Randx7

Get blue smoke on startup. It only happens when I start it, and it goes away after a few seconds. I have no smoke when driving.
Could it be the valve seals?
Is it ok to use smoke be gone on an rx7?
I'm using royal purple oil on a non turbo.

Ckforker

Mine has done this since I got it, no oil on the plugs, so it's not leaking at the seals. Are your plugs clean?. I wouldn't use any additives and consider this normal.

NCross

iTrader: (18)

Valve seals?

Randx7

Plugs are clean. I switched back to regular oil and it's much better. It passed smog so I'm ok with it. Thanks for the reply.

Ckforker

I don't think these engines like synthetic, so sounds like you got it fixed with the new oil.

Laf12

Mine smokes up on start too, how much smoke comes out now that you've changed the oil?

Randx7

Barley any smoke comes out on a cold start. I get a little more when it's warm and it's harder to start. I was afraid it would get worse over time but everyone I've talked with seems to think it's nothing to worry about. Changing from royal purple to valvaline 20/50 seems to help. I was told synthetic oils don't play well with rotary engines and I'm inclined to think the same. Are you using synthetic?

NCross

iTrader: (18)

Synthetic is good for roataries when it is a fresh rebuild and you premix only. Using it on a 140,000 mile engine can accelerate problems due to internal tolerance wear. Synthetic is generally thinner than conventional dino oil so it can find its way through the path of least resistance easier and smoke or leak.

Jeff20B

iTrader: (13)

No. Synthetic should not be used in a fresh rebuild because it's too slick. The bearings won't break in properly or it will take a very long time for them to break in.

And I don't know about synthetic being thinner than conventional. Isn't that more to do with the viscosity rating? Like how 5w30 is thinner than 20w50.

You're probably talking about how synthetic doesn't play nice with old hard soft seals.

Randx7

I have a fresh rebuild. It has less than 3000 miles on it. I gotten a lot of opinions and read lots of articles on the subject , but all I know is it smokes

Randx7

less with regular oil.

Jeff20B

iTrader: (13)

The only time I've seen smoke on startup from an engine with such low mileage like yours is when the side plates (irons) were resurfaced or the oil seals were pretty old or the side plates are the early non nitrided from 74-78 or it just needs to break in for a while longer. Just kidding as your break in time is more than long enough. Were the o-rings reused? Were the springs reused? I like to install new competition outer springs in all my rebuilds because they lead to less smoke on startup during break in, even with old but good used oil seals and new viton o-rings from Atkins. I never used resurfaced irons. If I come across a set, I give them to the metal recycler or give them away to anyone who actually wants them. I only rarely use early non nitrided irons in builds these days. I also make sure not to overfill the oil in the pan as that can lead to some smoke.

Was any of this helpful?

Randx7

[QUOTE="Randx7;11892508"]I have a fresh rebuild. It has less than 3000 miles on it. I gotten a lot of opinions and read lots of articles on the subject , but all I know is it smokes[/QUOTE

More with synthetic.

Randx7

Yes very helpful. I switched from synthetic to regular, ran it for awhile and changed the oil and filter again and my smoke problem has gone. The only thing I can think is it was the royal purple. I appreciate all the feedback and don't recommend synthetic oil in rotaries. I was getting worried having such a new build and getting a smoke problem so early on. It passed smog with no problem and the shop (personal friends) saw no smoke on startup and neither did I until I switched to synthetic. It runs so good and I've logged lots of time behind the wheel these passed weeks. Thanks again for all the helpful advice.

rotordogg

iTrader: (4)

Lol, how did Rand escape a verbal beating for that?