Q? about re manufactured cylinder heads.

[er9]

Considering buying a re-manufactured cylinder head or possibly having mine rebuilt. questions is do the remanufactured heads normally come complete with new valves, guides, rockers arms etc...or do i have add those to the head afterwards?

[sailorchic34]

Generally a remanufacturered head is just the head, with new valve guides with valve seats and valves reground. cracked valves would be replaced but non cracked valves might be just reground. springs would be tested and if good reused. Head would be checked for flatness, etc.

Rockers, etc that are bolted on would not be included.

[a64pilot]

There are many different levels of overhauling, rebuilding and or remanufacturing. Best to ask cause it will differ from one shop to the other.
If done well, it’s as good as a new head.
If you have it done, then you can spec what you want, like bronze valve guides and Teflon or Viton seals etc.

[er9]

Great thanks...looks like it might be better to find someone local to re-build and be able to replace any/all parts as necessary then.

[a64pilot]

Originally Posted by er9

Great thanks...looks like it might be better to find someone local to re-build and be able to replace any/all parts as necessary then.

That is what I do, however a shop that does many and exchanges can often do very good work, and do it cheaper than one that does one offs, plus you get it a lot faster, so it’s a decision you have to make.
Me, I pay more I know but get to spec the components and tolerances.
There are usually two different limits for parts that have been in service, there is a serviceable limit, and new limits. I replace parts that don’t meet new specs, and you may be surprised at how many used parts meet new tolerances, but I feel better knowing my overhauled part meets new tolerances. Overhaul shops use serviceable limits, which they should, that is why those limits were established.

[Cheechako]

a remanufactured head from a reputable source will be complete, pressure tested and ready to install. Bolt on things like rocker arms will not be included.

[hellosailor]

What a64 said. ASK about options, and also ask about warranty. Many may only offer 90 days, ask if they'll go for a year.

Look at the shop, see if it looks reasonably neat and clean, or if it is a pigpen with screaming customers.

[er9]

Originally Posted by hellosailor

What a64 said. ASK about options, and also ask about warranty. Many may only offer 90 days, ask if they'll go for a year.

Look at the shop, see if it looks reasonably neat and clean, or if it is a pigpen with screaming customers.

thanks...I had a pretty reputable mechanic come and assess my engine. very nice guy, trustworthy. I think i'm going to give him a call and ask for a referall.

[a64pilot]

R&R of a cylinder head isn’t all that tough, and if your in a nice environment now, it would be a great learning experience. Expect of course to clean your heat exchanger, flush and fill with new antifreeze, and now is the time to have your injectors serviced.
Also expect to retorque your head although not all require that, and to readjust your valves pretty soon after they seat in.

[hellosailor]

"R&R of a cylinder head isn’t all that tough"
No, but if you really want to do it right, you'll have to walk him through CC'ing the cylinders, and porting and polishing the valve seats too.
All easy enough "while I've got it open" but so rarely done outside of gasoline racing circles.

[er9]

Originally Posted by a64pilot

R&R of a cylinder head isn’t all that tough, and if your in a nice environment now, it would be a great learning experience. Expect of course to clean your heat exchanger, flush and fill with new antifreeze, and now is the time to have your injectors serviced.
Also expect to retorque your head although not all require that, and to readjust your valves pretty soon after they seat in.

That was my original intent to do the rebuild myself but this dismantling is being done to try and solve a bigger problem. I decided against trying to do the head rebuild myself because if i screwed something up, even minor, i am worried it may continue to mask, or make worse the original problem i'm trying to solve.

Actually injector service/ rebuild is next on the list. If replacing/rebuilding the injectors solves my problem i may consider trying to do the head myself. i think i would enjoy the experience.

HA! heat exchanger/lack of raw water flow is what started this adventure. Heat exchanged is definately scheduled to come off, inspected, possibly boiled out and zinc replaced. I have a feeling its clogged but access is really tough. i need to cut an access panel through the wall in my quarter berth first. The access panel now only about 8" height and i can only get one arm behind the engine.

im assuming you mean check/re-adjust valves on rebuilt head after a period of time? if so how long? 25 or so hours in?

[a64pilot]

Originally Posted by er9

.



im assuming you mean check/re-adjust valves on rebuilt head after a period of time? if so how long? 25 or so hours in?

Yes, 25 is a good number in my opinion

[a64pilot]

Originally Posted by hellosailor

"R&R of a cylinder head isn’t all that tough"

No, but if you really want to do it right, you'll have to walk him through CC'ing the cylinders, and porting and polishing the valve seats too.

All easy enough "while I've got it open" but so rarely done outside of gasoline racing circles.

Three or more angle valve jobs, porting and polishing, matching ports, CCing heads are in my opinion of very little use for a little Diesel.
Doesn’t hurt, but I seriously doubt it would make much difference.
I have “blueprinted” race bike engines and not, and truthfully, even on a dyno I haven’t seen a difference, I think it’s more of a taking pride in your work and doing things “right” than it is a performance enhancer, like brightwork I guess

[Compass790]

Just a quick note to add my recent experience with refitting head. I found after 15 hrs intake v/v had virtually no clearance & exhaust v/v was way under spec so do retorque & check v/v lash. What bought it to my attention was engine losing power when hot. Had forgotten about the redo. Off today to retorque head as I forgot my torque wrench last time Too many Xmas spirits

[puffcard]

I was wondering is this gas or diesel engine. If diesel look at replacing the head bolts.