Hi; posting here because the system won't let me post in the 'general' area.

I have a 4 port Renesis engine purchased from a recycler. I *don't* have an RX-8 car to use for reference (I'm 'repurposing' the engine in an aircraft.) I need info on routing the smaller coolant hoses, & I'm hoping someone here can help.

I've been told that the ~5/8" diameter port on the rear iron is out to the heater; I assume that one of the 5/8" ports on the water pump return block is the return from the heater. What's destination of the other 5/8" port?

I also need the destinations of the smaller ports:

Small ~5/16" port on top of rear iron?

Small port on top of water pump outlet?

Small ~5/16" port that's T'd into one of the 5/8" ports on the water pump return block?

I also don't have the radiator overflow tank for reference. Does the RX-8 use a pressurized overflow tank (pressure cap on the tank) or a regular unpressurized tank?

Thanks,

Charlie

 

The top one on the rear iron is basically a feed to the throttle body...and an air bleed as it is a high spot. You might want to use that on on a plane as the temp at altitude could warrant it

The overflow is pressurized...and the 5/8 that don't go to the heater go to the tank and return.

there is a shop manual online...someone will post a pick for you I'm sure

Nothing really nontraditional here...it's just coolant

 

Custom intake (no need for broad band torque on a/c), so it sounds like the rear iron tap could go to the top of the overflow tank, along with the small tap on the water pump outlet, right? Any thoughts on the small tap in the water pump inlet? Sounds like I can just cap it.

I've downloaded the shop manual from a couple of sources, but unzipping it just gives me multiple files (hard to read/search). I'll keep looking for a searchable .pdf version.

I really appreciate the help. Knowing that the overflow feeds the extra pump inlet resolved my biggest question.

Charlie

 

You would want the water to go from the outlet on the rear iron to the water pump inlet...with the throttle body inline if you want it kept warm

https://www.rx8club.com/series-i-tec...iagram-183083/ I think those diagrams might help you out


The one from the top of the thermostat goes to the top of the overflow

 

I believe it is never recommended to just cap off a port, as it would create a stagnant area for coolant to pool, better to instead route the rear iron port to the Tstat housing inlet to bypass the TB instead of capping them off.

 

LOL...the amount in the small lines isn't going to be a problem

 

Exactly what I needed. I was unaware of the path through the throttle body & back to the pump inlet. (I've got a block w/o any intake parts.) I'll just plumb it direct, and send the pump outlet tap to the top of the expansion tank, as shown in the drawings.

To Carbon8: I agree about not simply capping ports. The only one I was considering capping was the tap in the pump return for the line through the throttle body; the tap in the rear iron I had tentatively intended to route to the expansion tank. Since the 'stock' path is back to the pump inlet, that's what I'll do. The throttle body I'm using doesn't use or need any heating.

Thanks to you both for your help!

Charlie

 

I'm a pilot and I would be very interested in seeing the finished product.

 

I'll try to get some 'in progress' pics on a site I can link to. There are already quite a few a/c flying with rotaries; most with 13B's, but several with Renesis and a few with 20B's.

Here's a link to the guy who's built most of the reduction drives & engine controllers:

http://www.rotaryaviation.com/

Look at the links on the left side of the page for RVOTTER>4port engine, RVOTTER>renesis, and for the 20B, look at Tests/Projects>RV-8 Project.

If you're interested in seeing more a/c, we can take it off-forum so we don't clog it up with off-topic stuff.

Charlie
mcsophie@gmail.com