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DIY Head Resurfacing... or "Post-apocalyptic machine shop techniques!"


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GD - can i use this method to also resurface a flywheel?

 

if it's good enough for a head, seems good enough for a Ford F150 flywheel to me?

 

A granite slab would work the same, and might be easier to find for the price. Look for a cut-out from a sink for a countertop. Sometimes you can get a fairly sized slab that is just shaped wrong to use for anything, but big enough for the job.
i ended up getting a huge piece of granite for free from a friend...but after looking into it not all granite is necessarily flat. there are common practices that give that kind of finish but there's no guarantee that a particular piece has that finish.
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One thing I'll add..... To my knowledge I have never had an engine blow a head gasket after I've replaced it. I've been doing this Subaru thing for a few years now and I have done a ton of engines both ways - machine shop and home resurfacing. Neither has failed me yet. Part of this I attribute to attention to detail and cleanliness.

 

If a job is worth doing - it's worth doing right and to the best of my ability.... something my grandfather passed on to me and it is THE most important concept that permeates my shop. Anyone that has worked in the shop with me knows that I will hold them to it as well while they work under my supervision. No half-assery on my watch!

 

GD

 

if only more people felt this way GEEZ! good looking out general your an upstanding guy!

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  • 10 months later...

GD,  An excellent thread and I'd like to thoroughly endorse the method; one I've used myself on and off since the 1960s. The only difference being that we used to use grinding paste spread directly onto the glass because sheets of wet and dry were often a bit lumpy in those days and hard to find as our local supplier sold it in narrow rolls. Also the contact adhesive required the glass to be ground if it was to stick well.  A great thread.   

 

Oh, I nearly forgot: on small motorcycle and lawn mower engines we'd do the same to the top of the barrel and run them without head gaskets to get the extra compression! We thought if it's OK for Bugatti it's OK for us :-)

Edited by NickNakorn
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  • 2 weeks later...

for the right price i'd be interested.

 

shipping to 24014.

 

thanks,

john

Fed ex shows 24.30 shipping to you.

Price on Glass would be $15.

So total is around $40

 

Can take one or more to Boise with me on Monday and ship if you want.

P.M. with address.

 

Hush

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While it generally works OK on single cylinder motorcycles and effectively twins also like Subaru's one must always be carefull with higher compression engines or Turbocharged ones to make sure the Chamber volume is at least consistent between cylinders or it will ping/detonate on one cylindser under the right circumstances.

 

Even some machine shops get that wrong so it pays to measure the actual head thickness at each end on a Subaru ie measure from head gasket surface to rocker cover gasket surface.

With the example shown while warpage is obvious it is centralised as normal with Subaru heads so the chamber volume while smaller will likely be even between cylinders,However if the same occurs with a set of V8 heads or an inline 4 then the outer cylinder can end up with a noticeably higher static compression ratio than the inner cylinders,With a high performance hi comp or turbo motor that can lead to detonation issues.

 

I have also seen heads from a datsun B110 (1200) that were dcifferent to the tune of 60 thou less material at one end done by some machine shop so when I measured the chamber volumes there was a range of 11cc difference between one end and the other,Just a warning of another thing to look for when doing this method or for that matter after the shop machines something for you.

 

A cheap method of cc heads is to use a bit of perspex and go to the local Vet and buy a graduated syringe a big one to fill with kero to actually do the measurement,Seal the perspex with grease and it needs two holes in it,One to fill through and one to bleed the air.I am lucky enough to have a proper burette setup but the above method works OK done with care.

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Fed ex shows 24.30 shipping to you.


Price on Glass would be $15.


So total is around $40

Can take one or more to Boise with me on Monday and ship if you want.

P.M. with address.

Hush

thanks, but  i think i'll have to wait a bit. lots of other stuff coming up in may.

hopefully i can find something local.

 

but thanks for getting back to me.

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Resurfacing flywheels is another thing altogether the equipment is very expensive but I know someone who made their own flywheel grinding machine and it cost about a thousand dollars all up.

This may interest you Shawn as it is doable and saves waiting for the machine shop when you do not have a flywheel grinder and works a treat.

 

Stan started with a round table drill press made in Taiwan and converted the table to run on tapered wheel bearings,He them made up an adaptor to take a cup style grinding wheel and ran the press at the lowest speed possible,then by giving the now free spinning table a spin and lowering the cup type grinding wheel to the table he dressed the table to be perfectly square to the grinding wheel.

