Ultra High Flow, Low Cost, 8V Head Project
12-31-2013, 05:30 PM
#166
Rainman
Rennlist Member
Rennlist Member
You should take a look at how my intake was cut apart. It's clear that it's a simple process to do.
The benefit is that it's still a long runner design, which will clearly spool faster than a custom short runner design.
Plus... the manifolds are cheap and plentiful.
There's a reason they went this route. That said.. it's worth experimenting with.
TonyG
The benefit is that it's still a long runner design, which will clearly spool faster than a custom short runner design.
Plus... the manifolds are cheap and plentiful.
There's a reason they went this route. That said.. it's worth experimenting with.
TonyG
12-31-2013, 05:48 PM
#167
Three Wheelin'
Looking at that and thinking about Patrick's Tilton setup, you lose the giant booster, MC and reservoir. That would open up a lot of room in the engine bay and would allow for a better manifold design for the rear two cylinders. Check out how much real estate you gain!
https://rennlist.com/forums/10142814-post7.html
Relocate the oil fill and dip stick (perhaps between the runners of the new manifold) and you'd have tons of room to play with. Heck, you could probably DIY your own intake if you weld since you'll have gotten rid of all the weird angles.
https://rennlist.com/forums/10142814-post7.html
Relocate the oil fill and dip stick (perhaps between the runners of the new manifold) and you'd have tons of room to play with. Heck, you could probably DIY your own intake if you weld since you'll have gotten rid of all the weird angles.
12-31-2013, 06:17 PM
#168
Rainman
Rennlist Member
Rennlist Member
in a thread i started a few years ago, the possibilities of a remote AOS were discussed and oil filling could be accomplished through the cam tower ports.
taking out the booster really does open up a TON of room...could put the plenum up against the shock tower and have monster, straighter runners.
taking out the booster really does open up a TON of room...could put the plenum up against the shock tower and have monster, straighter runners.
12-31-2013, 07:09 PM
#169
Rennlist Member
Looking at that and thinking about Patrick's Tilton setup, you lose the giant booster, MC and reservoir. That would open up a lot of room in the engine bay and would allow for a better manifold design for the rear two cylinders. Check out how much real estate you gain!
https://rennlist.com/forums/10142814-post7.html
Relocate the oil fill and dip stick (perhaps between the runners of the new manifold) and you'd have tons of room to play with. Heck, you could probably DIY your own intake if you weld since you'll have gotten rid of all the weird angles.
https://rennlist.com/forums/10142814-post7.html
Relocate the oil fill and dip stick (perhaps between the runners of the new manifold) and you'd have tons of room to play with. Heck, you could probably DIY your own intake if you weld since you'll have gotten rid of all the weird angles.
I like the way Corleone did his although might go for longer runners than his.
12-31-2013, 07:31 PM
#170
Race Car
But to Tony's point - if you have itty-bitty short runners that are tuned to hit at 6500 RPM or some other arbitrary point, compared to some with longer runners, you may be giving up 20% VE. That's like discounting how quickly a 3.0L engine would spook the same turbo a 2.5L would.
But at the end of the day, the longer runner intakes will be detrimental to RPM. So you have to design your system properly.
Side note.....about the newer BB turbo's. Has anyone checked out the new Borg Warner EFR turbos? I may be picking up one for my impending build. Ti turbine wheels, unbelievably light.
12-31-2013, 08:08 PM
#171
Rennlist Member
Thread Starter
This is very interesting reading, especially Figure 1. Figure 1 illustrates the effect of intake pipe length on the volumetric efficiency at different engine speeds for a naturally aspirated spark ignition racing engine [Smith 1972]. Notice the dramatic drop off in VE at high RPM with longer runners. The longer the runner, the more dramatic the drop off in VE. This may be a clue to Corleon's very short runner design. Maybe you give up 10% VE in mid-range (I have some to spare 
) and get 20% gain (or more) up top.
http://www.dieselnet.com/tech/air_dynamic-charge.php
Just for reference, the stock intake runner length (including the head port) is about 440 mm. Corleone's intake runner was about 170 mm (including the head port).
Harry, how does turbocharging affect dynamic charging in comparison to an NA?
