specialtywoodsjames

I have a 1979 with a street ported 12A and it has the Racing Beat exhaust, intake manifold and the R.B. built Holley 465. I have asked this same question of Racing Beat but have gotten the internet equivalent of a blank stare in return. After a week, they haven't even bothered to tell me that they don't know the answer to my question.

I just bought the car a few weeks ago and when I bought it, it wasn't running so great at low to mid-throttle driving, but it did go like the proverbial bat from hades at full throttle in the upper RPM ranges (4500-7000.) The engine would die at idle when warm (no choke was ever installed so it ran poorly cold, too) so I bumped the idle ever so slightly to keep it running at stop lights. It behaved and smelled like it was running rich and I have nudged down the idle mixture screws a little bit (1/8-1/4 turn?) and tried to make sure they were balanced and now the car drives almost civilized in town.

I have ordered a manual choke kit for it and when I get that I'll get the carb off the car and get down to tuning it more methodically but there is one problem it had when I bought it that it still has. There is a major hesitation in mid right hand corners even at moderate cornering forces and moderate throttle openings. When I say hesitation, I mean it basically stops running momentarily at anything above about 1/3 throttle. The previous owner suggested that it could be an ignition problem, but my gut tells me it's the carburetor. Before I reduced the idle mixture, it seemed that the right hand corners were followed by a choking stink of raw gas for at least a minute following.

The carb is mounted with the float bowls on the sides (primary on the driver's side) and I assume that is the correct orientation given that the oil injection line and linkage looks to be laid out as god intended, though Racing beat is apparently unable to even confirm this basic information. I haven't checked the float levels yet as the only level place I have to work on my car is currently occupied by my friend's Subaru and has been for some time. I have been running the scenarios through my head and there are too many possibilities to narrow it down to a few things to go after. Has anyone else had this problem and is there a known diagnostic path to follow for this particular problem?

Any useful advice would be appreciated.

Cookboy

iTrader: (10)

Try to live with it while you find a Nikki carb and manifold. There are many threads with tips on how to maximize Nikki performance. You'll be pleased.

erick31876

iTrader: (8)

see if it has the center mount floats,if it doesn't that is probably your problem

t_g_farrell

iTrader: (1)

So you didn't buy the carb from RB and expect them to be really helpful on a carb that may or
may not be one they supplied which the previous owner may have foobarred in some as yet
unknown way. I'll give them a pass on this one. I've had a lot of good support over the past
20+ years from them on all of their products that I BOUGHT from them. I understand your
angst but its not their fault they only talk to paying customers, its survival for them.

Search this site using google and the word holley and 12A and see what you come up with.
I know theres a number of things folks have to do to these carbs to get them to behave
correctly on cornering. Even my Dell has issues on right handers because the fuel sloshes away
from the jets in the bowls. A lot of aftermarket carbs have this issue because they end up
mounted 90 deg off of what they were designed for. Only one that don't are the down draft
webers I think. And the Nikkis of course. Cookboy is right on with that advice BTW.

Jeff20B

iTrader: (13)

It's Nikki time!

specialtywoodsjames

"So you didn't buy the carb from RB and expect them to be really helpful on a carb..."

Yes, actually, I do expect them to be helpful. It's called customer service and in every industry I have ever worked in (and there have been a few) it's accorded to existing and potential new customers. Only talking to existing customers isn't survival, it's suicide.[/endrant]

That said, in RB's defense it looks like the tech had responded and the response must have been eaten by my ISP's spam filter, because it never showed up in my email box. I did finally get a response and it was fairly concise and professional, though RB is still refusing to say what the original jets, metering plate/block, powervalves etc. are as they apparently consider that part of their proprietary build system.

I actually still have the Nikki and it's intake manifold. I'll look into sprucing it up and in the meantime, I guess I'll try the center-pivot bowls for the Holley. I was unable to find any information on holley performance under cornering on this forum, but I have never had particularly good luck with the search function on these forums. I'll try using Google instead, that seems like a better option. Thanks t_g_farrell.

specialtywoodsjames

OK, so I have been searching on the carburetor options for the 12A and it has become apparent that most people seem to have the same problems that I have on the RB Holley setup and that there is not likely to be a solution to them, as the Holley, even when mounted in the correct orientation (Which RB didn't do) and even with the center hung floats (a $100+ upgrade) doesn't deliver fuel correctly under cornering nor is it capable of civilized running under normal street driving. However, it seems that all of the threads I have found about the Nikki seem to indicate that the stock nikki can't feed a street port and that I should have mine modified by a guy, who (according to another post) isn't modifying carbs anymore. Does anyone have a specific thread that they think might be helpful for me to read? Thanks again

j9fd3s

iTrader: (3)

you are correct about the holleys, they can be made to run ok in straight lines, but they don't like corners.

if you look into all the Nikki modifications, you'll find that we don't really need "that guy" all the mods are pretty basic. for instance the Rx3 style float is just a replacement part, no magic there. or if you open the throttles and look down the barrels its pretty obvious that the throttle plate screws take up like half the venturi...

the Nikki is nice because its sized and jetted to work on a 12A already, so you can skip the tuning from scratch step

specialtywoodsjames

So I've been searching and reading about Nikki mods 'till my eyes are bleeding and everyone keeps referring to all the good information on pages that no longer exist. Did anyone ever archive Sterling's stuff, for instance?

