Lets talk intakes
11-20-2017, 07:49 PM
#1
Lets talk intakes I am currently using a Victor Jr. with an Edelbrock elbow. My issue is that for some reason, all 4 center cylinders show detonation while the outside corners look great. The engine was a SBE 6.0 with an S482. Now its being rebuilt with a forged bottom end so I will be able to turn more rpm now if needed. So I might swap intakes anyone but would rather not spend the money if its not needed.
Anyone hear of this issue before? I always heard that the corners were normally the problem cylinders.
Anyone hear of this issue before? I always heard that the corners were normally the problem cylinders.
11-20-2017, 11:54 PM
#2
What ecu? The corner runners of that intake are quite a bit shorter than the centers. That’s going to lead to the corner cylinders and the center cylinders needing different “tunes” to keep everyone happy. Cost effective but a little bit of work would be to expand the plenum forward and back to make the corner runners the same length as the centers. That would give you consistency between all the cylinders. However, it might move the power up a little bit in the rpm range. The plenum might be too small to be optimum as is anyway. Could be close though taking the elbow into consideration.
11-21-2017, 06:12 AM
#3
MS3 gold box so everything is tunable. Ive just never heard of this problem with them. The elbow is also going to be a lower profile than the low profile I use now. This is due to needing to run the TB through the firewall, so it has to angle down quite a bit.
11-21-2017, 07:57 AM
#5
Just what 3 window said
It's very common for the center 4 to be leaner than the corners on a single plane like that
It's the ditribution imbalance.
Air has mass and velocity entering the manifold, it doesn't want to turn to the corners
It's very common for the center 4 to be leaner than the corners on a single plane like that
It's the ditribution imbalance.
Air has mass and velocity entering the manifold, it doesn't want to turn to the corners
11-21-2017, 08:33 AM
#6
Log shows AFR at 11 to 11.2 at WOT and 20psi. Fuel is C14. Ill most likley go to C16 on the new build.
And on the intake, I understand what your saying. Im going to have it dyno tuned again after the new engine is built so it has a really good baseline. Ill make sure to check every cylinders plugs to tune the inner 4. I was just curious if an intake change may be needed. Or if it was common under boost and I just didnt know about it.
And if money allows it, I want to add an EGT to each cylinder for a little safety. Doesnt hurt to have more readings to look at.
And on the intake, I understand what your saying. Im going to have it dyno tuned again after the new engine is built so it has a really good baseline. Ill make sure to check every cylinders plugs to tune the inner 4. I was just curious if an intake change may be needed. Or if it was common under boost and I just didnt know about it.
And if money allows it, I want to add an EGT to each cylinder for a little safety. Doesnt hurt to have more readings to look at.
11-21-2017, 09:29 AM
#7
The center 4 holes will be leaner. The outer 4 will probably need anywhere from 15+% fuel pulled to clean up the distribution. The Super Vic is a little better than the Vic JR but not much.
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11-21-2017, 12:56 PM
#12
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I always figured there was a reason all the purpose built turbo intakes are forward facing TB's and GIANT plenums. The really fancy stuff even have duel plenums like that modified Hi-Ram that Shearer sells.
11-22-2017, 06:55 AM
#13
I knew about the TB on the face intakes but really didn't know that these were really designed for boost to keep this issue handled. What is the best one in your experience? I may just swap intakes. I have seen the Holley High Ram a lot. Not sure if there is another one that may be better. Also I don't want to spend a crap ton of money on one. I also do not want to run a stock intake. And yes, I've searched this but only find old info from years ago. Maybe something new is out now, or they have change some to make certain intakes better.
Last edited by Taxman20; 11-22-2017 at 07:23 AM.
11-22-2017, 10:18 AM
#16
Could the corners be a problem on a carb setup because they dont end up getting enough fuel? Fuel wouldnt be an issue on an injected motor as they are all getting the same amount, but youre def gonna get more air on the middle guys than the corners, seems logical anyway. As others have said, it can be taken care of with the tune.
11-22-2017, 07:22 PM
#17
Could the corners be a problem on a carb setup because they dont end up getting enough fuel? Fuel wouldnt be an issue on an injected motor as they are all getting the same amount, but youre def gonna get more air on the middle guys than the corners, seems logical anyway. As others have said, it can be taken care of with the tune.
11-23-2017, 07:52 AM
#18
Ill be changing the intake for something that flows equal to all cylinders. It will not be a stock intake but it will not be a 1500+ intake either. Most likely I will get the Holley Hi Ram. I would even consider the Holley Sniper if it woks for a boosted app.
