Broken Valve Spring

[eschaider]

OP,

What you have here is commonly called a blown engine. By and large you do not want to replace just the broken parts with new good parts, that is a formula for follow on failure.

There is a good chance your engine will look similar to HTM101's when you finally get it taken down. If you have one dead piston when you replace just that one piston you could find it challenging to get it to the same weight as the other seven for balance purposes. The upshot is a new set of oversize pistons, pins and rings, boring the block, individually fitting each new piston to its new cylinder and or course rebalancing of the rotating assembly.

You can frequently that find shrapnel from the cylinder with the broken valve has found it's way to other good cylinders and done damage over there also. This would likely also require other pistons being replaced. Just buy a whole new set and do the job correctly.

When you finally get the head off, if the valve head has been pushed into the port throat damaging the valve seat, while repairable, the short way home could just be replace the old damaged casting with a new one. The exception to this would be a head casting that had significant additional work done on it for example like a nice porting job.

If you have a cracked or gouged cylinder you can certainly bore it and put a sleeve in it. For a high performance engine however, I might begin looking for a replacement block. For FE engines with all the availability issues they currently have, this will certainly become more challenging, especially in the current economic and supply chain impacted climate.

When a valve spring breaks there can be certainly two and sometimes three or more pieces. Your broken spring has many pieces. This could be an indicator that the engine was operated for some time after the initial break because the failure was not apparent to the driver. If that is the case then there is the possibility for broken spring pieces to have found their way into the oil system and done additional damage elsewhere in the engine.

Bottom line this is an R&R for the engine with a complete rebuild not just a cylinder head repair.


Ed