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As far as I’m aware, Ther are no guides in the 8.1 stock heads. It’s just the reamed out steel and valve. No guides. Not that the manifolds will be switch to also be FWC withe the new set, it should be ok, but would like the extra protection of added corrosion resistant guides.
I’m in no rush. I’ll search online for new GM and then used. What is a fair price for a used set? Car-parts has plenty for about $200 a side. I would send it to the machine shop to be refreshed of coarse. |
Originally Posted by lmannyr
(Post 4927311)
As far as I’m aware, There are no guides in the 8.1 stock heads. It’s just the reamed out steel and valve. .
If you think about it paying $200 for a used head makes no sense if you can get a new one for $350 Its probably going to cost you at least $600 plus parts to refresh a set of used heads. If you buy new all they will have to do is clean and reface your valves if they are ok and check everything else on the new heads and put them together. Depending on how many hours yours have it would probably be a good idea to put new springs on them. It seems like every single time one of my customers buys a used head or other engine parts they regret it in the end. Usually costs as much to fix the old junk than to buy new. |
Originally Posted by BillK
(Post 4927313)
That is how every cast iron GM head in the world is :) They work just fine. How long have yours lasted ? I did a Mercruiser 8.1 about a year ago that had almost 1300 hours on it !!!! Had never been touched and the guides were still fine. Depending on the application a lot of times the factory setup is a lot better than people think. No need to rethink it.
If you think about it paying $200 for a used head makes no sense if you can get a new one for $350 Its probably going to cost you at least $600 plus parts to refresh a set of used heads. If you buy new all they will have to do is clean and reface your valves if they are ok and check everything else on the new heads and put them together. Depending on how many hours yours have it would probably be a good idea to put new springs on them. It seems like every single time one of my customers buys a used head or other engine parts they regret it in the end. Usually costs as much to fix the old junk than to buy new. $350 for new? Where? Have a link? At that price, I would prefer to get new. Is this bare or all the valves, springs etc..? 1300 marine hours on a no guide head? Nice! Thats great. Doesn't sound like a really need the guides then....especially with FULL FWC system. |
Head Casting is the same on both sides? 12558162 One head has F202 the other has F282. Would think the longer number would be different for left and right.
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New Bare GM heads on order. Ordered no valve stem seals, valve cover bolt grommets (many were ripped), Head bolts, head gasket, intake gasket.
Currently stripping the valve cover, and cross over pipe for prime and repainting. Cleaning up the engine bay as much as possible with only the block in the way now. Injector baskets on order, cleaning fuel rail. New "Paintless" fuel cell on order. I plan to reuse the same valves, springs, retainers, keepers and move over to the new head myself. Anything I should be careful about this process? I'm more concerned with proper seal of the valves. I'll clean up the valves with a scotch brite and carb cleaner. |
Originally Posted by lmannyr
(Post 4927444)
I plan to reuse the same valves, springs, retainers, keepers and move over to the new head myself. Anything I should be careful about this process? I'm more concerned with proper seal of the valves. I'll clean up the valves with a scotch brite and carb cleaner. |
Maybe 500 hours on engine.
Whats the best way to clean the intake manifold and the the block gasket surfaces? Will take the heads to the shop and have them reface/replace valves and springs as necessary. I’ll have them replace the keepers as well. I appreciate the help. Should I remove the old valves and take them in or have them do it. I like doing as much as I can my self. I enjoy tinkering and working with my hands. I don’t mind saving a few bucks while doing some work myself. |
8.1L Marine application.
After soaking in diesel, chucking in a drilling wiping with a Terry cloth. Thoughts on these valves? Whats the cause of the pitting? The back sides are all nice and smooth on both intake and exhaust valves. The pitting is only on some the intake valves. One in particular has some chips on the edge. I'm assuming the pitted valves need replacement. Since its at least 4 of 8 intake valves, the plan would be to replace all the intake valves. Thoughts? https://cimg9.ibsrv.net/gimg/www.off...3f7538aae.jpeg https://cimg1.ibsrv.net/gimg/www.off...eff905eaf.jpeg https://cimg2.ibsrv.net/gimg/www.off...e49e3fe99.jpeg https://cimg3.ibsrv.net/gimg/www.off...8b2e99412.jpeg https://cimg4.ibsrv.net/gimg/www.off...bb527c2e8.jpeg https://cimg5.ibsrv.net/gimg/www.off...f94d847d0.jpeg https://cimg6.ibsrv.net/gimg/www.off...777dd32bb.jpeg https://cimg8.ibsrv.net/gimg/www.off...337d55f96.jpeg https://cimg9.ibsrv.net/gimg/www.off...69d91d92d.jpeg https://cimg0.ibsrv.net/gimg/www.off...c8fac0fe5.jpeg https://cimg1.ibsrv.net/gimg/www.off...bdc98b093.jpeg |
Holy cow, that's a lot of pitting... I also noticed in the pictures of the block, there is quite a lot of pitting on the deck surface... you might want to remove the head gaskets and see if that pitting is under that surface as well.. If it is, you might have to pull the block and get it decked... This almost looks like it sat full of water for a long time...
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