currdog

i just got a 79 sa 12a from japan2la about a month or two ago. i also got a brand new holly 465. other than the secondaries not opening until 6500, the carb works fine. ive done a compression test and it came out fine 95/92 . ive called RB and they said to check for a yellow spring and that is what it has. no vacuum leaks, the right gasket, no spacer. everything is right but the secondaries. they said if it still doesnt work, send it to them. could it be the motor????

Man_in_black49464

iTrader: (1)

i would say the carb the motor is ok compression so get that carb rebuilt or send it back first. Japan2la is a reputable guy he has great stuff so i would trust him but sometimes you get a engine that was bult friday afternoon right before they shift was over ....lol

currdog

alright.... ill just call RB and tell them to send me a shipping tag

Man_in_black49464

iTrader: (1)

are you getting solid power befor the secondaries open?
If you are it has to be the carb if your motor was weak you would have power loss all through the power band.
also the great thing about rotarys is if the compression is bad to effect power it will take forever to start if your engine starts right up you have good compression.

j9fd3s

iTrader: (3)

35 years ago!

um if it compression tests ok, then its not the motor though....

JCurry

iTrader: (6)

currdog is my brother...the engine starts fine every time! two pumps of the gas on a cold day and she fires up. Like he stated under full load in lets say 2nd or 3rd gear the car is lacking in power untill you get to about 6k rpms, at this rpm you can feel the engine come alive and pull very hard to redline..Im guessing the sudden increase in power if from the secondaries opening up...Racing beat says that this car has the correct spring to make the secondaries open up at like 3500 rpms...We have checked everything to no avail!!! they just refuse to come open untill like 6 to 6500 rpms witch is too late!! I dont kno of anything else to try??

Man_in_black49464

iTrader: (1)

if they are mechanical you would neet to shorten the cable to open them sooner if they are vacume secondaries then they need to be plug into a port that sucks -15 at 4500 rpms then they would be wide open but the secondaries might not be -15 type they could be like -20 so the engine needs to build that amount of vacume before the secondaries open

you get my drift?

84stock

iTrader: (5)

Put a 1/4 or 1/2" open spacer under the carb, problem should go away.

JCurry

iTrader: (6)

i was thinking a spacer would work but RB says not to use a spacer at all!

84stock

iTrader: (5)

Your choice who to listen to? I have provided more than a fair share of advice with success with holleys on rotary.

Ask someone else and don't even bother to try then, wtf do I care.

Your response should be, I bought borrowed or found one and it did this for me or that for me.

OneRotor

iTrader: (3)

Just convert from vacuum to manual secondaries. Search for "screw trick" and it will walk you through where to put the screw. It is very easy to do, but it will take some tinkering and a diligent driver to make the most of the mod, but it works like a charm.

I was having the same issue, except most of the time my secondaries on my old RB 465 wouldn't open at all. I did the screw trick and it ran like hell until the motor lost compression (shoddy "rebuild" done by the PO with missing springs).

captainbizzaro

I don't understand this post-he only commented on what RB said he didn't belittle you or openly doubt your suggestion-as far as I could make out it was a simple interaction with you.

JCurry

iTrader: (6)

^^yep wasnt saying your wrong, just stating what RB told me on the phone...they seem to be very strongly against using a spacer but didnt get any solid reason of why...i just called them because after all this carb is 600 bucks new from them!!! but we shall give the spacer a try and if that dosent work them they will go manual...

thanx

Man_in_black49464

iTrader: (1)

I think when RXBOY86 used the !! it was like racing beat said so and thats that so 84 stock is kinda in the right to be upest.

BUT rx7boy86 needs to understancd that hundreds of people have used racing beat carbs and intakes and racing beat has only used maybe 20 different cars. so with differednt engine set ups and people tinkering the hundreds can find a better performance out of the carb and intake and set up,
Ford once told its customers this "With a carburated engine to keep ease of starting in cold weather rev you engine six times and shut the engine off"

just because a company makes it doesnt make it the best possible way to use it.

