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-   Engine Performance (https://www.miataturbo.net/engine-performance-56/)
-   -   One reason I doubt alot of machine shops. (https://www.miataturbo.net/engine-performance-56/one-reason-i-doubt-alot-machine-shops-66195/)

m2cupcar Jun 4, 2012 09:00 AM

All main caps were in the OE locations. But I too have been in the "it's a race engine rough luck" club.

Braineack Jun 4, 2012 09:20 AM


Originally Posted by Braineack (Post 883928)
What was all the sand from?


yeah really, I'd like to know too.

TurboTim Jun 4, 2012 12:07 PM

Stuff like this makes me very scared. It's why I bought a welder and a laptop for tuning. now I need a sunnen or whatever?!!? Or sell it all and buy a minivan.

BogusSVO Jun 4, 2012 12:49 PM

The sand is from cleaning the casting, But first thing is the casting has to be totaly dissassembled, (oil galley plugs removed). The casting MUST be fully dry.

Shops that glass bead, or shot blast on the norm will thermal clean a casting first.

To me sand is too abrasive, so I use a fine glass bead media.

The shop that did this head first runs the head thu a spray cabinet, then sand blasts... Thats a big NO-NO in my book for several reasons.


M2CupCar.... Have the crank checked for straight, I would bet it is bent about .010 or more from the wear patterns I see of the bearings. #3/center looks good in both the upper and lower halves.

If he had got the alogn hone tight, I would expect the wear pattern to be the same all the way thu, and show copper on both the upper and lowers.

leatherface24 Jun 4, 2012 01:09 PM

I cant laugh at this. I had a horrid experience once...picture the moron that sent this back to you in that condition only to blame that damage and rebuild on UPS..

BogusSVO Jun 4, 2012 01:16 PM

leatherface.... he did not blame anything on UPS, well the broken cam gear, to me, that is part His and part UPS.

The first shop that did the build, is at fault, no doubt at all about that aspect, the sand, the cam caps in the wrong spots/backwards, the valves swapped...

BogusSVO Jun 4, 2012 01:31 PM

BTW... this "sandy" head left my shop like this...

This is the "before" I worked it over..

This is the "After"..

https://www.miataturbo.net/engine-performance-56/head-build-modified-66086/

He is all sorts of happy with it now, still sorting a few issues out in the driveline, but he has fired the engine off.

samwu8k Jun 6, 2012 02:04 AM

i dont have much machine shop experience only had a head resurfaced 1 time. i was under the impression i had a perfectly good head because i took it off my personal car that had like 65k on it. very well taken care of never overheated and i loosened it slowly and evenly to avoid ------- it up and when i went to pick it up the guy starts telling me a story about how it was really warped and he had to take ALOT of metal off to get it straight. i found it sitting on the freshly machined surface on their dirty ass steel table, and it had metal powder on it. i honestly thought if they resurface a head they wash it afterwards but idk maybe thats just this machine shop.

Braineack Jun 6, 2012 08:19 AM


Originally Posted by leatherface24 (Post 885180)
I cant laugh at this. I had a horrid experience once...picture the moron that sent this back to you in that condition only to blame that damage and rebuild on UPS..


:(

miatauser884 Jun 6, 2012 08:42 AM


Originally Posted by soviet (Post 883099)
what.
are.
your.
rates?

This is what I was about to ask. I think you will get a lot of business from members on here. I would send my stuff to you just to have the peace of mind that everything was done right.

m2cupcar Jun 6, 2012 08:53 AM

Bogus- the builder was contract for the entire bottom end machine/build/assembly. My guess is he didn't check the crank.

Full_Tilt_Boogie Jun 6, 2012 11:43 AM

Ive got a good one.
Buddy of mine takes his block to a local machine shop to have it bored 0.5 mm over. It takes them forever, and finally when they finish it, they inform him that they made a mistake on one of the cylinders and had to sleeve that one cylinder.
Then, first day of running, engine is broken in, oil changed, and we are just driving it, tuning for driveabilty, when the camshaft locks up in the head. We get it home, take the head off and find the valves hit the pistons and hat the cam is locked up, then when he goes to turn the engine over by hand the ------- sleeve comes out of the block with the friction of the piston!

Turns out after having the block such a long time and then making some mistake boring it, they did a quickie job throwing that sleeve in there. So were driving down the road and that sleeve is just banging up and down and spinning around inside the liner, filling the oil with shavings. The shavings then cause the cam to seize up.

That shops shitty work cost him a turbo, a 59300 cam, skunk2 valves, low compression pistons and his previously good condition block and head.
Of course, they claim it was his fault.

RyanLewo Jun 6, 2012 12:27 PM

Oh man... This thread is freaking me out! lol.

My engine is currently at a shop as we speak for a build which included polishing the crank, installing new ACL Race main and rod bearings, surfacing the head, cleaning, installing new valve seals, installing H-Beam rods to stock pistons with new rings, and mating the head.

I am really hoping they don't ---- something up... Ugh.

-Ryan

Edit: If they do I'm calling BogusSVO for help! lol.

BogusSVO Jun 6, 2012 12:44 PM

M2... I agree, prob a quick polish and set it in the block, "It ran before, It will run again" mentailaty.

Full Tilt Boogie... sounds like they got the sleeve press fit wrong, it should be about .005-.007 ( some shops go as little as a .002 press fit. Also if it had that much movement they did not "Lip the cylinder" That is where when installing a dry sleeve, you leave a lip appox .250 or so (Eyeball measurement) in the bottom of the block so the sleeve sets against it, then cut the sleeve down at the block deck then surface it.

This way the sleeve is locked in place and can not move.

Some green sleeve retaining lock-tite is added insurance.

I was just over towards Jax this past weekend (Middleburg) I would have poped over and looked at it had I known and it was still around.

Rayan.. he is building the long block then.
How is he milling the block and head? what equipment?
What Head Gasket are you going to use?

How to mill an alum head
https://www.miataturbo.net/showthrea...818#post863818

How to deck a block
https://www.miataturbo.net/engine-performance-56/how-deck-4-cylinder-engine-block-64577/

Why Not to have your head belt surfaced
https://www.miataturbo.net/engine-performance-56/why-not-let-your-head-belt-surfaced-64394/


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