That is priceless information! good job! I'm going to get a nice variety of carbides & stones and pencil grind away! Glad to see someone that is going all the way with a Cross Fire System! I hope to follow suite! Can't wait for the next video! Thanks dude....luv it.
Great job i picked one of these manifolds up and i really want to port it and try it with a couple Rochester 2 jet 2bbl carbs or even a single 4bbl and a 1/2-3/4” lid spacer
@ thats what i was going to do. Make a lid and a few dif top plates so i could use 2 Rochester 2bbls or 2bbl holleys or maybe 2 2bbl tbi units. 350 tbi units flow 500cfm stock and can flow 650 modified that may be cool with a holley ecm
@glastornjet73 yeah. The only real issue with the CFI units is lack of larger injectors so you're stuck upping pressure to make horsepower. The TBI units having 2 a piece solve that problem. There used to be a kit that would allow the use of a standard Bosch injector in the TBI pod and it would require a different ecm due to the impedance change for the injector. If you are using a Holley unit that may also be an avenue to explore.
@ not anymore you can get big block injectors new again now. Also can get the 9c1 police injectors which are slightly bigger than the regular 350 injectors. The regular 350 injectors are 55lb 55x4=220/8=27.5 thats like having a 27.5lb injector for each hole
Per the gentleman flowing it on the bench, it was aiding flow distribution in the plenum (dead spots) and smoothing flow into the runners. It did pick up CFM with them there.
There's a couple of tricks to make this thing actually flow; one of them is to have the manifold sent off to Extrude-Hone to have the runners smoothed out (once you have it all figured out.) I've ported (and helped others port) more than my fair share of them over the years. You'll want to make a lid spacer (3/8" to 1/2" is good) but at the same time a filler for the middle section where there's no runners will help take up some of the volume increase you get with the spacer. This will help keep the initial acceleration down (more air volume means more air and thus, more fuel needs to be injected.) The spacer will help the fuel flow smoother and distribute more evenly, too. Did you remove the fuel spinners from the lid? Another trick is to mill down some of the bolt bosses where they interfere with the runner opening inside the manifold; use a flat head undercut bolt (similar to what the Renegade uses on their lid.) Note that those crossover ports were primarily in '84 manifolds and not the '82 manifolds from what I saw over the years. The F-body intakes are the same, btw.
The issue I run into is that at half an inch I hit the hood. Seems 3/8 is about the max and IIRC what was found to flow best. We did test without the TB diffusers. We are going to retest with a lid with them still in to see what they do and hopefully use a clear lid to observe smoke flow as well. I have noticed some F-bodies had the early casting intake into 85. Being how old they now are though who knows if someone swapped them though. The increase in plenum volume from removing the EGR passage alone would be difficult to offset imo. I forget if we tried to clay some of the dead space to lower volume.
@@ratherbeboating10 The real problem is fuel distribution, taking the EGR passage out helps with that significantly. The "swirl plates" as we called them back in the day were meant to atomize the fuel better. Of course as you've seen, the runners flow differently - those crossover cuts don't really help much either, they're in the wrong place and a tad too big. Fill in the section between the front and rear runners, you'll recover some of that excess volume you created by having a spacer (that helps fuel distribution.) Remember the EGR passage is hollow and when active, counts as plenum volume. When you get rid of it you create excess volume (but fuel distribution gets better.) If you've ever had the heads off of a stock CrossFire you'd see how bad the distribution is. When I made spacers I made them of phenolic to cut down on heat transfer (cooler denser fuel.) I may still have data from back in the day when I flowed the intake and did all the smoke tests but will take some digging. Best thing is to do like you said, get a clear top and do smoke tests with the TB's installed on top but you'll need to smoke test both at the same time to get a good idea. A good shop vac will provide enough flow for one runner and a smoke test. I tested the Offy (basically the same as the Smokey Ram) when I had it as well, it flowed like crazy but was really overkill for a stock or even slightly modded CrossFire motor. The X-ram had a much smaller plenum volume but the crazy turns and weird restrictions made it not work as great as it could have. (I think I still have one here to play with as a matter of fact.) Feel free to reach out to me on gmail with this name if you'd like more info.
@@thegrumpytexan I will forward this to the gentleman with the flow bench as I'm sure he'd be interested. I am an engineer by trade so i understand this to an extent. But CFD was never something that interested me. So i like to understand how to make it better.... i just don't have the patience to test it on a bench and fine tune. Just don't have the time ultimately. Hence why I'm running a renegade now. Surprisingly enough the fuel distribution on my stock heads wasn't terrible.even running it on the modded engine it was alright but the air demand was beyond a stock engine for sure.
@@ratherbeboating10 Gotcha, my apologies - I thought you were sticking with the CFI manifold. I still have several from the days when I ran the CFI forum with Twinnie. I'll have to give Tom a shout, he bought the HAM board design from our business back in the day; I might want to get one of the EBL systems for mine when I get around to it. Definitely interested to see how that works compared to what we were doing.
