Not really an apples to apples comparison to compare the dispacement of the rotary to the a 4-stroke. How do you compare it to a two-stroke the same way?
Ford RX7
- Thread starter BATMANs
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Not really an apples to apples comparison to compare the dispacement of the rotary to the a 4-stroke. How do you compare it to a two-stroke the same way?
I wouldn't compare the rotary to a 2 stroke from the mere principal that the rotary doesn't require a pre-mix oil/gas solution to run.
Ok that's fair but I am talking merely in displacement. The reality is a rotary has three power strokes per revolution as you know. So while compact in overall engine size when compared to a four stroke engine...the reality is it's more like 3 times the displacement...so closer in power to 3.9L four stroke...of course I am sure you have heard this all before.
If you want to think of it a different way, I would compare the mass flow A/F and the power it creates between the two engines and go from there rather than argue the displacement point of view.
I actually think rotaries and RX7's in particular are cool cars...just heard too much feedback about them being in the shop, not running etc..
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- 11 November 2003
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I thought rotaries had a pump which added oil to the combustion chamber to lube the seals? If so, same principal as 2 cycle...
I've heard that argument for rotaries being 2x their piston counterparts, but never 3x.
Yes, you are correct, but it's not always required. I had one clogged up and drove it with no ill-effects for 10's of thousands of miles before including it in a service when I did the turbo and power upgrades.
2 cycle engines have to have a pre-mix or in a short period of time it will seize up before the fuel runs out.
I say 3 because you have 3 power strokes per revolution.
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Wow that's hard to believe - though I don't have much experience with the FD motors, maybe they're different. The early rotaries would lose significant compression if they didn't have well lubricated combustion chambers. I remember my old GF flooding my old carbed 1st gen RX-7 (Badly) and it wouldn't start until I poured a little ATF into the carb to get the seals to hold compression.
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Doesn't require it to run but I've known a few owners who added some sort of oil in the tank at every fill up. Something about helping lube the apex seals. Don't remember what type of oil exactly though. Maybe 2 stroke oil?
There are those that do put 2 cycle oil in their gas tank.
The best part of this post is from 1:20 on...
"at least I can score some hot white girls because I am a brownie"
my friends have called me "Brownie" as a nickname for ages, decades now, I sent this to some of them, oh and my girlfriend they thought it was pretty damn funny.
When all else fails - reference the endowment............
