Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: dthebuk on June 06, 2008, 09:18:09 PM

Title: So ive become a "true" 7 owner...
Post by: dthebuk on June 06, 2008, 09:18:09 PM
So after spending £600 on a starter motor, used cat back and compression test.

it turns out that ive got a compression in the front and red rotors between 5.7 and 6.1

So im guessing the engines going to need a rebuild

And to top things off it now sounds like a hoover :\'(
Title: So ive become a "true" 7 owner...
Post by: m1tch on June 06, 2008, 09:33:57 PM
Hmm yeah they are getting low on compression, but remember its best to get the engine rebuilt before the seals go, else it won\'t just be the seals you need to order, but new rotors or housings if the apex seals blow out and damage either, at least you know now :) im gonna get mine done soon, don\'t forget that the FC engine lasts on average 100-125k depending on boost and mods, whereas the FD engine lasts about 75k or so, but I think thats cause its on boost more of the time cause of the twin turbos, more boost = less engine life lol but don\'t forget that as its being rebuilt, now might be a good time to think about porting the engine :)
Title: So ive become a "true" 7 owner...
Post by: m4drx on June 06, 2008, 09:49:58 PM
compression is low but it may not let go for a while.

you did get "mugged off" so to speak on the other items i mean £600 wtf
Title: So ive become a "true" 7 owner...
Post by: m1tch on June 06, 2008, 09:56:03 PM
£600 would probably buy you a washer for a bolt at mazda main dealers lol but I mean if he got a cat back exhaust it might be a good make, i dunno what he got, I need to get my compression done as well, hope mine is a bit higher than that, but yeah hmm
Title: So ive become a "true" 7 owner...
Post by: dthebuk on June 06, 2008, 10:03:28 PM
well the starter was about £200 recon\'d and fitted. The exhaust was about £300 fitted, but it was no bolt on. Then there was about £80 tax and £30 for compression.

Mitch. The engine has done 110k with a rebuild 40k ago (non turbo engine), which means the apex seals have worn down extremely quickly. There\'s also the fact that im struggling to afford the car, let alone the rebuild. Think im going to attempt the rebuild myself, which will take absolutely ages, and then turn it into a track car, i suppose the money i get back on insurance may help with the rebuild, but looks like ill be sharing my sisters car once again
Title: So ive become a "true" 7 owner...
Post by: m1tch on June 06, 2008, 10:06:56 PM
Mate, have a look around at the for sale board, some people are selling blow 13B engines, or even rebuilt engines for less than £3k, which would be cheaper to just drop one of those engines in, of if you are thinking of making a race engine, buy a blown 13B and work on that :) have you got a recipt of where the rebuild was done? was it broken in correctly?
Title: So ive become a "true" 7 owner...
Post by: dthebuk on June 06, 2008, 10:20:02 PM
sorry didn\'t mean to sound angry at you there :P but up set

anyhu, surely buying a blown engine is pointless as mine is probably going to be cheaper to rebuild, which at the end of the day is what i need.

rebuild was done at rotechniks and has made it passed its warrenty 24000miles/ 2 years so there is nothing i can do about it. I have no idea how well it was broken in, there were instructions for it, but no proof.

Looks like a slow rebuild whilst i aquire funds is what im going to have to do. Stripped out and street ported, im sure it would be a laugh :D
Title: So ive become a "true" 7 owner...
Post by: Jit on June 06, 2008, 10:21:53 PM
5.7 to 6.1 at what rpm? I would have thought that the engine shud go on for a bit still with those figures....i drove an FC which had 5.8 - 6.0 all round @250rpm (turbo) for 6 months with no issue watsoever
Title: So ive become a "true" 7 owner...
Post by: dthebuk on June 06, 2008, 10:24:03 PM
RPM isn\'t mentioned, wasn\'t there for the test.
The way i see it, the more its used, the more the rebuild is going to cost, thus it would be cheaper for me to not be insured on it and keep it for a rebuild
Title: So ive become a "true" 7 owner...
Post by: Jit on June 06, 2008, 10:43:15 PM
what dyou mean rpm wasnt mentioned? It should be on your print out. If its turning over slowly then that skews the test results
Title: So ive become a "true" 7 owner...
Post by: dthebuk on June 06, 2008, 10:47:26 PM
Litrally not mentioned.

looks like ill have to ring them on monday.
Title: So ive become a "true" 7 owner...
Post by: pdtaylor18 on June 06, 2008, 10:51:36 PM
easy way out is to add some of that additive to the oil, about £40 a bottle but its contains copper i think and is proven to raise compression in the rotary. Its on ebay somewhere.  If the engine is still starting, running and giving you enjoyment then just save up for the rebuild or do it yourself before the thing blows a tip.  Dont worry about it until the usual starting and running problems arise.
Title: So ive become a "true" 7 owner...
Post by: dthebuk on June 06, 2008, 11:20:27 PM
hmm thanks for the help guys, pete, could you send me a link to this oil additive please?

Ive decided the cars a great little runner and it would be a shame to sacrifice it to a track. so im going to drive it untill my insurance is up, then slowly rebuild it with a cheeky little street port and keep it as a nice daily drive. Even when low on compression its much more fun than a clio.

positive mind ftw :D
Title: So ive become a "true" 7 owner...
Post by: pdtaylor18 on June 06, 2008, 11:38:41 PM
http://cgi.ebay.co.uk/MAZDA-RX7-HONDA-ENGINE-RESTORE-OIL-NEW-LITRE-CAN-nr_W0QQitemZ150214242421QQihZ005QQcategoryZ52640QQrdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

try that, nothing to lose but i really dont know if it has any long term health problems with the engine, be fine if you are pre-mixing.
Title: So ive become a "true" 7 owner...
Post by: Jit on June 06, 2008, 11:54:31 PM
isnt that just really thick oil?
Title: So ive become a "true" 7 owner...
Post by: pdtaylor18 on June 07, 2008, 10:24:26 AM
Ametech Engine RESTORE is the only product that contains the proprietary CSL remetallizing formula. This technologically advanced formulation fills in and seals micro-leaks in the cylinder walls.
NASA developed this proprietary metal treatment lubricant to work in the vacuum of outer space. Now this terrestrial version RESTORES and rebuilds any 4cycle engine from the inside out, within about 500 miles, using CSL(tm) - colloidal molecular sized COPPER, SILVER and ENCAPSULATED LEAD particles (=CSL) carried in a high grade (ASTM)engine oil. These 3 metals are supposed to be in your engine but get worn away by normal friction.

this is just a quote from their site but best to read all the info that they have, as i said it will almost certainly work and not just a quick fix either. however I do not know what affects this will have due to the rotary burning oil.  If you have premix or similar then its not goingto be a problem.  Dont forget this is something to prolong that rebuild even if its just for 6 months, a year or howeverlong it lasts.  For some it might be the easy way out to move the car on.
Title: So ive become a "true" 7 owner...
Post by: colinrx7surrey on June 07, 2008, 04:07:48 PM
The old \'\'nasa developed\'\' this sales trick...
looks intreasting tho pete,maybe it may delay problems from occuring...