New Genuine Mazda block

[Mazduhspeed6]

Ok I am starting to run into some compression issues, but thats for another thread. My question here is, I found one thread on here with a similar question but not has much detail as I per say have. I was looking on REALmazdaparts and mazdapartsusa for genuine mazda shortblocks and heads...the heads are not so much in question here as the blocks. There are a few different blocks linked to different vins...not such a big deal.

My main question is that if there are no differences, besides the revised pistons, are there other revisions I am unfamiliar with; IF there aren't, then why does one short block cost 3,200 and the other cost 2,800. The speed6 block is listed at 3200, the speed3 block is listed below. Is it really just dealers being cocksuckers with their pricing? Secondly and if there are no differences but the pistons, would it suffice to say that itd be better to go with a genpu block with the revised pistons in a speed6, or is there a reason I should stay with the older model block?

Just to state, I dont know if I am doing this yet, just searching my options. I have had 2 reman'd motors lose compression rather quickly, I don't know if its poor assembly and parts or the breakin method. I used 2 seperate methods, the take it easy, low low boost first 500, and the drive it like your going to from the get go, both methods using lots of up and down shifting with engine braking to seat rings.

I used the take it easy method on the first motor which only lasted about 5k and the drive like you plan on it wot pulls from the get go on the second that motor is at about 16k and has started to drop in comp, c1 160, c2 145, c3 140, c4 145. So i am just in a brain fuck right now, i love my car, and have had not a single issue with any thing but the motor itself, nothing else. Soo, anyone with any info pertaining to anything I stated go head and skull fuck my mind with some info, Im ready to learn. Thanks guys, and if this needs to be moved somewhere else, mods please help.

[Pu Manchu]

kinda curious if you did a leakdown on either motor

[Mazduhspeed6]

Yes from leakdown, it seems it's rings. The first block started low to me, 150 exactly across all cylinders, then at the end it was 150, 133, 109, 115. As far as the percentage of leak, I can't remember, but I believe it was almost 50% or more on 1 or 2 of them.

Also is there a reason to your curiosity? Any ideas?

[Fstrnyou]

I think I know the answer, but is it safe to assume that if the compression numbers are good then the leak down would also be good?