8-71N question

[Scarlett]

For. The engine experts how many hours would you expect it to take to replace a head gasket on a 8-71N and what should the parts cost? John

 

[dottieshusband]

There is no head gasket per se. There are individual cylinder sealing rings, oil seals, and coolant seals, and a big head perimeter seal. It is also necessary to replace the exhaust manifold gaskets, and usually a thermostat housing gasket as well. The head itself is fairly weighty. I'd set aside at least 8 hours to do it. Some would argue that the valves and injector timing would need to be reset, and some would remove the head with the thermostat housing and exhaust manifold still attached to the head, and injectors still in place. That is the quickest, down and dirty way, but it's a lot of weight. So, the quick way is to drain coolant, remove bypass tube, remove the valve cover, and governor cover. Disconnect the rack governor linkage and remove, Remove bolts from exhaust rriser, disconnect the hose from underneath the exhaust manifold. Remove head bolts, lift head with thermostat housing, water manifold, and exhaust manifold attached, replace sealing rings, and oil and coolant seals.... 2 to 3 hours that way...BUT, it's rarely just a sealing ring, and unless you can rig the head to support the weight, you're are asking for trouble. I installed a jib crane in my ER to facilitate lifting and supporting heavy weight.... batteries, head, manifolds, blowers, etc. Parts would be less than $80 bucks.

 

[Glory]

A blown/failed head gasket on an 8-71 is very uncommon.

 

[jim rosenthal]

Just curious- what the the issue which suggests the head needs to be changed or removed?

 

[Scarlett]

Based on comments by an engine surveyor and running at WOT with a bit more smoke than it should. Smoke was not overly excessive, but more than normal.

 

[dottieshusband]

Based on comments by an engine surveyor and running at WOT with a bit more smoke than it should. Smoke was not overly excessive, but more than normal.

Yeh, no... I would not suspect a head sealing ring from that description. Compression testing is easy and quick and would point to or away from a sealing ring. Smoke at WOT is really not that unusual, although mine does not. But it's unburned fuel, or burning oil. Injector or possibly a valve or ring issue most likely. Even possibly a fuel contamination or quality issue. But I wouldn't suspect a head sealing ring.

 

[spartonboat1]

This post is not overly old. What was the finding, re: possible head gasket/sealing ring(s) and what was the resolution, if known?