Best source for a bare short block
 

So I found a bare short block locally here in AZ that had some slight damage to cyl #2 due to a melted piston. Well the machine shop bored the damaged cylinder out .020 and that did not fix the problem. There is still a little bit of scoring left in the cylinder after the bore. He said going .040 over should take care of it but would require me to run a 90mm piston which I dont really want to do. So now i'm in the search for a new or used bare short block. Where is the best source to get a new or used bare short block so I can continue my build?

Kind of sucks I paid $500 for this block with a crank and i'm to nervous to bore it out any further to fix it. I guess I can look at it on the bright side, the crankshaft that it came with is in perfect condition because i'm sure my crankshaft is damaged or bent after how bad my ZZB was.

Thanks for the referral!

Eric

Look into sleeving that block? It might be cheaper then buying another block.

Also have you tried junkyard searching?

Car-Part.com--Used Auto Parts Market

Hey Big PAPA! Yes I was looking into sleeving but the shop that has the block was hesitant to do it. They said since it's an aluminum block they would really have to take a lot out to resleave it back to stock or 88mm size. They said they would have to cut into the aluminum and felt this might compromise the block by doing so.

They said that going .040 would probably fix the rest of the scoring in the cylinder which would put me at a 90mm piston. Are there any people here running 90mm pistons with a CR of 10:5:1? I know CP-E has pistons that big but i'm not sure what kind of issues i would run into with compression that high and pistons that big and what the driveability would be like once its up and running.

Has anyone resleaved one of these blocks before and not had problems afterwards?

I have done a lot of work with our engines ford cousin the duratec. Sleeves are expensive and should not be done on just one cylinder. It is best to do all 4.

Also I would never do 90mm unless using sleeves. Darton makes a sleeve set for going to 90mm in a ford duratec. Virtually same block. I assembled a 12.5:1 8500 rpm dry sumped naturally aspirated motor that had the darton sleeves, The owner had been running the engine for 5 years in rallycross. No issues that I know of.

Its going to cost you the same as it would to buy a new block for the cost of sleeves and machine work.

Why's that? There are a few people i see running .040 90mm pistons. @silvapain being one and i dont believe he had his block sleeved, just bored out .040.

The darton sleeves are stronger and have more material and are going to be resistant to becoming barrel shaped.

I guess it depends on your power goals too, but 8 or so years ago the darton sleeves were made so people could safely go to 90 mm. Iirc when the darton sleeves are bored to 90mm they still have more wall thickness than the oem cylinder wall at stock bore.

Dang man, sorry to hear about this. Found this for, but it MIGHT put you in the same situation. Maybe ask the guy if he would take it to a machine shop to see if a .020 bore will fix it before you buy it?

Disi MZR mazdaspeed 3 6 Engine Block with Crank | eBay

I bought a brand new bare block from Mazda. I am running standard bore pistons, and had no boring / honing done to my block.

I will tale the block to another shop to see about being resleaved. Thanks

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Get a hold of Speedperf6rmanc3 they may be willing to take your block as credit towards a new build.

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I'm in the process right now of just finding a bare block myself. @silverpain; what did Mazda charge for just the block?

I'd love to find a used block/crank combo though.

@silvapain; ^^^

Sent using stupid fucking Swype!

1094 before shipping from Mazda motor sports.

Best source for a bare short block
 

Through MSM it was $1078.01 + $167.21 shipping. The cheapest I found online was $1401.41 + $162.61 shipping through www.onlinemazdaparts.com

The part number is L3K9-10-300H

Anyone have a msm membership to buy through?

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Best source for a bare short block
 

It's not hard to get an MSM membership.

1. Be a member of a competitive car club. A stance, show, coffee meet club won't work. Any club like SCCA, NASA, or the like.

2. Take pictures of your car in the process of being built.

3. Know when you plan on competitively racing your car. It can be drag, road course, Autocross, etc.

4. Go to www.mazdamotorsports.com and apply.

You have to post at least two racing results per year to maintain your membership.

CP offers .040 pistons that you can get 9.5:1 cr. I'm sure there are others too but I don't know of any that offer 10.5:1 besides cp-e.

So there is no one who is running the CPe stage 3 90mm pistons yet?

I'm planning on doing a second build on my engine and raising the CR to 10.5:1 with these 90mm pistons, not sure about
cylinder wall thickness and potential cracking issues associated though.

It's not an issue with the walls cracking. Its with them becoming barrel shaped. The darton sleeves are thicker and should keep this from happening.