Few Q's regarding Seal changes, rebuild and intercooler's

[Matt Gibbs]

Hi, i am getting a third gen RX7 type R imported from japan, and for peace of mind i have been thinking is it possible to change any of the seals for new ones without needing to take whole engine apart like coolant seals etc.. so coolant won't get in and need a full rebuild ?

Also if it needs a rebuild i was thinking of putting it in my mates big garage and a few of us rebuilding ourselves with all info we can get off net / advice etc.. and possibly a rebuild video from www.atkinsrotary.com, it seems in theory simpler then a piston engine as it has less moving parts! but i am new to the whole rotary experience. any advice etc..?

Now, intercoolers what are advantages of a SMIC and a FMIC, surely the FMIC are better because they are at the front and so can get more air? or does it make no difference from the SMIC and FMIC ? Can the FMIC's get damaged because of stones etc.. if they at the front ? what performance gains will be achieved from either ? i'm not going to go for HUGE hp as i don't have that muhmoney for tuning but want to get it cooled down etc.. any advice on this aswell!

Just from reading info, looks like the engine isnt reliable at all, with seals always going, engine not lasting long at all always needing rebuilds etc.. as that's what everyone talks about! i know obviously when it's running sweet it is a superb car, but is it worth it due to all engine probs ? or does it really not need rebuilds like every 5k miles as that's what it seems like!

Thanks alot and sorry for the long message
thanks for all your help in advance.

Matt

[mmilner]

Well, nobody has replied to your message. I read it 10 days ago and my initial response would have been:- 'What a load of ...'.

Anyway, I don't know where you got the 5k impression from. We discuss things like seal changes, rebuilds, etc. to let people new to the rotary know about possible pitfalls. (ie: if the engine is old or has been abused, etc.)

The fact is that the older rotary engines will normally last 60K without problems. Newer ones maybe 100K. (These figures are for unmodified engines and vary depending on how the engine/car has been treated.)

My car (Gen 2, 1989, N/A, EGI) had a new engine around 44,000 miles ago and I have not had one problem with it. I have been told by the supplier that the seals should last for around 100k, so obviously shortly before then (if I still own the car) I would be looking to get the seals replaced (refreshed) before I get any problems.

Regards,
Martin.

(ie: The engine IS reliable.)

[maximtaylor]

I'll have a go at the intercooler bit!

Advantages of a front mount intercooler are : lower intake temperatures hence less chance of detonation and more 'bang' through more dense air going in.

Downsides are the cost of the things, moving of compononents to make room (such as moving radiator, smaller batteries, moving or taking out A/c) and the resultant air flow reduction to the radiator from having a big intercooler in the way of the opening.

If you're not really looking to increase hp a great deal you could try a compromise and go for an uprated stock mount intercooler, which are far easier to fit and are supposed to work better than stock ones.

To give an idea of the results of both types, my Apexi front mount cools the air down to 30 degrees celsius tops.

My uprated stock mount used to reach up to 80 degrees celsius on sustained boost. Heat soak at standstill used to be an issue as well, and the stock mount takes ages to cool once it has warmed up.

Hope this is of help.

Regards

Max

[<--rYaN-->]

this mite be a stupid question but i've always wondered....

does water and grit etc getting into front mount damage it at all???

[Fish]

Ryan, yes dirt and grit does get in to the intercooler, but only in the same way as it would get in to the radiator/air con. rad.

What most people do is to put some mesh in front of it to stop the main big lumps like stones, etc. You dont want to get too heavier mesh, as it will restrict the flow of air into the engine bay. I normally try and find something around the 1/2 - 1 cmm hole sized. This seems to be enough to stop the main damaging items.

Another alternative would be to fit something like water injection. This would drop intake temps down to a lot safer level.

Dan

PS. You can get the mesh from most B&Q, Texas, Halford Ripspeed stores.

[johnf]

"Another alternative would be to fit something like water injection. This would drop intake temps down to a lot safer level"


Could you explain this plz - still learning.

[<--rYaN-->]

cheers for that info fish! cleared a thing or two up :D

[Fish]

John, have a look at www.aquamist.co.uk

This is one of the many systems that can inject water into the engine. This cools down the intake temps. much in the same way an intercooler does.

Dan

[Matt Gibbs]

Hey guys, thanks for the info :)
i think whatever a performance car like this wil have problems etc.. so i'm just gonna see how it goes :)
my main mods will be for cooling and fueling to start with no higher boost etc.. as it'll be fast as standard and if i get money for more power later on then that would always be good i just wanna keep her running sweet, ie aquamist.. intercooler, uprated rad, new AST, all new silicone hoses
and vent
should be good :D
thanks for the help :)

Matt

[Fd3BOOST]

Matt, Most coolant seal failures are gonna happen around 60k. Some will live longer than that. Here in the states we only see up to year 95 rx7's. Mazda may have corrected the cooling issues but being that they are most emmisions and turbo related I doubt it. As far as apex seals go. Your not gonna break one in stock trim. If you start modifiny and do not adjust your fuel maps to compensate then your gonna have problems.

All the main seals, (coolant and rotor apex) are in the short block. So yes you have to rebuild the engine to replace them.

SMIC vs. FMIC.
Well it's up to you really, but it's my opinion that a SMIC is less likely to give you cooling issues as it does not block the air from getting to the radiator core.
Alot of drag racers here in the states use FMIC. I do not.
Mounting a FMIC is a major pain in the ass. There is alot of :censored::censored::censored::censored: that you have to cut off the bumper to fit the IC.
A SMIC is pretty much a direct replacement except for a few pipes and a duct that have to be mounted.

-Dave :bandit