Irvine 40 RE

[Andrew Tinsley]

Hello All,
I am interested in finding out which Irvine rear exhaust 40 is the one for using in stunt, on a tuned pipe? I do not have a clue as to how many RE models Irvine made. I see the odd one or two for sale. They are usually R/C carbed engines. I think the correct designation is Irvine 40 RLE, but I wouldn't have a clue as to what one looked like. Is it a special, or is it simply the 40 RE engine converted to C/L?

[Brian Hampton]

This is my 40RLS and from the Ripmax site for Irvine spares it seems that, apart from the red head, the piston, liner (naturally) and wristpin differ from the RC version although in what way I don't know. The RLS is ABC while some of the RC RE Irvines could be either ringed or ABC. Timings are very mild (a little milder than a VF) but having used both the VF and the Irvine I'd say the Irvine is more powerful and gives one flick starts every time if you don't over prime, in which case it'll try to take your finger off . As with the VF, I ran it only on 80/20 all castor fuel. In the photo it's wearing the original Irvine venturi but for flying I used a simple venturi with the needle valve through the crankcase to put the spray bar at a better height for the tank.

[Andrew Tinsley]

Thanks Brian,
So any old R/C 40RE should do, providing that Ripmax have a spare liner! Think that is unlikely but worth a look!

Thanks,

Andrew.

[rustler]

I could be wrong but I think RLS stands for Rear Long Stroke, and it was a dedicated stunt engine.

[BYU]

Hi Andrew

I have used both types myself, the idea of using the Irvine 40 or the OS 40/46 VF was to use them stock on a pipe and low pitch props for a wet 2 stroke run. (no stunt 4-2-4 timing)

The 40 was offered in RLS and RL, both in stunt versions to my knowledge. I have both versions supplied with stunt venturi's. Re Spares I know Mick down in Devon (UK) did stock them as Irvine sold him all their spares at a discount (although I don't know if he is still trading).

[Chris Wilson]

But 13.4 oz with no muffler is a lot for a 40 size engine.

http://www.rcuniverse.com/product_guide/enginespecs.cfm?engine_id=259

Ripmax piston and liner -

http://www2.ripmax.net/Item.aspx?ItemID=X-IRV40RLS-1120&Category=X9051

[Brian Hampton]

I could be wrong but I think RLS stands for Rear Long Stroke, and it was a dedicated stunt engine.

Yep, the RLS was a dedicated stunt engine unlike the VF's which just happened to turn out that way. As for the RLS, the only mention I know of in any magazine was in the June 1996 edition of Aeromodeller where Derek Pickard used one for an article he wrote on piped engines. Derek said it stood for Rear exhaust and Long Stroke but I'm assuming he may have been assuming . Unfortunately Derek gave no more details about the engine other than what prop/pipe/fuel/revs he used. I bought my engine, including prop and pipe, from Derek at the Christmas 1995 Aussie Nationals in Ballarat and AFAIK it's the only one in Australia.



Weight of the Irvine is 11.8 ounces and 40VF is 11.9 ounces, both engines minus venturi/needle valve but both with stub exhaust adaptor and the OS is about 3/16" taller.

[Lauri Malila]

 Hi.

 I've used the .40 RLS a lot in the past and I think that apart from a little difference in power, it's better than .46 VF (stock) that I also used to fly with. Anyway, power was not really an issue, the RLS was just easier to use & adjust.
 The only better thing that I had, was the Irvine .46 RLS. Peter Halman (from Irvine/Ripmax) made me some conversion kits.
 I still have one .46 lying around if somebody is interested.

 Lauri

[M Spencer]

The OS 40 intakes fit in them , H-40 S & FSR S . gotta bittza ringed RE Irvine , not lacking power / rpms , doubt a pipe would be necessary .

[SteveMoon]

Yes, there was a dedicated version of the Irvine 40 RLS motor for stunt.
I used this motor for about 3 season in the mid-90s and really liked it.
It is a rear exhaust, long stroke motor. I used an Aero Products carbon
fiber pipe and header. I was also using the OS 40 VF at the same time
and actually preferred the Irvine, though there was very little to tell
between the two. The Irvine seemed to have a little bit larger power
range. I don't have any scientific proof of this, just my impression after
several hundred flights with each motor. I still have mine and would
recommend it if you can find a good one.

Later, Steve

[Brian Hampton]

I took the head off mine yesterday to measure the bore and stroke which turns out to be the same as the old Irvine 40 Mk III with a bore of 20.55mm and stroke of 19.5mm (.809" and .769") so doesn't seem to be what would be called a long stroke. The curious thing about the parts catalogue is that it shows different P/Nos for the wrist pin for the RC version and the RLS. While I had the head off I checked the compression which is 12.5:1 so very suitable for FAI fuel.

Maybe the RLS stands for Rear exhaust, Low timed, Stunt??

[Chris Wilson]

The liners seem different in the port shape though.

[BYU]

I took the head off mine yesterday to measure the bore and stroke which turns out to be the same as the old Irvine 40 Mk III with a bore of 20.55mm and stroke of 19.5mm (.809" and .769") so doesn't seem to be what would be called a long stroke. The curious thing about the parts catalogue is that it shows different P/Nos for the wrist pin for the RC version and the RLS. While I had the head off I checked the compression which is 12.5:1 so very suitable for FAI fuel.

Maybe the RLS stands for Rear exhaust, Low timed, Stunt??

The engine was in an earlier version R and then changed to RL.

The S stands for stunt, it had a venturi in place of the Carb.

So either 40 RL for R/C or 40 RL S for stunt.

[Andrew Tinsley]

So where does the RE come into this system? I thought that the 40RE was a dedicated R/C engine ? I am getting a little confused. So if both the RL and RE were R/C engines, what is the difference? Just trying to get my head around the variants and it is getting more confusing than I ever expected!

Regards,

Andrew.