) and get 20% gain (or more) up top. http://www.dieselnet.com/tech/air_dynamic-charge.php
Just for reference, the stock intake runner length (including the head port) is about 440 mm. Corleone's intake runner was about 170 mm (including the head port).
Harry, how does turbocharging affect dynamic charging in comparison to an NA?
01-01-2014, 10:56 AM
#172
That is a good graph, and it goes along the lines of what I was thinking the other day - the higher the value on the torque scale, the lower the acceleration of the engine past this peak torque. The ram effect creates a virtual point of inertia that will be "harder" to cross the longer the runners.
My intake uses ~220 mm runners. I think the Lindsey's is the same.
170 mm is IMO too short for the stock valve train, and would require a dry sump to rev the engine where such a short length should show its true benefits.
My intake uses ~220 mm runners. I think the Lindsey's is the same.
170 mm is IMO too short for the stock valve train, and would require a dry sump to rev the engine where such a short length should show its true benefits.
Last edited by Thom; 01-01-2014 at 11:12 AM.
01-01-2014, 07:44 PM
#173
Three Wheelin'
how about taking 2 stock manifolds and cutting them down the plenum like yours, but with the cut line offset to one side on one, and to the other on the second manifold, then join them together to make a bigger plenum? youd need a bigger throttle to fit the now-oval opening, but could be a cheap way to handle more air.
01-01-2014, 09:53 PM
#174
Rennlist Member
Thread Starter
I am fairly certain the long runners are limiting my performance above 5500 rpm. I am looking at something like shown below, short runner, large plenum, and a bolt in replacement using parts of the stock intake. How short of runners is still a work in progress. It will incorporate some kind of bellmouth and the runners will be replaced with aluminum tubing.
01-02-2014, 02:52 AM
#175
Rennlist Junkie Forever
The turbo engine is a N/A engine until the turbo spools. Thus the runners can be used to get the VE up at around 500rpms before turbo spools.
This increases the power, which increases the exhaust gas, just as the turbo is starting to spool.... which results in a turbo that spools sooner than would the same turbo with short runners.
That said, the object is to use runner length to accomplish this while making sure that the runner itself isn't hurting power up top which is done by making sure that the intake port in conjunction with the intake runner both together flow enough CFM to support the power level you're targeting.
These are low reving engines. None rev and make power up high like a 4 liter Cup engine (which is at 8500-9000 rpms). And the Cup engines don't even use intakes with tiny runners.
TonyG
This increases the power, which increases the exhaust gas, just as the turbo is starting to spool.... which results in a turbo that spools sooner than would the same turbo with short runners.
That said, the object is to use runner length to accomplish this while making sure that the runner itself isn't hurting power up top which is done by making sure that the intake port in conjunction with the intake runner both together flow enough CFM to support the power level you're targeting.
These are low reving engines. None rev and make power up high like a 4 liter Cup engine (which is at 8500-9000 rpms). And the Cup engines don't even use intakes with tiny runners.
TonyG
This is very interesting reading, especially Figure 1. Figure 1 illustrates the effect of intake pipe length on the volumetric efficiency at different engine speeds for a naturally aspirated spark ignition racing engine [Smith 1972]. Notice the dramatic drop off in VE at high RPM with longer runners. The longer the runner, the more dramatic the drop off in VE. This may be a clue to Corleon's very short runner design. Maybe you give up 10% VE in mid-range (I have some to spare ) and get 20% gain (or more) up top.
http://www.dieselnet.com/tech/air_dynamic-charge.php
Just for reference, the stock intake runner length (including the head port) is about 440 mm. Corleone's intake runner was about 170 mm (including the head port).
Harry, how does turbocharging affect dynamic charging in comparison to an NA?
) and get 20% gain (or more) up top. http://www.dieselnet.com/tech/air_dynamic-charge.php
Just for reference, the stock intake runner length (including the head port) is about 440 mm. Corleone's intake runner was about 170 mm (including the head port).
Harry, how does turbocharging affect dynamic charging in comparison to an NA?
