Starfox07

The carb is more appealing to me in the end.

And since I've already decided I don't see how EFI discussion is relevant to this thread.

j9fd3s

iTrader: (3)

or there is cruise control and a vacuum switch over there too. i'm not sure off the top, but if you follow it, it should be pretty obvious.

and yeah you could just hook the vacuum advances up to intake vacuum, timing will be more advanced at idle than normal, but that's ok. i'd still tune the carb first, just cause its simpler. one thing at a time

Starfox07

Alright. I'm reading all I can about the DCOE and how to tune it. Anyone have good links? I'm kind of excited about learning the 'forgotten art' of carb tuning, another reason I'm preferring it to EFI at this stage.

j9fd3s

iTrader: (3)

try http://www.expeditionlandrover.info/...erDCOEinfo.htm

rotarycrazy

iTrader: (8)

where are you getting a 48 dcoe from? I am planing on doing a similar setup but also planing on making the 5th and 6th ports work with some solenoids and an rpm switch.

Starfox07

Well I've had to the project on hold until the summer. Unexpected things came up. I've bought the intake manifold and a few other assorted bits, but not the carb yet. Not sure where I will buy from when the time comes.

Starfox07

Resuming this project, still tired of crappy stock EFI.

I'm trying to put together a shopping list of parts:

1. Weber/Dellorto 45/48 Sidedraft
2. Weber sidedraft intake manifold [purchased]
3. Mallory return style FPR
4. Throttle bracket
5. Filter assembly
6. Inline fuel pressure gauge
7. Misc fuel hose

Can you guys think of anything else?

I'm obviously in the market for a sidedraft 45 or 48 carb, so if anyone has one they would like to part with, I'm ready to purchase.

I now have a 2012 Mazda2 which gets 40mpg so gas mileage on my RX-7 is totally irrelevant.

TheRX7Project

iTrader: (3)

I would seriously consider an aftermarket fuel pump and fuel pressure regulator, and a fuel pressure gauge. Good ones. The Summit setup I have was like $100, plus a screw-in fuel pressure gauge which was about $20. Consider it "engine insurance".

Starfox07

Well I have a high pressure fuel pump already (GSL-SE remember) and a Mallory FPR + FP gauge is already on my list.

dbragg

iTrader: (7)

We just did a motor swap in my buddies SE a few weeks ago. Initially it was running on stock motor and FI. We swapped in a ported 4 port and swapped it over to a Dellorto 48.

Here is all you will need (taking into consideration you already have a Weber manifold):

Carb
filter assembly
throttle bracket*
FPR (I highly suggest a Mallory 4309)
FP gauge (get a McDaniels)
a few feet of 5/16" fuel line
*possibly a 12a throttle cable

*The SE throttle cables sheath was too short, but the cable length was fine, for the RB(?) throttle cable on the dellorto. So we just extended the bracket a few inches to fix the problem. Another solution would have been to swap in a 12a throttle cable. This will depend on the throttle bracket you get/make.

Also, if you have a 1 piece Weber manifold, that doesn't utilize the lower stock manifold, then you will need to remove the 5th and 6th ports, which is easy when the manifold is removed. You will also need to make sure your manifold has a nipple for the brake booster, and anything else you want to attach to it (vacuum advance, crankcase vent, etc.)

Then just look under the carpet in the passenger side floor board and you will see a shield held in by four bolts. Remove the shield and it will expose the ECU and other electronic goodies. You can pull the engine harness out through the firewall, disconnect it from everything, and remove it from the car, along with the ECU and everything(it's all attached to one bracket so it's really easy). Now, due to how the GSLSE fuel pump works you will have to bypass the circuit opening relay (I believe is what it's called). It's the only relay you see down there. You just need to put a jumper from the BW and L wires, and they're side by side. Now the fuel pump will come on whenever the key is in accessory, where as it wouldn't before. Dial in your FPR and carb and you're good to go.

I may have forgotten something, but I just recently went through this and it's fresh on my mind, so just ask if you have questions.

