I will amend my previous statement most "off the shelf" holley carbs have a 6.5 afaik
as that is what the holley trick kit rebuild kit comes with aswell by default as the
replacement. I did not intend to mislead anyone. Also on a side note my 12a has a large
streetport so your results may vary. When I bought this engine it was dyno tuned for a
higher altitude and was not aware of the jetting or pvc plug until recently. The power valve
more or less solved my transition issue which had manifested as a starvation issue almost
like a bad fuel pump or clogged filter so again YOUR RESULTS MAY VARY and I in no way
mean to misimform anyone.

 

Wankel this is a great thread. My 85 auto is due for a rebuild this spring and I was to get a brand new Holley 465 set up for it. If I keep all my ports stock (from what I'm reading here) I should be able to bolt on this set up and go...correct? Pardon my ignorance, but what is the advantage of using the "center hung" mod for the bowels?

 

Well, no a normal brand new holley will not work correctly off the shelf. RB modifies the baseplates, air bleeds, jettings, IFR (idle feed restrictions) emulsions circuit, and even the linkage is custom to accept stock 12a throttle cables. Having studied them closely I could easily replicate one of their carbs, but there's an ethics in business morals here.

Your best bet when doing the holley conversion is in fact buying RB's, unless you are very familiar with the carbs and dont mind tinkering. Im old and boring and I didnt want to fiddle with one so I bought a "pretuned" one anyways. I ended up fiddling anyways. Lol.

The function of the center hung bowls is to effectively control fuel slosh in the bowls during cornering and acceleration. Rx7's are light, nimble cars who like being thrown in corners, so it makes sense to have a carb that can take the abuse. The side hung bowls installed on both standard and rb 465's are for very mild driving, and were originally designed by holley for applications that didnt allow the room for the larger, more complex to feed center hung bowls. They have dual inlets, as opposed to the side hungs single inlet and transfer tube. If you run them, you will have to come up with a way to get fuel to both bowls at the same pressure. No small feat without spending money on pretuned "rails" for the inlets.

My carb has QFT aluminum bowls, that feed from either side with float level windows that let you look straight through the fuel bowl. They have foam baffles, road race floats and medium jet extensions on the primary. The secondary is a road race float with a foam baffle as well.

This fully controls the fuel in the bowls, and the center hung are a greater capacity to burn through in a corner that would affect the jets becoming un-submerged, or the needle and seat closed to due inertia holding the float in the upward position. Holley makes spring loaded floats that help fight this and Ive used those too. I have no problems with my holley sputtering in corners, and I have 8 inch wide track radials sticking the car on the inside of most any corner.

Also my RB has the linkage for the auto trans too

 

jetted this down to a 55, and switched to RB dual exhaust. Runs great, but still wont run for **** with the 49 main jet+8.5 power valve that rb installed.

 

double post

 

What set-up you got in there now? Just curious for future referance.

 

RB 465 with AED fuel rail, return regulator, holley blue fuel pump (overkill) power valve plug and jetted it up to 55. Runs fantastic now, tinkered with the float levels too, the primaries like to be a bit higher than the secondaries.

Still running my road race QFT bowls. Damn thing is a rocket with them. .110 spring loaded needle and seats, and QFT road race floats. Im still working with a functional choke, as the heat stove SUCKS. I bought an electric one but I dont like how it heats up the element sooner than the engine is ready. However, I think it is a superior choke even still.

 

Thanks for this. Its good info to have.

 

I will say the electric choke is nice mine too is a bit quick and this thread has become
interesting no bull just good ideas.

 

Yep. I played with the carb some more, still unhappy with its performance off idle. I think im going to trade it for a nice nikki or something more street friendly. This thing makes loads of power, just crappy low rpm performance. It could be that way from the lack of power valve set up, but this thing just doesnt work with one.

 

Well Im sure some of you remember this thread about my brand spanking new RB set up I bought this fall.

The performance of this carb quickly changed from bad to worse, and I did a complete tear down today to visually inspect everything within the carb.

My theory was that for w.e. reason my engine liked different ratios from the carb from one rotor to the other, indicating a bad rotor(or something). RB was sure of this aswell. I took some pics ill put up here later, but here id what im left with.

The throttle shafts and the paths for them withing the baseplate look 40 years old. The pathways are highly chewed up on one side of the carb (firewall side) and are no doubt a vacuum leak. The shafts fit very loosely and one even had a missing nylon bushing. I wasnt aware of RB modifying the baseplates, but whoever caused this damage to the carb knew they did it. The shaft was beaten in there from a tight fit, and in the process probably pushed out one of the bushings. The installer musta just said **** it, because it was left that way INCLUDING the damage they did to the baseplate.

RB denies the "modification" and are putting me financially responsible for the changes made to the carb, and ultimately the entirety of the car from all the parts ive installed to "fix" this problem they have been so sure wasnt their POS workmanship.

I left Jim(T) an email about my disgust with the product, and how long ive dealt with the issue... and the THOUSANDS ive spent to track down the problem through replacement parts and local are shops. 5 months of 11 mpg, maybe dyno confirmed 89 hp, and virtually every part of the engine inspected/replaced.


Take with you what you will from this, but my business with RB is over. This very well could have cost me my engine with the metal shavings and debris falling out of the baseplate over time, as I sure it has been. I have no been able to enjoy my car, much less even drive it to work for 5 months.


If anyone from RB is reading this, please kick your carb modifier in the nuts.

 

Just got off the phone with RB, they told me the only way to fix my car was to purchase ANOTHER rb 465 carb. Not replace it at their cost, mine.

In other words the only way to fix my junk as delivered RB 465 is to junk it and buy a new one for 800$. How can I be the only person that sees im getting ripped off?

 

That whole situation your going through with RB sux in my opinion, why don't you buy another cheap 465cfm Carb and modify it to there specs. Or find another RB 465cfm Carb for cheap. I bought a whole RB 465cfm Carb and intake almost brand new from a member here on the forum for 200.00 and mine runs beautifully. Whatever you decide to do, good luck.

 

Even if I bought a new 465 and did the mods, I still paid for a BRAND NEW rb that should have worked out of the box. Buying a new carb doesnt solve the problem entirely