@@thegrumpytexan if you talk to Tom, tell him Paul from NJ says hello. And that he hopefully finds his drag radials sooner than later. I wanted to stick with a stock manifold but the port seal on a 1205 leaves little room... just made me nervous. And I don't think any amount of cutting and welding could make it match what that does out of the boc
At the plenum side the majority of the material came from the walls and roof yes. The problem with the floor as I've seen it is in the area you really want to blend down, the casting is at it's thinnest. So by doing the roof at the entrance and floor at the exit I avoided most of the thin area... the walls are quite thick. Recently I worked the floor over further in the runner and just have to finish up and send it out to get reflowed to see how much it picked up... I've opened them all up to the dimensions of the best runner.
I port matched my intake to the heads and did not get them flowed. How much did that cost and who did it for you? I put it on the car an the car is crap until you get to 2500 then it will go.
@@ratherbeboating10 I changed the heads. 64 cc aluminum and 1.6 rockers increased timing to 10degs. Need to check fuel pressure it seems like fuel is puddling at lower rpm. Maybe low vacuum at lower rpm????
@solo_dolo6553 it depends. I still haven't tested it. But on a stock engine it has been reported to be worth up to 7 tenths in the quarter, which is nothing to laugh at.
I found numbers on another bench for an RPM air gap. It's close. We removed the epoxy humps from the inlets and it got better on some ports, worse on others. The clay that is on there was a balance between evening out flow between all runners and max flow possible. We also tried a plenum spacer for the lid and it made almost no difference either way. I know the numbers for the air gap are not apples to apples but the correlation was made based on published numbers for 113 heads. Doug had 113 heads and flowed them and compared them to the published numbers and it was a even 8% lower on his. So we took the super flow numbers on the air gap and adjusted them back. 🙂If I find a cheap enough air gap I'll send it to him for testing too.
That is priceless information! good job! I'm going to get a nice variety of carbides & stones and pencil grind away! Glad to see someone that is going all the way with a Cross Fire System! I hope to follow suite! Can't wait for the next video! Thanks dude....luv it.
I'm trying my best.
Great job i picked one of these manifolds up and i really want to port it and try it with a couple Rochester 2 jet 2bbl carbs or even a single 4bbl and a 1/2-3/4” lid spacer
@glastornjet73 if i were doing that I'd probably just make a custom lid and spacer at that point and move the units to a better location.
@ thats what i was going to do. Make a lid and a few dif top plates so i could use 2 Rochester 2bbls or 2bbl holleys or maybe 2 2bbl tbi units. 350 tbi units flow 500cfm stock and can flow 650 modified that may be cool with a holley ecm
@glastornjet73 yeah. The only real issue with the CFI units is lack of larger injectors so you're stuck upping pressure to make horsepower. The TBI units having 2 a piece solve that problem. There used to be a kit that would allow the use of a standard Bosch injector in the TBI pod and it would require a different ecm due to the impedance change for the injector. If you are using a Holley unit that may also be an avenue to explore.
@ not anymore you can get big block injectors new again now. Also can get the 9c1 police injectors which are slightly bigger than the regular 350 injectors. The regular 350 injectors are 55lb 55x4=220/8=27.5 thats like having a 27.5lb injector for each hole
@glastornjet73 i have the big block injectors and I'm already at their duty cycle limit without really cranking up the pressure.
Great video! Can you explain what the humps are doing?
Per the gentleman flowing it on the bench, it was aiding flow distribution in the plenum (dead spots) and smoothing flow into the runners. It did pick up CFM with them there.
There's a couple of tricks to make this thing actually flow; one of them is to have the manifold sent off to Extrude-Hone to have the runners smoothed out (once you have it all figured out.) I've ported (and helped others port) more than my fair share of them over the years. You'll want to make a lid spacer (3/8" to 1/2" is good) but at the same time a filler for the middle section where there's no runners will help take up some of the volume increase you get with the spacer. This will help keep the initial acceleration down (more air volume means more air and thus, more fuel needs to be injected.) The spacer will help the fuel flow smoother and distribute more evenly, too. Did you remove the fuel spinners from the lid? Another trick is to mill down some of the bolt bosses where they interfere with the runner opening inside the manifold; use a flat head undercut bolt (similar to what the Renegade uses on their lid.)
Note that those crossover ports were primarily in '84 manifolds and not the '82 manifolds from what I saw over the years. The F-body intakes are the same, btw.
The issue I run into is that at half an inch I hit the hood. Seems 3/8 is about the max and IIRC what was found to flow best. We did test without the TB diffusers. We are going to retest with a lid with them still in to see what they do and hopefully use a clear lid to observe smoke flow as well. I have noticed some F-bodies had the early casting intake into 85. Being how old they now are though who knows if someone swapped them though. The increase in plenum volume from removing the EGR passage alone would be difficult to offset imo. I forget if we tried to clay some of the dead space to lower volume.