Starfox07

Wow. That is a beautiful post. Thank you very much

How is his car running?

dbragg

iTrader: (7)

Awesome. He has been driving it a lot since the swap, about three weeks. I also drove it to his house after the swap, so I got to test it out in the city and on the highway. Honestly, the dellorto was awesome under all conditions, even highway cruising, and would pull hard if you opening it up or just needed to change lanes. It also has an 11 pound flywheel and could use a little tweaking with the tune, so it kind of sucked off the line starting on a hill, but that's the only thing I didn't like. In all other aspects it was just as calm and docile as the FI, but pulled MUCH better when accelerating. Don't forget though, his also came with an engine swap to a 4 port 13b that's street ported and has S5 NA rotors, but I would think you would definitely notice a gain as well.

Depending on how things play out with this wide body SE I have sitting downstairs in my basement, I may be swapping in his old SE 13B and a dellorto relatively soon. If/when I do, I will let you know how it compares.

Starfox07

Awesome. I've also been eyeing the RB 13lb flwheel. If there is one thing I love in this world, it's throttle response.

Starfox07

Would this FP gauge work well? It's the cleanest face I can find, and it's not liquid filled.

Holley 26-500 - Holley Analog Fuel Pressure Gauges - Overview - SummitRacing.com

I would be mounting this in the engine bay, near the carb, correct?

Starfox07

I've located a carb, and it will most likely need to be rebuilt and possibly rejetted. Is the rebuilding something difficult or requiring special tools? I'm pretty good mechanically, so I think I can handle it.

One final question: Will the OMP work just as it did before the removal of the upper intake manifold? I've got a pretty good handle on everything else, but I don't really know about the OMP.






For future reference and anybody stumbling upon this thread via google search or something like that, here is a fantastic source of info on the dellorto 48 DHLA on a stockport 13b:

Gruntled.com - Dellorto - Jetting

13B Instructions

Seems like racing beat did not even bother with the vacuum advance, so I will not either.

j9fd3s

iTrader: (3)

90% of rebuilding the carb is super simple, the hard part is making sure the moving parts work consistently. the weber doesn't really need any special tools, although a little creativity might be required.

the OMP stays untouched with a dell setup, except you need to find a spot for the vacuum feed, if its in the RB instructions just follow that.

for the vacuum advance, i'd leave it like RB has it and then maybe once its tuned try it again

Starfox07

One part confuses me. The lever that connects from the OMP to the throttle body will obviously be different when there is no throttle body. So how will the OMP be controlled? I'm thinking about converting to premix...

edit: Also, I ended up going with a Dellorto and not a Weber. But they are essentially the same from what I've seen.

j9fd3s

iTrader: (3)

i think the RB carbs had the OMP linkage on the carb. or you can use a cable, like a bicycle cable, or premix

i'm pretty sure the dell and the weber are almost the same, i just don't have any recent experience with a dell!

Starfox07

Already ordered an OMP block off plate. I'm tired of looking at that nasty mess at the front of my engine anyways

At some point, I still want to do that rotary aviation oiling system, but at the present time, premix will do nicely. Can't wait to smell that sweet 2 stroke oil

Wow my CC has been getting a workout. Ordered the following in the past two days:

Mallory 4309 FPR [summit]
Professional Products 0-15psi fuel pressure gauge (mechanical) [summit]
OMP block off plate [mazdatrix]
LIM-to-block and UIM-to-UIM gaskets [rockauto]

and a few other things I can't remember :p

j9fd3s

iTrader: (3)

Starfox07

Bought the carb and brought her home. I did a little investigating and it appears to be jetted right on the money for a stockport 13b, right down to the RB specifications. The carb seems to be in good shape, should I rebuild it anyways or try it out as is?

j_tso

iTrader: (2)

At least check the float level and that they do float.

Starfox07

I'm sort of new to the world of carburetors, do I check the float level by attaching the fuel line to the carb and giving it some fuel?

reo

iTrader: (4)

good thread-- 13b with 48 weber sd

j_tso

iTrader: (2)

Hold the top cover up sideways with the hinge on top with the floats closing the needle valve. The needle has a little spring loaded ball, don't have the floats rest on it so much that it's compressed. Then you measure the distance from the floats to the gasket.

Test the floats in a little cup of gasoline. I think Dellortos only had plastic ones, just make sure there are no holes in them.

foxed.ca has a pdf of a rebuid/tuning manual for Weber and Dellorto side drafts, as well as the old How to Modify Your RX-7 which has a nice section for tuning carbs on rotaries.