I am in no way discounting racing beat and there knowlege but technology is changeing and so new ideas and ways of doing things are becoming availible. they have no new products for the rotary and there are a bunch of new things that i have been researching about how to improve the rotary and they are all dont by owners not a company.
It worked in 1990 but they havent changed sence then.

JCurry

iTrader: (6)

^^that was very difficult to read....lol

84stock

iTrader: (5)

Just trust me and try the spacer....

And yeah, it was the "!"

JCurry

iTrader: (6)

will do

thanx

Man_in_black49464

iTrader: (1)

sorry guys i sometimes ramble but did you get what i said?

Keith13b

iTrader: (6)

Call me crazy, but that seems kinda low. I wouldn't expect any major power from a block making below 100 per face. So keep that in consideration.

Man_in_black49464

iTrader: (1)

no doubt its lower then i would like but if it starts right up then its not to the really bad point.

84stock

iTrader: (5)

Yep, you said: "it was the ! and racingbeat blah blah and then old blah blah and I blah blah and try something new"

Had to do it!

JCurry

iTrader: (6)

ok my older brother had a 1" aluminum open spacer...we put that on there and the car did not respond positivly...drive ok with normal driving but upon full throttle it dosent do squat...just completly bogs all the way down will not rev...is 1" too big and would cause my symptoms?? i figured it would of at least drove the same under full throttle but if you punch it it just bogs all the way down and refuses to accelerate...

84stock

iTrader: (5)

Size wouldn't matter much, I am pleased you had a freebie to make the test. Perhaps the rb mods do make a difference, I have seen great success with spacers using off the shelf edelbrocks and holleys on many occasions. Now go back to the carb and it's original installation. Is the check ball present in the secondary diaphragm? If the motor is tired it may not be making a strong enough draw for the vac secondaries (this is also the case if the motor is over carbed with a vac secondary, if you had a 600 cfm this would be exactly the issue. You can still go to a lighter spring yet for the secondaries. Try the short yellow spring or the white one. Here is a excerpt regarding spring calibration on a v8

Next up the vacuum secondary spring rate and when it opens the back barrels with a measured 90% volumetric efficiency on a spintron (reverse dyno).

Holley Vacuum Spring Chart
(Rated from weakest to strongest spring rate)
....................................Holley
Spring............................Part
Color__________________Number
White_________________ 38R-1195
Yellow_________________38R-585
Red___________________38R-552
Purple_________________38R-597
Pink___________________38R-1331
Green_________________38R-515
Orange________________38R-825
Plain (stock)____________38R-464
Brown_________________38R-477
Black__________________38R-684

With a model 3110 (780 cfm vacuum secondary 4150 Holley)
...................................SBC 350......................BBC 402
RPM.........................Tip open ...Full Open.... Tip open ...Full Open
Yellow
(Short Spring)............1620........5680...........1410 .........4960
Yellow........................1635........5750.... .......1420.........5020
Purple........................1915.........6950... ........1680.........6050
Plain...........................2240........8160.. ..........1960........7130
Brown ........................2710........8750.......... ...2380.......7650
Black ..........................2720........can't....... ......2390.......can't

Can't means there isn't enough vacuum in the manifold to overcome spring resistance so the back barrel will never fully open up. Your cam and displacement will effect these numbers so take them as a guideline not as gospel.

84stock

iTrader: (5)

If you have an old nikki kicking around try the spring from it's diaphragm. Another freebie test at least. last of all remove the spring all together, it should bog or if it is tired it still will not open all the way. Do you know the bread tie test?? I would use this to test each spring to see your results.

http://www.youtube.com/watch?v=kXUFwaWo_rQ

JCurry

iTrader: (6)

ok so i drove the car today and did the paper clip mod...i went to 2500 rpms in 1st gear and stomped it, and like i said last night it bogged down real hard...so i immediatly pulled over and the paper clip was moved all the way down...so it seems that with the 1" spacer that the secondaries are fully opening upon full throttle causing the bogg...well i was free reving it in neutral and behold the secondaries open up almost all the was with full throttle off idle!! So im guessing that i either need a stronger spring or a smaller spacer to get the timing just right because with a 1" spacer they just open way too early and too much and immediatly flood the car...any suggestions??