Buying advice please

[mattsavage]

Hi. I\'d like some advice please on buying a 2nd gen RX7.
I understand the rotor tips can wear, does a compression test reveal if they are in good condition. If it does what is a \'good\' compression reading?
Are there any other common problems I should look out for?
Would I be best with a turbo or non turbo?
I really want an RX7 as a track day car and to have a blast in the summer!
I\'d appreciate any input.
Cheers,
Matt Savage
 
Derbyshire

[grinder]

crickey - where to begin

a compression test should give you a rough idea of the engine - i think you want a min 85psi on each face ( 3 ) on each rotor ( 2 ) - so 6 figures

if these sets of figure are massively different - then its not in good health

a 2nd gen ( FC ) are renound for rusting - so when you find one - get underneath it and prob the hell out of it - odds are that the engine will be OK and only thin air holding it together

turbo or non-turbo - humm your chouce

i prefer the non-turbo to be honest - as i prefered the drive , but then on the flip side of the coin - the turbo is pretty rapid for a 17yr old car - not a lot of money spent and you will see 200bhp+ at the wheels

make sure all the panels line up correctly ( to to check its not a damaged repaired )

as for rebuild - a turbo one is usally due around the 50K mark , the non turbo can see over 100K if looked after correctly

i cant think of anything else off the top of my head - have a search in the 2nd section - there is LOADS of info in there

Stu

[elford_tim]

Hi Matt,
welcome to the forum. You may actually want to ask your question in the 2nd gen part of the forum .

If you do want an FC track car, I\'d go get a Turbo II - it\'s a lot easier to get more power from that engine than the NA one.

As to compression test results, yes, they can/do reveal to a certain extent if the engine is any good. Before coughing up for a test tho\', I\'d look at the way the engine starts from cold and hot, plus the way it idles.

[grinder]

oppps - moving to correct section

[mattsavage]

Thanks for the info. For the compression check, I guess either spark plug from each rotor is fine?
What are the different model types? I\'ve seen advertised an FC3S, what does this mean?!
Do they all have limited slip diffs?
Cheers,
Matt

[mattsavage]

Hi. How much is a 1991 Turbo II worth in average/good condition?
Please let me know.
Cheers,
Matt

[Brett]

:wave Welcome to MRC Matt.

 FC3S is the start of the vin number for the 2nd gen RX7, its also the model designation used by most rx fans to distiguish between the 2nd and 3rd gen rx7.
 Although some TII\'s came with an LSD they were all friction plate type and I\'ve yet to see one that was still working, so assume that its going to have an open diff.
 The most important thing to look for when testing the compression is that each lobe is producing similar pressure, a differential here can indicate a seal thats worn.  
 A worn engine will usually start fine from cold, but once warmed up it will be a pain to start if left for around 5 minutes. (This is usually a combination of engine wear and old injectors that are leaking into housings after the engine is switched off - in essencence the engine can sort of \'preflood\' itself.)
 A lumpy idle can idicate:-

1) One rotor has lost compression and is not firing correctly. (Engine will seem to shake in the engine bay at idle, probably wont rev beyond 3500rpm either.)
2) Plug leads have been incorrectly connected.

 Check to make sure the car uses oil and shows about 1/5th of the pressure guage at idle and anything upto 4/5th\'s at WOT.  An owner who claims the car never uses any oil probbaly has no idea that they use an oil injection system as part of the sealing/lubrication system. (In many respects its a total losss oiling system that comprises of 4 oil injectors, two short and 2 long as well as the more conventional lubricating functions)

 The brakes are very good, consisting of 4 piston calipers at the front and single piston at the rear.  Seizeing of the rear calipers is common so check its pulling up on both sides at the rear, rear calipers are a bitch to work on.  The fronts are prone to sticking if the car is not subject to constant use. With a bit of time spent lubing and working the pistons in and out most calipers can be returned to full working order.

 Be warned that the TII\'s rust like fury due to being constructed from thinner steel than the non turbo varients, both suffer from rust on the front cross member. (cylindrical, can only be seen from underneath or by peering with a torch in between the rad front of the engine bay.)  Bottoms of the doors and chassis stiffeners are favourites for rust too. (Chassis stiffeners tend to get crushed by idiot el cheapo tyre centres)

 Just to add my 2p on the engine argument, a looked after N/A lump can see over 150K but dont excpet it to last another 2k....90k is more common.  THe turbos can let go at any point between 20k and 90k.  Correct warm up and cool down proceedures along with regular and correct servicing. (Oil filters should be changed every 3000-5000miles depending on how trhe car is used.  Fuel filters are every 15k IIRC)

A good MOT\'d/taxed TII should set you back between £1500-2500.
A ropey TII can be had for as little £1000, but you definately get what you pay for.

 Hope this helps!

 :wave

[mattsavage]

Thanks or the great info, that all makes sense.
For the compression test, with a piston engine I have always removed a plug, cranked the engine, then read the pressure. If I do this with the Rotary engine I will get all 3 figures in one go. How do I test the compression on each side of the rotor?
Cheers,
Matt
 
Just thought, do I put the vehicle in gear, look at the compression gauge and push the vehicle forward whilst looking at the gauge? Would that work?

[sadgoth]

best to have it tested by a rotary specialist as they will have a specific compression tester for rotaries which will give you the 3 seperate readings