Project Fat Nikki
12-01-14, 11:38 AM
#51
Waffles - hmmm good
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First of all, outstanding work.
I do have a few questions. Would you say you are making more power using the nikki versus the Dell ?
Also in comparison to Dell is the nikki is smoother for the street?
I ask because i just built my own 13b using T2 irons with S5 na rotors. Its strictly a Sunday driver cruising winding roads to the mountains, etc. I also have a Dell 48 dcoe to pair with the engine. I am worried as to how smooth a big two barrel could possibly be.
Obviously i dont think a nikki would do me any good because of the lacking cfm i need. However, it does make me wonder about using amother 4 barrel such as a holley.
I too soda blast all my parts before reassembly and i have to say your carb looks fantastic.
I do have a few questions. Would you say you are making more power using the nikki versus the Dell ?
Also in comparison to Dell is the nikki is smoother for the street?
I ask because i just built my own 13b using T2 irons with S5 na rotors. Its strictly a Sunday driver cruising winding roads to the mountains, etc. I also have a Dell 48 dcoe to pair with the engine. I am worried as to how smooth a big two barrel could possibly be.
Obviously i dont think a nikki would do me any good because of the lacking cfm i need. However, it does make me wonder about using amother 4 barrel such as a holley.
I too soda blast all my parts before reassembly and i have to say your carb looks fantastic.
the primaries and secondaries from what I've read. Based on the exhaust smell and color of the
tips of the exhaust its running a bit leaner than the Dell.
Nikki is worlds smoother on the street and probably autox as well. No corner bogs and no initial
bogs down low (<2500 RPM). Nikki seems to scream to redline much easier and feels like it pulls
harder down low as well. Doesn't sound as cool as the Dell.
Having mech secondaries makes it real easy to get decent mileage as well. I easily get 24 mpg
cruising without any problems. City driving might go down to 20 mpg. The Dell if modulated well
would see 26 mpg but city was more like 17 or 18. In the mtns it was around 12
. The nikkistill did about 20 in the mtns.
I think a nikki could be used on that 13B successfully. Maybe Jeff20B will chime in on it.
12-01-14, 01:08 PM
#52
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the best thing about the nikki is that its already setup for the rotary. for mixed street/mountain road use, its also nice its a 4 barrel, this means you can tune for economy on the primaries, and power on the secondaries, and have both.
the 2 barrels are less flexible in the economy department, i think you could do ok, but the driver is probably more important.
the 2 barrel hesitations can be tuned out, but it requires time, and a temporal leap away from the jetting chart you are using. its a funny thing, but when you have a jetting chart, its very hard to realize that your engine, and your gasoline, might be different than theirs, so you may need different jets.
the typical jetting charts are a good starting place, if you're lucky they are very close. if you're unlucky, like me, you need to throw them away and start from scratch.
my P port runs a 2 barrel IDA, and i got that to idle hot and cold, and it pulls cleanly through the rev range with no hesitations, i see no reason why a stock engine couldn't be the same
the nikki on a 13B, if you wanted something that got great economy, and a big fat midrange, but was pretty low revving, then the 13B on a nikki should be fine. the nikki is going to be the airflow limitation, so big power at high rpm isn't going to happen, but big power in the low and midrange could...
the 2 barrels are less flexible in the economy department, i think you could do ok, but the driver is probably more important.
the 2 barrel hesitations can be tuned out, but it requires time, and a temporal leap away from the jetting chart you are using. its a funny thing, but when you have a jetting chart, its very hard to realize that your engine, and your gasoline, might be different than theirs, so you may need different jets.
the typical jetting charts are a good starting place, if you're lucky they are very close. if you're unlucky, like me, you need to throw them away and start from scratch.
my P port runs a 2 barrel IDA, and i got that to idle hot and cold, and it pulls cleanly through the rev range with no hesitations, i see no reason why a stock engine couldn't be the same
the nikki on a 13B, if you wanted something that got great economy, and a big fat midrange, but was pretty low revving, then the 13B on a nikki should be fine. the nikki is going to be the airflow limitation, so big power at high rpm isn't going to happen, but big power in the low and midrange could...
