yayarx7

This is my first foray into the guts of an engine and I would love some advice from experience.

OK. Here is the situation.

I had a motor with about 40K miles on it and it turned water pumper on me. Whilst I was diagnosing the problem I did a compression check and got Very good compression at both rotors. I pulled the motor apart and from the info I have read it appears to be in very good condition. There are BARELY any marks on the side housings and the oil control rings look good. There is SOME flaking on both of the rotor housings.

I have heard some say that you should replace this that and the other and never reuse such piece and only use this part but I am broke and cheap. (A bad combination) SO, can I just port this sucker out a little bit and buy a gasket/seal kit and put her back together and expect anything to work?(this is the way me and my friends are leaning)

I do NOT need a 100K mile motor but do need a fairly docile one for a daily driver, and I DO want the performance.(too many civic SI’s around that need an old school rotary spanking)

I think I could swing a port job or new apex seals but not both. And I would rather spend that money on a carb upgrade. Or new LCA’s or …well…you get the idea.

I would appreciate any and all comments questions conjectures etc.

Thanks in advance,

jasonred3rdgen

do the porting yourself. just buy the templates from mazdatrix or racingbeat and follow them closely. your CAN do it with a dremmel tool or similiar rotary tool, just be sure to buy the cone shaped expensive bits. the templates will cost about $60.00 for both the intake and exhaust. get a rx-7 workshop manual (chilton or haynes or mazda factory) and check all the specs of the engine (wear of apex groove, side seals etc.). you can use all the old parts just check the length of and pitting of apex seal. your rotor housings seem to be ok as long as the chipping is not too severe. i have rebuilt engines for friends using all their old parts with no trouble. it will just cost the amount of the engine gasket set. i use fel-pro gasket sets for the 12a because they include the oil seal o-rings in the set for about $160. 13b sets are not available from fel-pro. if all parts are ok you should be able to rebuild your engine with all the above included for less than $300. if you need total specifics about rebuilding the engine perfectly let me know, also porting.

fastrotaries

Thanks for all the help.....I'm in on this engine build with him and we just want to make this stuff as cheaply as possible and SPANK some damn Si. We have several motors, so we're bound to get at least one of them right.

Rotortuner

While you are in there buy new corner seal springs, 12 of them cost under 10 bucks and they are definitely worth it. As was alreasy said make sure and put in new oil control O rings. Not the hard rings themselves but just the green rubber ones. I can buy the templates but you realy don't have to. Just take the top up about 3/8 of an inch and the bottom an 1/8 and in up until where the corner seal comes around then smooth it all out. Smooth the inner lip out too. then trace it and duplicate it over to the other 3 ports. Its not that hard to do and many over estimate the difficulty. If you guys have any more questions post on here and we are glad to help.

CJG

Rotortuner

By the way if your only doing a mild street port you shouldn't have to hardly even touch the exhaust ports at all. And use the metal rotary files they work the bast and last longest.

CJG