Cookboy

iTrader: (10)

You can google 'wayback machine sterling metal works' to find his extinct website that has a lot of good info. Most of that is available here in many dozens of threads.
Simply by trimming the boosters and throttle screws greater flow can be achieved. Jets and bleeds can be modified with something like this.



I'm just a cook, but I would start by running the Nikki stock and then modifying as I read more and more threads. Glazedham and Jeff20b, among others, have a lot of carb modding info to be found here.

specialtywoodsjames

Awesome! Thanks for that Cookboy. Also, there is no such thing as 'just a cook'. To be a cook is a fine thing indeed :-)

wankel=awesome

my experience with RB is that they spent a lot of time tuning the Holley, Weber, and Dell setups so they assume they have seen it all.

They dont really have the technical understanding needed to alter the set tune that you get from the factory, at least with the holley's. Common calls to them usually result in "every holley is different", or "they are not quality carbs", or "maybe your engine is junk, because weve been in business 30+ years and everything we sell is fault free."

Is it left turns youre sputtering in? I have heavily modded RB holleys (ironic) that will deal with corners just fine, except for a very hard left corner where the acc pump diaphragm comes uncovered, resulting in a flat spot if the throttle is pumped in said corners.

Although I dont have a good fix for the acc pump issue, the rest are easily dealt with. Appropriate jet extensions, lowest possible fuel jet mods, center hung bowls, and low float levels, ect.

I also saw you mentioned that your idle screws when even dont run very well. Try screwing the idle screw facing the front of the car about a half turn in from where your other screw is. The choke has a "vacuum pulloff" which actually draws idle air through the choke and accounts for about half a turn, and in some cases up to a full turn. (no idea why)

To add to the holley track problems, the way it is mounted isnt really ideal, resulting in a lot of strange issues. Heavy acceleration actually sits the fuel back in the bowl, making rotor 2 have a high float level, and rotor 1 have a low one. decel does the opposite. Just imagine trying to figure in tuning the float slosh and movement when you have problems like that before you even take a turn haha.

Also, via PM I can set you up with the "factory" RB jet sizes and powervalve selections and even air bleed sizes, in case they have been modified. A see a lot of used holleys that have had the air bleed sizes opened up a bit permanently by budding carb tuners, virtually ruining the main body for those without the tools to fix it properly.

t_g_farrell

iTrader: (1)

PM sent to help you out on a nikki if thats your direction.

wankel=awesome

I just read your right hand turning problem... Thats the power valve coming uncovered on the primary side when turning the wheel right.

It took me close to a year to figure that out on one of my own carbs. Theres no fix for it if you keep the power valve. It requires a higher fuel level than usual because its higher up in the fuel bowl. Turning the wheel right will pull the fuel to the outside of the bowl, uncovering both the main jets, AND the power valve.

The only way to combat this is to remove the power valve, and use jet extensions on both sides. I still dont think theres any such thing as a holley power valve extension for sale yet, but it needs invented lol

j9fd3s

iTrader: (3)

+1, its probably best to start even, but then they just need to go where it runs the best, which due to machining tolerances, is probably not going to be even.

wankel=awesome

I actually bought 2 carbs from them, and their customer service was still terrible, and tuning feedback was worse. When I wasn't happy with it I warned others about spending hard earned doe on such an ordeal(naturally). They even went as far as to publicly heckle me here on the forums and slandered my own business through a poster here who was a "friend of the company" because I have constantly reminded the community of how they screwed me with those carb purchases.

Ironically enough, both carbs were discovered to have factory defects, so although the issues werent RB's doing, they certainly didnt take care of it professionally or in a timely manner (at all).

So im 2/2 bad exp with holley feedback and customer relations from RB, specifically. Everything else I ever purchased from them was nice haha. But to throw them a bone, the reason they cant tell you how to fix the carb or jettings or anything else, is because they really dont know it to start with on the sales floor. There might be 1 person who picks up the phone for sales who is even familiar with the product.

I think you should try the nikki, or be prepared to spend $$$ on making the holley worth its weight. It can be done, as I've said countless times here, but its expensive and takes a little bit of fiddling to get right.

DivinDriver

iTrader: (15)

For what it's worth: I've known the RB people personally for quite a number of years. There are three people who primarily 'pick up the sales phones,' plus one more gent who does so on overflow. Two of them have been with the company for longer than I've been buying there (maybe 15 years) & the other two have been there for several years now.

I've spent enough time at their store front (less than a mile from my office) that I've heard them cope with all manner of customer calls, plus all the questions I've brought in myself over the years.

In my humble opinion, their customer service is excellent, and if approached in a courteous and detailed manner I have yet to ever see any of them unwilling to help in any way they can. I've also seen them buck questions to their chief engineer, and also the managing partner, when needful. I've brought them head-scratcher engine internals questions that have ended up with me and their chief engineer spending hours measuring parts - none of which I was charged for, even though I was interrupting 'paying' work.

All I can say is what I've seen, and what I've seen from them has been some of the best customer service I've seen from any speed shop or parts source. They have helped me find products they do not sell, have given me referrals to their own suppliers when things were outside their scope, and have fought with vendors on my behalf over warranty issues that were not really their responsibility (most recently when Tokico's new owners decided to bone their existing customers).

Your mileage may of course vary, but I've never had a bad experience with them in the dozens of interactions and many thousands of dollars I've spent with them.