12a Rebuild

[Dominic]

Cool, think its about time I did an engine rebuild myself. Having sold the rx7 I need a new fix and a 12a/13b rebuild would be a cool project. Then a few years down the line when I have the time, space and money for another 1st gen, i\'ll have a racey little engine to drop in. Think its time I invested in a shed in the garden so I can start tinkering with rotors, dont need much space I guess.

Shaun, are you using the DIY RE dvd\'s or any books etc to help with this project or do you know enough about the engines to just go for it?

[shaunwil]

Er up to now i\'ve not got any dvd or material for the rebuild, Pineapple Racing are doing videos on their webiste at the minute and i\'ll probably buy the DIYRE dvds after xmas.

I\'ve got the factory manual and that does explain how to rebuild an engine. No doubt i\'ll be full of questions in this thread.

Shaun

[Dominic]

Nice one. I\'ll enjoy learning from your mistakes :Giggle  sorry from your experience :cheers

Na seriously, good stuff for posting up the rebuild work. Has inspired me to get going on a rebuild. The good thing about having a heap of time to do it is that I can spread the £££$$$. Hardest decision for me will be injection or carb, but lets not start that debate :chat  

R u gonna do the porting yourself? Would be much more satisfying if you did. I\'m sure there are plenty of knackered old housings available for you to practice on.

If you could keep tabs on rough costs as you progress that would be really helpful.

Cheers

Dom

[shaunwil]

No problem. The housing and rotors hopefully will be checked by WGT and then im leaving it to pip to decide what port will suit what im using the car for.

My biggest decision too is 48IDA webber or gas research carb.

The current engine in the car will be a test bed for a seriously big port, but thats for the future

Shaun

[shaunwil]

Yesturday I got an engine stand and started prepairing the engine for the strip down. Ended up lengthening the slots and grinding the edge of the main plate to bolt the engine too. Ended up having to chisel the flywheel off, only did it in one spot so hopefully it will be salvagable.





With the aid of stu (grinder) I started by removing the oil pan. Then using a 2in wide scraperand hammer i removed the gunk holding the pan onto the bottom of the engine. Cleaning the cavity up gave us this:



Then we drained away any excess oil and swiveled the engine over to the main bolts:



Removing these bolts moving in quadrants and then pulling all the bolts out.

Using a small crowbar to lift the top plate (on parts that arn\'t mating faces) the top iron was lifted off.



Then lifting the rear rotor out (with all the seals falling out of rotor). Then carefully prising the housing off to reveal middle Iron.



From here we had a bit of an issue. When we tried to remove the middle iron we could work out how the e-shaft came out. We lifted the middle iron and the front rotor all in one peice. Then removing the housing. It was then turned over to attack the oil pump housing. Removing the bolts and masaging the housing off with a wooden mallet to reveal this.



Some bits where removed to reveal this:



Then we where left with the e-shaft in the middle housing. The big question is how the he** does this come out Is the e-shaft in 2 peices ??



Then onto the inspection of the housing. The chrome looks seriously worn out and I will some good advice on if they are usable.





All in all a good afternoon, very enjoyable and hopefully it will not need much to go back together. Big thanks to Stu, nice to have him here while we had a fun afternoon !

Shaun

[grinder]

thanks for inviting me - you learn a lot about them - just by seeing the parts in the flesh !

cant wait to put it back together , remove your engine and drop that one in

fun times ahead

[antnicuk]

good work gents, it is very satisfying

i wonder if its the picture, but those exhaust ports look bigger than stock.....

[shaunwil]

Well i\'ve worked out the e-shaft !!! Its a case of lifting and angling the middle iron over the s-shaft and then it comes ok reasonably easily.

Shaun

[stuart wizy]

the front plate should be bolted to stand to fully disasemble the motor.to get e shaft out of middle plate u should leave 1 bolt in stationary gear in the front plate, point the shaft journal to 12 0 clock position and get someone to lift the e shaft up 1" and lift and tilt the plate of the eshaft.
I did it the same way as u on my first time then got the bruce terantine vid which shows u how to do all the nigly bits and stops all the head scratching!!

[shaunwil]

Im not too sure about the ports, they don\'t look like they have been opened out by hand. How big are the ports on a standard 12a ?

Shaun

[mpk490p]

really good to see this, i have a 12a in the garage that was a runner but often thought about giving it a re-build this would really help if it came to that
Mark

[mullins]

You just slide the housings over the eccetric shaft. A little bit of jiggling required. Those rotors look a tad oiled up. Exhaust ports look standard to me.

[shaunwil]

Quick update. Cleaned the rotors up with parafin and a stainless hand brush, removed all the seals and springs and clips. Everything is bagged up awaiting inspection. Will be ringing pip at wgt tomorrow !

Shaun

[Dominic]

Good progress.

Let the porting commence :yes

[shaunwil]

Another Update and its not a good one

Been to wgt for a quick inspection and the housings are junk (already knew this from the loss of chrome) and the rotors are junk too (the groove is too big for the tips). I could rebuild the engine with new parts but it isn\'t really finacially viable.

On a good point i now have quite a few spares and will probably rebuild my spare nikki carb to try and improve my mpg.
Plus i now hae 2 spare gearboxs, a spare alternator and a cleaner airfilter holder

I may rebuild the block just for some practice but it will never fire again !

Probably the option for next year is to buy an 2nd gen egi engine and rebuild and port that and run it on a carb !

Thanks for the interest though !

Shaun