My motor = loose butthole
 

I had some issues this weekend with smoke and oil in the engine bay, finally got to look at it tonight and I'm pretty sure my engine is done. Did a compression test and this is what I got:
Cylinder 1: 70 psi
Cylinder 2: 150
Cylinder 3: 145
Cylinder 4: 135

When I pulled the plug in cylinder 4 it was completely covered with oil as well, pictures of my plugs attached in order (or not because of iPad, will upload spark plug from #4 right now)

This is where I need some advice to get me back to tight butthole. The car is a project car I bought for autocross, I enjoy driving it to work when it's nice and on the weekends. The goal with it this year was to drive to autox events within a 150 mile radius of my home. My plan was for a 200-225whp car that was reliable and fun to drive. So my question is where should I go from here? I've purchased good parts when it matters and used parts when they will do. Budget would probably be around $1500 and I am comfortable doing all work myself (besides what needs to be done by a machine shop). So I look for your opinions and advice

#1 plug

#2

#3

#4 again

Probably broke/melted a ringland

Pull the head off

Oil on plug 4 is from a leaky vcg, the issue is #1.

Do the teaspoon of oil test and you'll get a better idea of whether it's rings or valves.

GO! And report back yer findings!

:vash2:

ST 8.5:1 pistons, Eagle rods, valve job, try again.

Agree with flounder, do a wet compression test first. Does not sound like a healthy engine though!

lolol what's the point in any more tests? I mean its clear as day that motor is done.

don't waste time and start rebuilding

If you want to trust it to get you home 150 miles after beating the shit out of it during the day, and you have $1500 budgeted for your engine, then there shouldn't be much of a question. Just look through the build threads of the guys who built their motors and run them at the track. That will tell you what you need and what you don't.

So thinking about this more, rebuild my 1.6 or buy a used 1.8 and put that in instead?

1.6 vs 1.8?


WELL THERE'S A TOUGH CHOICE:giggle:

Well if i go with the 1.8 I would have to wait longer to turbo, would be running just n/a for awhile, or rebuild 1.6 and run turbo and have a fresh motor

worth the wait.

Nothing you say will ever make the 1.Fail be a better option to the 1.8 ;)

That was my orignal thought, replace it now with a 1.8, just the fact of having a refreshed 1.6 over a used high milage 1.8 seems like a better option reliablity wise

Save your Obamabucks and do it right.

I'm pretty sure Obama just takes my money since I have a decent job

Does doing it right mean rebuild 1.8?

Yes. Any less displacement is doing it wrong :party:

Do you guys have a good source for stock rebuilt 1.8l motors? Checked a few you-pull it yards and no miatas around, craigslist has been a bust as well

Unfortunately Miatas are not common in pick-a-part lots, as they usually pay by the pound. The Miata doesn't weigh much, and has lots of valuable aluminum bits.

Herp derp you have a 1.6, my post is useless.

currently have a 1.6l

is eBay my best shot?

Ebay or trolling forums for a part out.

Isn't Planet Miata near you? They often have BPs.

They are close but kinda high and only sell long blocks, not complete assemblies; since I am doing a swap wouldn't it be in my best intrest to buy a complete engine with all sensors, accessories, manifold etc?

Yep it would. :)

Craigslist, local car forums, miata forums, etc. I found mine on a local forum and got to pull it from the car myself. 99 motor with 150k on it for 250 bucks, ran like a champ when i drove it before pulling it and put down good compression numbers. I'm dropping it and boosting it now :)

Decided to go with a 1.8l motor, found one for sale online and purchased it today, should be here the end of next week/early the week after. Now I need to find a new manifold for my setup

Decided to become a 1.8l elitist and because I pulled the motor it made sense to just keep pulling things so this is where I stand now:

https://www.miataturbo.net/attachmen...ine=1365384644

https://www.miataturbo.net/attachmen...ine=1365384644

https://www.miataturbo.net/attachmen...ine=1365384644

My plan from here:
1) Coolant reroute with Begi spacer, kia waterneck and GM big hose
2) Build a manifold similar to what I had but schedule 40 mild steel (Swain Tech white lightning?)
3) Minor wire tuck to clean up engine bay
4) Clean and paint engine bay
5) Patch rust hole in the floor at the passenger side (what gauge material should I use here?)
6) Do some seam welding as outlined in other posts
7) Clean up under dash and wiring, remove unnecessary items (what can I remove if I want to keep just the ability to run the defroster?)
8) Paint passenger area after other items are complete


Those are the items I can think of, anything else you guys wish you had done while it was stripped down? The car is mainly used for fun drives on the street and autox, would like to get into track days and hill climbs down the road