post Share on other sites
Geoff NZ Posted February 13 Author Report Share Posted February 13 Thanks Peter - smooth block and correct head gasket - all sorted first time around. Quote Link to post Share on other sites
Casar66 Posted February 16 Report Share Posted February 16 (edited) On 2/13/2024 at 10:13 PM, Geoff NZ said: ...even though the bores were oiled, a 6 month idle period was obviously a bridge too far... I do not think that just time is the reason for the rust. I am living in one of the humids area here in Germany and never had rust in whatever engine whilst not using it for a while even longer than 6 months. I guess there must be another reason Edited February 16 by Casar66 Quote Link to post Share on other sites
FatJon Posted February 16 Report Share Posted February 16 I have left closed engines in pretty damp places for years without rusted bores. Just rebuilt an mx5 engine which has been on a damp barn floor for 10+ years. Externally it was a rusty mess but internally shiny metal. It was drained of coolant but had oil in it. Quote Link to post Share on other sites
Mike C Posted February 16 Report Share Posted February 16 It's pretty common to leave boat, farm machinery and irrigation pump engines for 6+months between starts. I've never have had such an engine fail to crank over on restart. Quote Link to post Share on other sites
Andy Moltu Posted February 17 Report Share Posted February 17 Have you put a torque wrench on it? Set it at 20 ft lbs which may seem quite a lot but isn’t unusual for a newly built engine that hasn’t run. Quote Link to post Share on other sites
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