Beautiful work of art right there!
Tunnel ram or no tunnel ram...
- Thread starter Miszny
- Start date
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younggun2.0
Well-Known Member
Thanks brother. I have some hours into getting that intake smoothed out
j par
Well-hung Member
That's what these cars are for....
Itch that scratch....
Itch that scratch....
So single carb does not suffer from fuel issues you first mentioned above from being mounted inline straight ahead but dual carbs on a tunnel ram do? Which is it?
Cheapsunglasses
In rust we trust!
Man, if I keep looking at this thread, my car might get a hole in the hood!
Of course there’s some performance benefits of a tunnel ram, but who cares, it just looks cool. Also gives the car a bit of attitude.
Of course there’s some performance benefits of a tunnel ram, but who cares, it just looks cool. Also gives the car a bit of attitude.
j par
Well-hung Member
I just bought a spear hood to cut a hole in and turns out it was better than the hood that was on the car... After sitting in my shed for 7 years now I'm ready to sell that good hood as there's no way I would turn back it's just too fun too cool and I like it too much...Man, if I keep looking at this thread, my car might get a hole in the hood!
Of course there’s some performance benefits of a tunnel ram, but who cares, it just looks cool. Also gives the car a bit of attitude.
Rat Bastid
Dunamis Metron
Did you read what I said? I said I’ve SEEN single 4 carbs turned sideways. I don’t have a CLUE.
I also said my guesses as to WHY they did it were WILD ASSED GUESSES.
That’s what it is.
Yeah, attitude as you whip the Chevy's touches!!!Man, if I keep looking at this thread, my car might get a hole in the hood!
Of course there’s some performance benefits of a tunnel ram, but who cares, it just looks cool. Also gives the car a bit of attitude.
MomsDuster
Well-Known Member
I think he was referring to this quote.
Other than it being physically easier to to tune what are the advantages of sideways mounted vs straight?
I did read what you wrote, but then also said: (Below) This is the confusion. If a single is ok to run standard, why can't you run two? What is the purpose other than some carbs are too long to fit inline? Holley's 660s 4224 carbs were specifically designed for tunnel rams, wouldn't they have made them differently or designed them to mount sideways? It was my understanding it was just the physical size that dictated it.
I agree Mark, I am confused now.
Rat Bastid
Dunamis Metron
Ok, my bad. I think I now understand what you are asking. I apologize.
When running two carbs online, most of the time you are using Holley 4160 carbs because two 4150’s wont physically fit in line. I don’t like that for several reasons.
1. The 4160’s use a metering plate and not a metering block like the 4150. That’s what makes them fit in line. That plate system is thinner.
2. That plate system makes it more difficult to tune the secondary side of the carbs. You can do it, but it is more time consuming and if you make a change that doesn’t work it’s harder to go back to what you had. That’s because for the most part you can’t drill and tap the plate for a brass set screw. You can close a hole you’ve made to big with JB Weld or something and drill it again, but again that’s a PITA if you want to make a quick change.
3. No matter what, if you want to make a change to the secondary side, you have to pull the front carb to get to it. If you want to change something on the primary side you have to pull the rear carb. That’s working to do work you don’t need to if the carbs are sideways.
4. You end up with the little float bowls with side hung floats. There isn’t much you can do with those floats to help with fuel moving to the rear of the bowls. The fuel will stack up at the rear and push the floats up, reducing flow if not shutting the needle and seats off completely.
5. Unless you run 4 primary bowls or maybe you can drill and tap the side hung float bowls (it’s been forever since I’ve even looked at those bowls so I’m going off at least 30 year old memories here) you put the fuel in at the primary bowl and the secondary side gets its fuel through that little tube that runs down the side of the carb.
I take all of that into account when thinking about mounting carbs sideways or in-line. So it’s not just one thing. It’s several.
You would be correct that a single carb, mounted in the front/rear orientation does have the same issues as mounting 2 carbs in line. The fuel runs to the back of the bowl, uncovering the main jets and lifting the float, shutting off the fuel. Same issue for the single and dual four set ups.
There are things you can do to address that in a single 4 like jet extensions. The bigger center hung float bowls have enough fuel volume to help a lean stumble from uncovering the jets with the extensions. If you love dragging the bumper for 300 feet then you have to do some other things. Guys have been modifying, reshaping and reforming floats for longer than I’ve been alive.
