sj413 engine

[jim tylee]

Just been reminded of a episode with friends Suzuki 413....he loves Redex in his vehicles.....so he thought he would put a squirt into each cylinder while plugs were out.....on startup lots of blue smoke as one can expect ..it turned over quite slow before starting i noticed.....off he went but only for a short time on arriving back to my garage he said something is wrong...i drove around the block and it was certainly not right no power......compression test no3 cylinder very low .....head off and guess what head gasket had blown in a big way by no3 ........i think that the Redex in the cylinder had made the psi so high the gasket gave way, anyway new gasket and no more Redex for this Suzuki anus
Jim

[twiss]

Redex in the cylinders? Never heard of that one before lol

[jim tylee]

He had read that it frees gummed up piston rings
Jim

[twiss]

Hmm personally for that I would have poured a little bit of oil in each cylinder, leave it overnight, then take the spark plugs out and turn the engine round with a socket wrench on the crank pulley nut

[Ladaman]

I think it frees up rings if left to soak. It will also seep through and past the rings and harmlessly mix with the oil.

If you put too much in re fit the plugs and the crank it over, on the compression stoke it will have no where to go and BOOM gasket will go.

Lesson to be learned there?

[RickUK]

Redex as a general rule was always added to the fuel by a set amount to a full tank of fuel,this over time did work by reducing the amount of carbon on the valves and valve seats,but it was mainly aimed at older cars.

Gut feeling tells me that a fair amount was added into the bores via the plug holes and after starting it could well have caused a hydraulic lock effect and this then took out the head gasket which was the weakest link.

Of course i could be wrong but modern cars dont tend too coke up as much as they did decades ago,a very small shot of oil or any lubricant down the bores in theory wont do any harm,its best to turn the ngine over without the plugs in afterwards to get rid of most of the excess oil so that hydraulic locks wont happen.

At least its working again.