91 NA Vert

Compression tested today due to a low unstable idle (around 450-500) and slight white smoke/steam from the exhaust. Front tested good, rear not so much

Front 90,90,90
Rear 80,80,40

These are rough numbers due to using a standard compression tester, however I think it’s obvious enough there’s an issue.

What could my problems be to lose compression on one face? And I know it’s time for a rebuild, what kits or companies that sell them do you recommend?

Right now I’m probably just going to get one of the big sets from Atkins, but I’m open to other options

 

for an n/a the best kit for value i've found is the atkins classic kit no matter what anyone else sais, their semi cast breakable iron seals actually last the longest with the least amount of housing wear second only to factory apex seals. OEM two piece seals are certainly also an option but cost twice as much. ceramics would technically be ideal for a naturally aspirated rotary, but at $3000 for a set of seals alone..... yeah.

if you're certain you did the test correctly, the only thing that can cause a single low compression face is a stuck or broken side seal, which is pretty uncommon.

 

Not sure if this will change anything, but my radiator blew a few months ago and the car did overheat. I was having issue with it prior to this, and it only got to around 220. I read 240 is the temp I should really worry at. Could that heat have cause my irons to swell and crush a side seal maybe?

Also, do you have any opinions on the cryo treated seals from atkins?

 

220F is nothing to worry about.

i have no experience with the cryo seals, just the classic ones and they lasted a good long while in n/a applications.

 

That’s reassuring, I’ve let that 220 number stress me out too much.

Guess I just gotta pull the thing apart to see what’s wrong with it, thank you for the info!

 

Just FYI, but there's a guy on Ebay that rents automotive test equipment. He has RX7 compression tester available for $50 ,for 7 days. Here's the link: https://www.ebay.com/itm/13616607017...Bk9SR6ip-JO5Zg. I've never rented the tester, so I can't comment about his equipment or service. You might want to consider doing a proper compression check before ripping your engine apart.

 

plus $225 deposit and $9 shipping. by that point i think most people would just buy their own tester after the hassle of giving someone $300 with the promise of a refund.

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