I wont use this Victor Jr. due to the damage it caused my engine. I am sure it helped cause it anyway. After letting the flow issue sink in a few days, yea I can think slow LOL. The damage makes perfect sense. All center rod and main bearings were damaged. One of the center caps was cracked. The crank appears that it had been flexing in the center a lot. The engine is at H Squared Race Engines in Houston and he said the same thing when he saw it. So. If the center cylinders are running lean due to more airflow, then they are seeing more boost pressure. The outer 4 are seeing less boost. So this increases cylinder pressure on the center 4 cylinders so they see much more load and this isn't an equal load on all cylinders which causes the failure I ended up with. So using the tuning to reduce the fuel to the outer 4 cylinders can indeed make the cylinders run equal in AFR, it doesn't make the cylinders run equal loads.
Thanks for the info guys. Im still looking for an intake. If you have info on the Sniper let me know if its any good. I cant find where anyone has used it for boost. Lots of people use the High Ram but the Sniper is lower profile.
I wont use this Victor Jr. due to the damage it caused my engine. I am sure it helped cause it anyway. After letting the flow issue sink in a few days, yea I can think slow LOL. The damage makes perfect sense. All center rod and main bearings were damaged. One of the center caps was cracked. The crank appears that it had been flexing in the center a lot. The engine is at H Squared Race Engines in Houston and he said the same thing when he saw it. So. If the center cylinders are running lean due to more airflow, then they are seeing more boost pressure. The outer 4 are seeing less boost. So this increases cylinder pressure on the center 4 cylinders so they see much more load and this isn't an equal load on all cylinders which causes the failure I ended up with. So using the tuning to reduce the fuel to the outer 4 cylinders can indeed make the cylinders run equal in AFR, it doesn't make the cylinders run equal loads.
Thanks for the info guys. Im still looking for an intake. If you have info on the Sniper let me know if its any good. I cant find where anyone has used it for boost. Lots of people use the High Ram but the Sniper is lower profile.
11-23-2017, 10:53 AM
#19
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Intake Fabrication Hi, Taxman, I made this intake for low hoods. (2004)
The "tech" on the Single Plane intake is INCORRECT.
TRUE, the center runners flow/pulse at different times than the outer four.
The solution is MORE fuel to the outer runners at LOW RPM then less at HIGH RPM. The same with the centers, just the opposite slope which is LESS fuel at lower RPM, THEN MORE fuel as RPM is increased.
This is what MY ECU-882C does with the gain of 20 HP on a 500 HP engine.
Lance
The "tech" on the Single Plane intake is INCORRECT.
TRUE, the center runners flow/pulse at different times than the outer four.
The solution is MORE fuel to the outer runners at LOW RPM then less at HIGH RPM. The same with the centers, just the opposite slope which is LESS fuel at lower RPM, THEN MORE fuel as RPM is increased.
This is what MY ECU-882C does with the gain of 20 HP on a 500 HP engine.
Lance
11-23-2017, 11:16 AM
#20
Ill be changing the intake for something that flows equal to all cylinders. It will not be a stock intake but it will not be a 1500+ intake either. Most likely I will get the Holley Hi Ram. I would even consider the Holley Sniper if it woks for a boosted app.
I wont use this Victor Jr. due to the damage it caused my engine. I am sure it helped cause it anyway. After letting the flow issue sink in a few days, yea I can think slow LOL. The damage makes perfect sense. All center rod and main bearings were damaged. One of the center caps was cracked. The crank appears that it had been flexing in the center a lot. The engine is at H Squared Race Engines in Houston and he said the same thing when he saw it. So. If the center cylinders are running lean due to more airflow, then they are seeing more boost pressure. The outer 4 are seeing less boost. So this increases cylinder pressure on the center 4 cylinders so they see much more load and this isn't an equal load on all cylinders which causes the failure I ended up with. So using the tuning to reduce the fuel to the outer 4 cylinders can indeed make the cylinders run equal in AFR, it doesn't make the cylinders run equal loads.
Thanks for the info guys. Im still looking for an intake. If you have info on the Sniper let me know if its any good. I cant find where anyone has used it for boost. Lots of people use the High Ram but the Sniper is lower profile.
I wont use this Victor Jr. due to the damage it caused my engine. I am sure it helped cause it anyway. After letting the flow issue sink in a few days, yea I can think slow LOL. The damage makes perfect sense. All center rod and main bearings were damaged. One of the center caps was cracked. The crank appears that it had been flexing in the center a lot. The engine is at H Squared Race Engines in Houston and he said the same thing when he saw it. So. If the center cylinders are running lean due to more airflow, then they are seeing more boost pressure. The outer 4 are seeing less boost. So this increases cylinder pressure on the center 4 cylinders so they see much more load and this isn't an equal load on all cylinders which causes the failure I ended up with. So using the tuning to reduce the fuel to the outer 4 cylinders can indeed make the cylinders run equal in AFR, it doesn't make the cylinders run equal loads.
Thanks for the info guys. Im still looking for an intake. If you have info on the Sniper let me know if its any good. I cant find where anyone has used it for boost. Lots of people use the High Ram but the Sniper is lower profile.