You make it sound so simple.

So, what's involved in just building the motor with lower compression pistons?

 

My build would include sleeves pistons and rods. It is simple if u have basic knowledge. I just wouldnt take appart a perfect motor just becuse i would want to deck the block too.

 

Ahhh, so the point is a $5000 rebuilt motor is better than a stock one with a head gasket ($300?). I get ya.

Kinda goes without saying though no?

And maybe a little out of some people's league?

 

I never said that was the point. Everybody does different things.

 

Hmmm, well I guess what I'm saying is there's no point.

No point mentioning a $5000 rebuild as an alternative to someones question about a $300 gasket.

Oh, and BTW, I run a 2.4mm headgasket in my current motor and am building another block with low compression pistons so I guess I know what I'm talking about.

 

Or you could just buy FRM compliant pistons for~700

I know most people using the 3mm headgasket have gone through at least 1 gasket so that puts you at about the same price with no where near the reliability or effeciency

 

Such weak sauce... I'm with AusS2000 on this one.

A lot of us can change our own head gasket so there is no expense of labor. In fact, my machinist doesn't charge to check the flatness of a head, so if it is fine I'm out $300 to drop compression.

Unfortunately, unless you're working on a brand new motor it isn't as easy as just swapping pistons. A hone is definitely necessary, and good luck finding someone who can do a good job on frm bores. Labor is a lot more of a hassle too since you'd need to yank the motor and disassemble everything and, at minimum, keep the bearings clean. Most of the guys here aren't that experienced with engine work.

Also, if I were to disassemble the bottom-end I'd feel to the need do it properly. So that adds a micro-polish for the crank and new bearings all over. There is another $400...

For me:

Head gasket swap = 4 hours labor, $300 spent, done same-day.

Replacement pistons = 20 hours labor, $1400 on parts and machining. (Don't forget to include the cost of labor for most guys on here)

Not really an apples-to-apples comparison, which is why the risk of a 3mm is worth it to a lot of guys

 

Just trying to make a point that the next step from a 3mm headgasket is not a $5000 rebuild.

It's also worth noting that honing an FRM sleeve is NOT required unless the bore has been damaged (in which case a 3mm headgasket wouldn't save you that step). Even if you did have to hone it Honda has a bulletin of a step by step how to, if your machine shop isn't competent enough to do it they shouldn't be doing any aspect of a rebuild.

You also can't really through in the cost of the micro-polish and new bearings when you obviously aren't doing those things with the 3mm gasket. That would be along the lines of saying if I was going to take the bottom end apart I would put new connecting rods in too. While I personally would do both and more it doesn't make it relevant.

You can swap pistons in no more than a few extra hours if you pull them out the top and leave the rest of the motor assembled with no more knowledge than changing the headgasket.

 

If you're putting in new pistons you're putting in new rings. If you want them to bed properly you need a hone. If you need a hone you need a diamond honing tool and special coolant in the tank. You can't just whack a honing tool on the end of a drill and wave it up and down.

As for new bearings, whenever I pull a motor down I replace them. As does Momentum, and anyone else who has experience in these things. Hell, if I'm putting $700 worth of pistons in an engine I want it to last a while.