 

When clamping a flywheel to the table one simply offsets the  table to the centreline of the grinding wheel slightly and gives it a spin and the grinding wheel offset keps it turning nicely when the cup type grinding wheel is lowered down to reface the flywheel.

 

The result is a perefect finish that cannot be distinguished from the work being done on a machine worth ten to twenty thousand dollars but it cost less than a thousand and a day to make.

Edited by coxy
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Fed ex shows 24.30 shipping to you.

Price on Glass would be $15.

So total is around $40

 

Can take one or more to Boise with me on Monday and ship if you want.

P.M. with address.

 

Hush

 

 

I don't want to take away from John's offer but I'll take one of those pieces of glass if it's still available.  That's awesome..if you think it'll ship okay?

I'm currently using something like half that thick.  Can paypal or whatever immediately.  Heck I might take two, combine shipping, and just get one to John somehow, I'm driving through VA this summer....

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  • 4 months later...
  • 1 month later...

I should make something like this because the local machine shop treats subaru heads as "V6" heads so they want 45 a head or 75 if both are done.There used to a cheap machine shop in town but napa auto parts bought them out so now there is only one shop in town so they can charge bank for any and all engine machine work.

Edited by Uberoo
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  • 3 weeks later...

Did my 2001 2.5 SOHC heads today.  I used some Corian Counter top I'd cut for cutting boards, flat as glass I believe and spray adhesive.  

 

The Loctite General Purpose spray adhesive worked great.  I started with 180 grit until I had all the marks gone and then finished with 400.  That's what I had on hand.

 

If anyone wants some 8.5 x 12 Corian I have plenty.  $5 each + shipping.  Buy two one for course grit and one for fine.  Better get a couple for the kitchen also.

 

Larry

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Sounds like I should be doing the valves on my EA82 heads when I do the gaskets. I'm no up to doing the valves (to much I screw up there) I'm fairly certain I can do the resurfacing once I get the material, that being said I'm just wondering if it will be worth my time and ect to do that if I'm going to take them to the shop anyway for the valves??

 

Thoughts anyone??

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  • 6 months later...

Hey there thanks for an awesome post. I am doing my headgaskets for the first time on my ea82 and used this approach.

 

Here is my set up. I used a spray on cement to help keep the adhesive evenly distributed.

post-49592-0-23012400-1401805706_thumb.jpg

 

This is where I started

post-49592-0-81462000-1401805805_thumb.jpg

 

Somewhere in the middle

post-49592-0-05332100-1401805825_thumb.jpg

 

FInal product after swapping to 320 finish

post-49592-0-91422500-1401805839_thumb.jpg

 

I measured it with feeler gauges and it is now within spec.

 

Any tips how to deal with the block or should it be left alone after removing gasket material? Some of that material is on there pretty good...

 

 

 

 

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Have done over 150 heads on my van Norman 570 since I got it 2 years ago. The heads that give me the most grief are the twin cam 2.5 heads. Or any overheated badly heads. Taking very small amount off at a time helps I also put the heads in the freezer 1rst to get the aluminum to tighten up. They surface better cold

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  • 2 weeks later...

OK, took some thought where to best affordably source a pane of glass (long a sound , like glarce) and went to the dump shop, left a poor condition cane coffee table settee sans glass top :) and paid $4 for 6mm thick 2.5' x 1.5' ready for some backing form ply. Expensive bit was $15 for contact spray adhesive, and 1.98 for 220 grade sheet of paper wet n dry

 

Alternative cost was quoted A$80 each head just for surface grind, not even a compression hike shave !!

 

next sheet needed, found i was paying for convenience or quality at first place for sheet wet n dry.

 

Picked up some flexovit metal grade 240 think it may be more robust or do faster job ? Or faster to muck up !

 

the first head is as true as both sides of the straight edge

Edited by jono
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  • 2 months later...

I wonder if it would be possible to continue on to 600/800/1000 grit and get the RA down between 20-50.

Or what about this same method for the block side?

 

 

 

 

 


Edit: Actually, my estimate of the necessary grit to RA was grossly inflated. It seems that 320 grit would already be in the ballpark of 20-50 RA.

http://www.sunnen.com/graphics/assets/documents/e2e25e493b00.pdf

Edited by Ibreakstuff
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  • 4 months later...

Why is this EZ30 head taking forever and many sheet changes?

 

I've done a few heads - takes 20 minutes and a few sheet changes.  This EZ30 i've changed the sheets 4 or 5 times and still has light markings around center cylinder.

 

Can I speed things up with 100 grit first?  If it's taking this long it hardly seems like it would matter?

 

This head was just that far off?

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