@@ratherbeboating10 The real problem is fuel distribution, taking the EGR passage out helps with that significantly. The "swirl plates" as we called them back in the day were meant to atomize the fuel better. Of course as you've seen, the runners flow differently - those crossover cuts don't really help much either, they're in the wrong place and a tad too big.
Fill in the section between the front and rear runners, you'll recover some of that excess volume you created by having a spacer (that helps fuel distribution.) Remember the EGR passage is hollow and when active, counts as plenum volume. When you get rid of it you create excess volume (but fuel distribution gets better.)
If you've ever had the heads off of a stock CrossFire you'd see how bad the distribution is. When I made spacers I made them of phenolic to cut down on heat transfer (cooler denser fuel.)
I may still have data from back in the day when I flowed the intake and did all the smoke tests but will take some digging. Best thing is to do like you said, get a clear top and do smoke tests with the TB's installed on top but you'll need to smoke test both at the same time to get a good idea. A good shop vac will provide enough flow for one runner and a smoke test.
I tested the Offy (basically the same as the Smokey Ram) when I had it as well, it flowed like crazy but was really overkill for a stock or even slightly modded CrossFire motor. The X-ram had a much smaller plenum volume but the crazy turns and weird restrictions made it not work as great as it could have. (I think I still have one here to play with as a matter of fact.)
Feel free to reach out to me on gmail with this name if you'd like more info.
@@thegrumpytexan I will forward this to the gentleman with the flow bench as I'm sure he'd be interested. I am an engineer by trade so i understand this to an extent. But CFD was never something that interested me. So i like to understand how to make it better.... i just don't have the patience to test it on a bench and fine tune. Just don't have the time ultimately. Hence why I'm running a renegade now.
Surprisingly enough the fuel distribution on my stock heads wasn't terrible.even running it on the modded engine it was alright but the air demand was beyond a stock engine for sure.
@@ratherbeboating10 Gotcha, my apologies - I thought you were sticking with the CFI manifold. I still have several from the days when I ran the CFI forum with Twinnie. I'll have to give Tom a shout, he bought the HAM board design from our business back in the day; I might want to get one of the EBL systems for mine when I get around to it. Definitely interested to see how that works compared to what we were doing.
@@thegrumpytexan if you talk to Tom, tell him Paul from NJ says hello. And that he hopefully finds his drag radials sooner than later.
I wanted to stick with a stock manifold but the port seal on a 1205 leaves little room... just made me nervous. And I don't think any amount of cutting and welding could make it match what that does out of the boc
That octagon shaped card on a stick you use on the runners,what are the dimension?
1.374x1.058
It doesn’t look like you touched the floors. Was all of the material you removed from the roof of the runners?
At the plenum side the majority of the material came from the walls and roof yes. The problem with the floor as I've seen it is in the area you really want to blend down, the casting is at it's thinnest. So by doing the roof at the entrance and floor at the exit I avoided most of the thin area... the walls are quite thick. Recently I worked the floor over further in the runner and just have to finish up and send it out to get reflowed to see how much it picked up... I've opened them all up to the dimensions of the best runner.
Thank that is awesome work
I port matched my intake to the heads and did not get them flowed. How much did that cost and who did it for you? I put it on the car an the car is crap until you get to 2500 then it will go.
It was only shipping but a gentleman on corvette fourm flowed it... if you look up a flow bench in the C4 section, superl98 comes up.
@@ratherbeboating10 I changed the heads. 64 cc aluminum and 1.6 rockers increased timing to 10degs. Need to check fuel pressure it seems like fuel is puddling at lower rpm. Maybe low vacuum at lower rpm????
@@10rrace it could be any number of things causing that if I'm being honest... puddling and such could be the first place to check.
Also how much did cost you to have the manifold tested? $$ and are you going to modify the throttle bodies?
All I did was pay shipping. He offered his time and the bench as a means to test his machine.
And I have a set of 2 inch throttle bodies already.
Do you still got the ported intake
It's on my work bench. I windowed a section of the runner and haven't gotten around to repairing it yet.
@@ratherbeboating10 would you say its worth my time porting. Only considering doing it because a carb swap is like 400$
@solo_dolo6553 it depends. I still haven't tested it. But on a stock engine it has been reported to be worth up to 7 tenths in the quarter, which is nothing to laugh at.
I wonder how that would do against a 4 barrel intake like a performer. Did y’all test it without the epoxy on the ends of the intake port?
I found numbers on another bench for an RPM air gap. It's close. We removed the epoxy humps from the inlets and it got better on some ports, worse on others. The clay that is on there was a balance between evening out flow between all runners and max flow possible. We also tried a plenum spacer for the lid and it made almost no difference either way. I know the numbers for the air gap are not apples to apples but the correlation was made based on published numbers for 113 heads. Doug had 113 heads and flowed them and compared them to the published numbers and it was a even 8% lower on his. So we took the super flow numbers on the air gap and adjusted them back. 🙂If I find a cheap enough air gap I'll send it to him for testing too.
Just put a single tbi 2bbl. unit on that intake. That’s what I did and makes get power.
Great video! keep em coming :D