When you mount the carb(s) sideways you get the benefits of the bigger float bowls, easy access for tuning changes, secondary metering blocks and you can buy floats that are wedge cut on one or both ends to prevent the float from moving up on acceleration and shutting off the fuel.
If you get the single wedge cut floats (sometimes called “drag” floats) you have to make sure you get a left and right cut float when looking at the float in the bowl.
So the primary side (when looking at the primary float bowl head on) will get left cut floats and the secondary side (again when looking directly at the secondary side) will have right cut floats. If you mix them up, it will make the fuel slosh shut the fuel off because the cut is on the wrong side.
Or you can get the double cut (some call them “road race”) floats so it doesn’t matter which bowl they are fitted to. These double cut floats are also better for street driven tunnel ram stuff because going around a corner can cause enough fuel slosh to shut the fuel off and cause a stumble.
So the short answer is a single 4 has the same issues as in line carbs on a tunnel ram. Which led to my comment about some guys mounting their single 4 sideways. Again, I’m speculating here but I would think that was an effort to help with fuel control issues that couldn’t get fixed by the methods used when the carb is mounted front to rear.
I hope I made that more clear than I did before. Your inference that a single 4 would (and does) have the same issues as in line carbs mounted on a tunnel ram is correct. They do have the same issues. Evidently at some point some guys were turning their single 4 stuff sideways to help combat fuel slosh issues.
Nice billet pair is 2800$-3200$ depending on who you ask. Bigs asked 2790$, I already asked. Also it’s 4-5 weeks waiting time but at this point time is no problem for me.
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Excellent info, thanks.
Thank you and I was fairly confident this was the type of answer I would get and greatly appreciate it. It makes perfect sense for tuning especially during racing. I do have another question though. The front primary bowl is in front of the metering block, fuel pushing back while accelerating would be covering the jets more and the floats then dropping would increase bowl volume during said event....right? It is the rear bowl that would uncover the jets, but in the 4160s there is a metering plate instead. The jet extensions would help more for decelerating in the 4160 whereas the 4150 would need rear jet extensions, i think. Am I confusing this comment " 4. You end up with the little float bowls with side hung floats. There isn’t much you can do with those floats to help with fuel moving to the rear of the bowls. The fuel will stack up at the rear and push the floats up, reducing flow if not shutting the needle and seats off completely.
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My suggestion is get online or call blp and get yourself a couple builder kits, the carbs are f'n sweet and if rat bastid doesn't mind, could you please post a pic of mine. 850 that flows around 1000 cfm, I added 12 hole annulars also.
Rat Bastid
Dunamis Metron
I’ll post a picture of your carb when I get home. The pictures are on my iPad and not my phone.
Talked to BLP also, it’s 3k for 2 carbs but I didn’t ask for builder kits. Many builders use blp billet parts, this applies to my dominator also.
Rat Bastid
Dunamis Metron
Just call and get the builders kit. Here is what a finished BX4 from a builders kit looks like.
Rat Bastid
Dunamis Metron
One of the things that happens to a fluid when it finds a 90 degree wall is the fluid tries to climb the wall. It also finds its way into the corners. If the corners are close together, say in an oil pan or a float bowl, that fluid will also stack up in the corners.
This is why some oil pans that might look good (think box style pans) are really junk unless they have extensive baffling to keep the oil from standing up in the corners on a hard launch. Too bad the butt heads at Stef’s didn’t know this when they built my pan in 1996. Of course, I didn’t know it either and 3 broken rods later I figured it out.
That same thing happens in a float bowl. Once the fuel slams into the back of the bowl (in reality, the fuel remains stationary in the bowl or oil pan and the float bowl or oil pan runs into it) it starts migrating over to the corners.
So the side hung float can still get lifted by the fuel in the corners.
That’s why it’s nice to have the center hung bowls that hold more volume and you can wedge cut both sides of the float.
It makes it so fuel movement doesn’t affect float drop nearly as much.
It's probably no more than $2000 for 2 builder kits & shipping to Warsaw Poland
Here is my old 470. 2/10s faster with it over a M1 and a 1050 dominator. Standard port Stage 6 heads which flowed around 320 and 240. Best run was 10.1 with T ram. 9.03 with nos. Kim
Nice looking stuff Kim, looks like your duster was attempting a Saturn 5 rocket impersonation lol
Actually that is the duster I got the 470 from.
Oh okay, bad ***
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