Author Topic: engine stripdown....the rebuilding thread  (Read 687 times)

Offline dubber91

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engine stripdown....the rebuilding thread
« on: August 31, 2006, 12:44:41 AM »
hi guys,

Ive just started to strip down the series 5 turbo 2 motor im planning on fitting into the bug.
I thought it would be a good idea to try and document the happenings during the engine rebuild so i will be getting some pictures of it all shortly. I am by no means an expert but am willing to learn and figure it would be an excellent way of trying to help others out if they are in a similar position: to rebuild or to buy reconditioned.
Its on the workshop bench as we speak and is now in a state that i would consider ready for parts collection and rebuild.
jitesh (one2watch) and I have followed the engine from the point at which it was dropped from the car to the stage at which we are at as we speak. I thank him for his help and correspondence throughout.
Right...so the questions. Having removed all of the parts, i discovered not one, not two, but THREE broken corner seals. What is likely to be the cause of this? Most of the parts seemed to be present (no little peices \'missing\') and thus i hoped the intermediate and end housings would eb OK. As it happens i beleive the end housing is screwed (picture to follow) as there is some scoring to it. how much is allowable?
Further to this there is a slight amount of pitting on the intermediate housing which is very fine....but is it acceptable?
One rotor housing seems good.....no scoring, no serious chrome recession...the other has some scoring and more considerable chrome recession (again not considerable though) what is acceptable here? how much should i pay for a decent second hand one?
I also beleive that the irons may have been ported. Looking at the end irons there is a small \'ground\' edge around the inlet and the edge is not exactly straight from the leading edge of the port to the trailing. Pictures to follow.
What about wall thicknesses? What coolant all thicknesses would you consider to be acceptable? The do vary on these irons but it doesnt seem too considerable...what are the specs?
 Are 13b REW irons the same as turbo 2 irons? and indeed housings? do they differ?
How much can be taken from the motor with buffing the irons? How do you copensate in terms of latteral play?

Thanks in advance for your help guys

Steve

Offline Grizzly

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engine stripdown....the rebuilding thread
« Reply #1 on: August 31, 2006, 08:38:37 PM »
Ok firstly, Do you have a DTI Gauge (Dial Test Indicator) and stand? This is the Gizmo you use to measure the wear in the cast Plates Surface.

The Plates can be resurfaced (Reground) but you\'d have to measure them first to get an idea of the depth to any Scores or Damage. Usaly you will have to Reshim the motor after a Regrind but thats expected in a rebuild anyway.

If you wanted to know if the Plates had been ported usaly the Runner (from the Intake Manifold to the Combustion chamber) would be Smoothed out, if not its usaly a Raw casting type finish.

Fc and Fd Turbo plates are fairly Simalar, The Main diffrence is the Size of the Stock Runners and Ports, If you where to use a pair of Fd secondry plates in your Motor you\'d have to look at moding the Lower intake manifold to mate up to the diffrent plate. TBH as long as your using S5 Turbo Plates i\'d stick with them. BUT!! there is very Little Diffrence In rotor Housings and i\'ve used Fd Rotor Housings in an FC before now (just make sure there matching).

Offline stuart wizy

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« Reply #2 on: September 01, 2006, 07:57:03 PM »
on my fc plates the water jacket thickness wall is 4 times thicker than all my fd engine plates on the bottom, as if the fd wall at the bottom of all plates is a balls up when the recess grooves have been machined in japan! ie not machined to centre of the  casting cause theres loads of thickness at the top and hardly any at the bottom of the plates.
my fc plate water seal walls are probably 4 or 5mm thick at the thinest parts where as the fd ones are less than 1.8mm in places!
the fd engine im rebuilding at the moment blew one of these walls out completely see pic.
bruce terrentine says check wall thickness with a vernier all round your thinest walls and scrap anything below 1.5mm thick and if they are under 2mm thick build them up with some epoxy behind them. Ive had to do this on mine cause the walls are under 2mm thick in places, I will take some pics for u at weekend when i do a bit more cause ive got my rotor and 2 new hosings of tim today so i should be building it back up on sunday hopefully.
Let us know how u go on.

Offline dubber91

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engine stripdown....the rebuilding thread
« Reply #3 on: September 03, 2006, 06:38:36 PM »
ok guys, so what are the limits for scoring on the irons? obviously shimming is relatively easy, and the actual CC wont change will it? I will get some pictures of the engine later

:)

Offline davehg

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engine stripdown....the rebuilding thread
« Reply #4 on: September 03, 2006, 11:43:42 PM »
shimming?????? never heard of it on this type of engine
There are performance cars and then there is the RX-7...........

12.3 second 1/4 mile, terminal speed of 122mph (1st ever drag run on a TO4R)

engine built by....... umm me! now powered by a T51 Kai......

Offline Grizzly

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« Reply #5 on: September 03, 2006, 11:51:52 PM »
Shimming as in the End flote on the E-Shaft?

Offline dubber91

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engine stripdown....the rebuilding thread
« Reply #6 on: September 08, 2006, 09:30:36 PM »
right well it\'ll need shimming now!

Turns out this may be another case of yet another dodgy vendor....

I went round to a learned friends house the other day.....and guy what i found....

The rotors had sustained apex seal damage....obvious from the thickness of the scores and the angle of them. They were cracked.

now this may not seem strange....however, the apex seals were all entirely intact.

I know who the last rebuilders were but in liue of this fact i have decided to stay away from turbing the motor....Im going to combine the parts from the existing 13b and 4 port turbo irons in order to keep costs down and keep it simple. A bridgeport is essential ;)

Steve

ratman38

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engine stripdown....the rebuilding thread
« Reply #7 on: September 10, 2006, 11:23:41 AM »
have got a 92 gen3 rx7 which is starting no prob but after a few mins i have smoke appearing from left side (looking front on) car has had rebuild hope\'ing might b a split pipe just cant see area its coming from anybody any likely ideas before its towed to garage cheers.