Best way to get the crank pulley bolt out

Any suggestions for undoing the crank pulley bolt Space is really limited, The best i can do is a 19mm off-set ring spanner due to the limited space, Not enough room to get a socket onto the bolt
One suggestion as been to use something to wedge the spanner and keep clicking away at the starter?
Will putting some heat on the bolt help?
Any suggestions appreciated before i push the T2 into the river at the back of the house

Just got the alternator off, what a t---, Intercooler out, passenger seat out-----------------

Try sliding another ring spanner on to the shank of the other and lock it off against it .Will give it more leverage .Can't see the starter shifting it Was this the same guy that sold you an alternator

Ill give all the options a go at the weekend, The guy that mentioned the starter idea is a 60+ year old mechanic, he reckons it will shift the bolt 90% of the time , Trouble with the T2 Lee is the space to work on it, so the starter idea will stay at the bottom of the list of options, Im sure my arms have got longer since i took the alternator off

starter option always works for me.

just make sure that the spanner will contact something solid and not damage it. make sure the spanner will travel at least 90 degrees before hitting the solid thing.

take the coil lead off so the engine will not start.

spin the starter over and duck!

bolt all be loose.

Pikey

Job done, Got myself bent double in the car and jumped on the ring spanner and it moved

had same problem with the race spider yesterday..... got the gas out and gave it a blast of heat..... problem solved!

I bought a Renault specific flywheel locking tool- basically a set of teeth for the flywheel and a flange with a bolt hole. Fits when you remove the flywheel cover plate- not easy in the car, but possible.
Not tried it on the 610, but worked a treat on our Honda for a cam belt change (even when it didn't fit quite correctly).
I bought it when I noticed the rear seal leaking. Changed the oil grade and it reduced to a weep, so I left it all alone. think it was 10-20 quid, cannot remember for sure.