12-01-14, 01:36 PM
#53
Ok, I'll chime in. The Nikki on a 13B can work with varying degrees of success. The best performing Nikki is one that's had its venturis hogged out. The primary venturis are the important ones to enlarge as they are too small at only 20mm from the factory to flow enough for a 13B. They need to be at least 24mm in my experience, and larger if possible (I like my 24.9mm carb for example). The secondaries honestly don't need to be touched in my experience. You also need to do the basics like accel pump mod, mechanical secondaries, probably or definitely remove the choke flap depending, but keep the fast idle linkage. And of course change from the stock air bleeds and jets to something more appropriate on a hogged out carb on a bigger engine. Thus tuning is required.
The result is a carb with better low end torque, still easy to start even without a choke but might need to keep your foot on it while cold (or use the fast idle linkage but I usually don't even bother). The midrange seems noticeably better and the high end is great too. In fact I saw 8 grand on the tach for the first time in this chassis on the fresh rebuild because it went to that RPM much faster than I thought it could. It was a fresh rebuild. Oops.
Oh and it doesn't bog around corners or when you slow down like an Edelbrock oh Holley is known to do.
One quick tip if you're going to hog out a Nikki is get a small drill bit in .045" or .046". Drill out the accel pump nozzle with this size, not Sterling's recommended .050" as that is way too big in my opinion. This .045" drill bit is the 118 I refer to all the time (1.18mm). Also use it to drill out the nickel plated 60s on the secondary slow air bleed location. Transfer these drilled bleeds to the primary side. Then the primary brass slow air bleeds (they range from 150 to 190) need to be filled with solder and installed in the secondary side. The reasons to do this are to 1) bring the idle circuit back into calibration and 2) the secondaries, being mechanical, tend to have a bog or delay caused by too much air and not enough fuel. The filled bleeds reduce this wait time making the carb that much more fun to drive. You might also want to fill the long secondary slow bleeds as well. I did for my boost prepped Nikkis but if you stay NA maybe it's not necessary. Leave the primary long slow bleeds alone.
The result is a carb with better low end torque, still easy to start even without a choke but might need to keep your foot on it while cold (or use the fast idle linkage but I usually don't even bother). The midrange seems noticeably better and the high end is great too. In fact I saw 8 grand on the tach for the first time in this chassis on the fresh rebuild because it went to that RPM much faster than I thought it could. It was a fresh rebuild. Oops.
Oh and it doesn't bog around corners or when you slow down like an Edelbrock oh Holley is known to do.One quick tip if you're going to hog out a Nikki is get a small drill bit in .045" or .046". Drill out the accel pump nozzle with this size, not Sterling's recommended .050" as that is way too big in my opinion. This .045" drill bit is the 118 I refer to all the time (1.18mm). Also use it to drill out the nickel plated 60s on the secondary slow air bleed location. Transfer these drilled bleeds to the primary side. Then the primary brass slow air bleeds (they range from 150 to 190) need to be filled with solder and installed in the secondary side. The reasons to do this are to 1) bring the idle circuit back into calibration and 2) the secondaries, being mechanical, tend to have a bog or delay caused by too much air and not enough fuel. The filled bleeds reduce this wait time making the carb that much more fun to drive. You might also want to fill the long secondary slow bleeds as well. I did for my boost prepped Nikkis but if you stay NA maybe it's not necessary. Leave the primary long slow bleeds alone.
12-02-14, 01:03 AM
#55
I didn't take any pics, but I did a production run of 8 modded secondary main air bleeds to install fuel jets, kinda Sterling style. I had some old school 106 jets from some 74-75 hitachi carbs that got drilled out with my trusty 118 bit. That is the equivalent of about 122-123 main secondary air bleeds! Yay! Now I can do some fine tuning of the secondaries. And I'm not just stuck at around 122ish. I can use just about any size fuel jet as an air bleed you can buy for tuning!
I'm with you on this one Ray. Gotta love the Nikki!
I'm with you on this one Ray. Gotta love the Nikki!
