So anybody try a wideband O2 on a crossrammed Hemi yet?

[biomedtechguy]

A/F gauge is a tool and not an absolute. Gotta read those plugs!

I'm definitely not arguing against that point, reading plugs is an amazing wellspring of knowledge regarding how the mixture is burning in each cylinder. The tutorials I've seen, where the band/change on the ground electrode falls for example, is really a good bit of info.
The problem I have is pulling the plugs was hard enough on a cold motor in my 70 Roadrunner.
Unless my next ride has more access, and being a drag focused car it may, and the position and angle of the spark plugs may be better on the TrickFlow 270s, but if it's difficult like the Roadrunner was, I honestly can't imagine doing a hot engine plug pull outside in the summer in south Mississippi at night! I could drip so much sweat into the intake I'd hydrolock a cylinder! That's after shutting the engine off at the end of the 1320. I'd need a push or pull to a spot to do the plugs inspection.
That's a LOT to deal with.
The A/F dual wideband O2 system sure does tell a story, like a video instead of a few pictures.
There's a place for both, but I will likely have to rely more on what the O2 system tells me, unless I manage to get easier plug access.

 

[64 Sportfury]

"The Barton intake distribution seems kind of funky."
I believe I read this manifold was an improvement over even the Mopar Performance. Perhaps they were referring to overall performance and not distribution. With the MP cross ram I have unequal distribution and fat idle. I have yet to try transfer slot restrictions with my Holley 770's. I have done a lot of tuning and she runs very well except for the fat idle. I will be watching for your results.

 

[stage3]

I have done a lot of tuning and she runs very well except for the fat idle.

take a look at your idle bleed holes on your metering blocks And Plates, if they r larger than appx .030 the idle will be Excessively rich..

 

[68 HEMI GTS]

"The Barton intake distribution seems kind of funky."
I believe I read this manifold was an improvement over even the Mopar Performance. Perhaps they were referring to overall performance and not distribution. With the MP cross ram I have unequal distribution and fat idle. I have yet to try transfer slot restrictions with my Holley 770's. I have done a lot of tuning and she runs very well except for the fat idle. I will be watching for your results.

I ran the MP intake on the first incarnation of this engine. The distribution seemed better on that one. I’ve been told by a racer who ran both intakes on a high hp 572 that the Barton made around 40hp more on his combo. The plenums are certainly smaller and the carbs sit in different spots slightly with the Barton. As mentioned above you need to dial back the IFR to help the fat idle. If your running a big cam the throttle plates are probably open to the point it pulls on the transfer slots as well at idle. I went to an .028IFR on mine but it was to lean so I went to .031 IFR and added the transfer slot restriction. Really cleaned it up. I have no qualms about drilling and tapping stock metering blocks but as expensive as the 770’s are I went the aftermarket metering block route. I also went to metering blocks on the rear to it uses screw in jets.

 

[Fran Blacker]

I cracked my sexondary's and made them adjustable without removing carbs it helped me clean up idle. Left primary's mostly alone. It's ham and egg compared to 68 Hemi GTX's. The primary meteriing block I plugged the IFR's and drilled .030 holes in plug. Pictures are of secondary mod, 2 things I did to make it work. Thinned the hex down, and ground hump the hex hit not letting secondary's to close. It' only 1/16" down 1/8 dia..Top pic 1/4" wrench on bolt.pic 2 bolts I used, note 2 on right one has a thinner hex. pic 3 red arrow pointing to bolt.

 

[biomedtechguy]

A couple of compliments, an observation, and a question.
Compliments to ALL who wrestle with, mod, and tune multiple carb intakes. Having had the Holley 6bbl modded w/Promax parts and the CORRECT rebuild kits used, along with the awesome NON-STICK reusable bowl gaskets, I had my 6bbl tuned in nicely. Multiple carbs bring the most "OOHs and AAHs" when the hood is popped, certainly compared to one carb intakes. The power and performance is spectacular, especially when you consider the age of the engineering.
Observations:
I want to emphasize that taking my idle advance up to 12°, about 20° with the vacuum applied, and the required mechanical full advance limiter, on a FBO ignition system (FBO Ignition - Home of the HRR688) I had very good performance and most notably the "refinery smell" of unburned fuel was eliminated. Yet another reason why I advocate for the Progression Ignition system, as it is BY FAR the most flexible and advanced ignition system for any carbureated engine.
My question is: "Is anyone on FBBO using a 2x4 EFI/TBI setup on one of the crossram intakes and how is that going?"
Thanks!!

 

[64 Sportfury]

I ran the MP intake on the first incarnation of this engine. The distribution seemed better on that one. I’ve been told by a racer who ran both intakes on a high hp 572 that the Barton made around 40hp more on his combo. The plenums are certainly smaller and the carbs sit in different spots slightly with the Barton. As mentioned above you need to dial back the IFR to help the fat idle. If your running a big cam the throttle plates are probably open to the point it pulls on the transfer slots as well at idle. I went to an .028IFR on mine but it was to lean so I went to .031 IFR and added the transfer slot restriction. Really cleaned it up. I have no qualms about drilling and tapping stock metering blocks but as expensive as the 770’s are I went the aftermarket metering block route. I also went to metering blocks on the rear to it uses screw in jets.

I have .024 IFR's and the idle speed screws are completely backed off so the primary throttle blades are where they are. The blades not as "closed" as I would like but they are untouched. I have added idle air by cracking open the secondaries with limited results. Other than the fat idle, she runs great. Interestingly, there is no rcih exhaust smell. Fran Blacker has been a big help with my tuning these carbs. The cross ram distribution issues ( 2 plugs read a little rich) are something I will live with, short of adding dams to the runners.

 

[68 HEMI GTS]

I have .024 IFR's and the idle speed screws are completely backed off so the primary throttle blades are where they are. The blades not as "closed" as I would like but they are untouched. I have added idle air by cracking open the secondaries with limited results. Other than the fat idle, she runs great. Interestingly, there is no rcih exhaust smell. Fran Blacker has been a big help with my tuning these carbs. The cross ram distribution issues ( 2 plugs read a little rich) are something I will live with, short of adding dams to the runners.

Seems as it has to be getting fuel from somewhere. Cant believe it’ll even start with the .024 IFR.

 

[64 Sportfury]

I agree fuel is getting in somewhere. Maybe my metering block is porous. Can't say. My mixture screws are 3/4 of a turn from the seat, I have reduced the idle airbleed size as well. You have to give it what it wants. Other than the fat idle AFR gauge reading I am happy with it. I look forward to reading about your results.

 

[68 HEMI GTS]

Ran the car over last weekend. Went old school and started really looking at the plugs, the 02 sensor just didn’t seem to be giving me the info I wanted. The cut outs seem to mess with it, especially when they are open. Ended up jetting the carbs down on the primary, car kept picking up. Went until it didn’t make any difference and then went up on the secondary side 2 sizes. Also had one hole running lean, #3. Went to a 74 on the primary that feeds that cylinder and that fixed it. Rest of the primary’s are 72, 74 across the secondary’s. This is on the 770 cross ram carbs. Still running PV’s .080 restriction. Transfer slot restrictors are out as it was too lean after the jet change. Took it for a street cruise today but haven’t pulled my problem child cylinders to see how the cruise looks.

#3 before I jetted back up on that hole.