Pistons/Rod swap without taking block out?
 

Hi guys and Happy New Year for all of you!

I have a friend that swaps pistons and rods in either simple/economic cars like civics and also in small motors like tractors etc, while the block is still in the car. This is very appealing to me because I dont have the money/time/space to pull the whole motor out/machine shop/ etc.

Have any of you guys here ever swapped pistons/rings/rods/bearings with the engine block still in the car?

Thanks for any feedback, Roger

With the miata K member in the way its like going thru the basement to put insulation in your attic, just lots of shit to move to get to the oil pan off. Im also not certain that the pistons will pass thru the bottom end of the block, Many pistons need to be assembled thru the top of the motor with the head off. If your already pulling the head., its less work to pull the entire motor out.

Not a great idea in my book.

Not going to happen, and unless you're using stock or stock size pistons you will have to have the block machined.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Pulling the motor is actually quite easy especially with the tranny attached.

You don't have room for any kind of piston ring compressor with the crank journals in the way. You need to pull it. And as the others said, block will need to be machined.

+1

Not only impossible, but it is so easy to pull a Miata motor that I don't see why you would even consider any other route...

I have rebuilt bp's (using oem size pistons) in fwd applications several times without removing the block. I removed the head to remove and install the pistons and rods and hone the cylinders.

What will you do if you find you must machine or replace the block once in there?

The miata engine bay has way less space to work in as well as the stuff in the way under the oil pan. You won't have an easy time trying to not remove the engine, just rent a picker and get someone to loan you a little space if necessary.

I know this is how most guys do it, but a SM friend of mine swears by just pulling the engine alone. Is it really hard to spline the engine/trans back up with the trans in the car? Harder than other cars? I've done FWD Cadies, FWD Plymouth V6, H2O VW, all with the trans still in the car.

Its just easier to drain the trans,disconnect the PPF and pull the trans with the motor Vs undoing all 18 bolts on your back.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Holy shit, I didnt look at it that way

+1 big time

Said friend owns a dealership, with all requisite lifts, tools, etc. So, probably not apples v oranges.

I don't. Jackstands in my home garage. In the time it takes to get all those damn tranny bolts out you can yank the whole thing.

+1 on pulling the engine and trans as a unit. I even leave my downpipe on, though that may be common practice as well.

I read an article in (IIRC) Import Tuner a long time ago where the guy had called some mobile machine shop guy to come to his house and hone the block in the car. So maybe that guy did it, but it seems to be such a hassle to get the pan off and whatnot you'd be better off pulling the engine.

I leave everything on the car, turbo setup included - ziptie the driveshaft in place and you don't even have to drain the transmission. The two hard parts are getting the tranny turret to clear the lip between the firewall and transmission tunnel and getting the motor to line up on the mounts, but even then it's like a 2 minute holdup for each one of those. It takes Nick and I an hour to remove a Miata motor, working together.

fixed?

Your SM friend is an asshole. He says shit like that so one day, that one stupid dumbass actually attempts it and spends WAY more time/effort than needed looking like a fool.

Ah ha. He may be an asshole, but so am I...

I may think it was a trick if I hadn't been at his shop the other day and saw his car, engine removed, trans still in. He said it took him only an hour, long block out. But again, lift, tools, maybe help from one of his shop techs.

Anyway, do I take the whole ppf out, or just remove the trans/ppf bolts and snake the trans past the ppf?

Amazing how easy it is on this car. I was at it for a couple hours last night, and figure it's half done, working really slow and enjoying the quiet time with a bud light. Nothing like a modern front drive V6/V8!

Sav,

Are you doing this with radiator in or out? I'm about to start my motor swap and would like a few brief tips to make life easy. I was already planning on leaving everything attached (except turbo/intercooler piping, and pull motor with trans. I was going to buy one of those engine leveling contraptions that goes on the picker. Is this thing worth the 30 bucks?