01-02-2014, 06:49 AM
#176
Rennlist Member
True enough but what about when you're on the track or very spirited driving and seldom below 4000rpm? Shifting the power across to the rhs will only be beneficial if we can push through the 6k ceiling. I am hopeful that between us we can find a useful compromise that proves superior than the stock intake without sacrificing any semblance of mid range whatsoever.
01-02-2014, 07:10 AM
#177
Addict
Rennlist Member
Rennlist Member
What about resonance intake tuning like this?
http://www.downingbrothers.com/super...ke-runners.htm
Document with a lot of technical information on the subject: http://nwmobilemechanicdotcom.wordpr...search-papers/
Although not a technical supercharger, tuned intake runners can increase the VE of an engine past 100% under certain conditions. The secret to tuning intake runners is utilizing and understanding the pressure waves inside the intake of an engine. Pressure wave tuning can be understood in a few steps, depicted as follows:
1 The air (indicated by blue) flows into the combustion chamber at a high rate of speed.
2 The valve snaps shut (drawn in grey), and the air's momentum still carries it down the intake runner. The air piles on top of itself creating an area of high pressure near the valve.
3 The high pressure wave travels back up the intake runner.
4 The wave hits the plenum wall. Some pressure escapes into the plenum.
5 Most pressure is sent back down the intake runner.
6 The pressure wave arrives back at the intake valve as the intake valve opens. This effectively 'supercharges' the intake and drives air into the cylinder.
(note: the pressure wave bounces between the plenum wall and the valve more than once unless the intake runner is 10 feet long)
1 The air (indicated by blue) flows into the combustion chamber at a high rate of speed.
2 The valve snaps shut (drawn in grey), and the air's momentum still carries it down the intake runner. The air piles on top of itself creating an area of high pressure near the valve.
3 The high pressure wave travels back up the intake runner.
4 The wave hits the plenum wall. Some pressure escapes into the plenum.
5 Most pressure is sent back down the intake runner.
6 The pressure wave arrives back at the intake valve as the intake valve opens. This effectively 'supercharges' the intake and drives air into the cylinder.
(note: the pressure wave bounces between the plenum wall and the valve more than once unless the intake runner is 10 feet long)
http://www.downingbrothers.com/super...ke-runners.htm
Document with a lot of technical information on the subject: http://nwmobilemechanicdotcom.wordpr...search-papers/
Last edited by Voith; 01-02-2014 at 08:38 AM.
01-02-2014, 10:32 AM
#178
Rainman
Rennlist Member
Rennlist Member
if all the space is coming available with brake relocation/aos delete...and custom manifolds being made...howabout dual-length runners, with rpm-actuated butterfly valves?
01-02-2014, 12:28 PM
#179
Pro
Join Date: Sep 2013
Posts: 520
Likes: 0
Received 0 Likes
on
0 Posts
Doesn't the Schlick manifolds do something like that? Or maybe it changes the size of the plenum with flaps at a certain rpm I can't remember it's been awhile I'd have to look it up
01-02-2014, 12:43 PM
#180
Rennlist Junkie Forever
This is a good example.
How many rpms do you have under the curve that are useful with a turbo engine? 3000rpms (if you're lucky...)? So even if you never drop below 4000rpms he most you'll pull is 7500rpms before the power curve rolls over. That's still not a high reving engine.
And once the engine us under boost.... the tuning of the intake has zero to do with power from a resonance stand point.
You just have to make sure that the intake runners, no matter the length, don't hurt the flow up top and that's not a difficult thing to do.
TonyG
How many rpms do you have under the curve that are useful with a turbo engine? 3000rpms (if you're lucky...)? So even if you never drop below 4000rpms he most you'll pull is 7500rpms before the power curve rolls over. That's still not a high reving engine.
And once the engine us under boost.... the tuning of the intake has zero to do with power from a resonance stand point.
You just have to make sure that the intake runners, no matter the length, don't hurt the flow up top and that's not a difficult thing to do.
TonyG
True enough but what about when you're on the track or very spirited driving and seldom below 4000rpm? Shifting the power across to the rhs will only be beneficial if we can push through the 6k ceiling. I am hopeful that between us we can find a useful compromise that proves superior than the stock intake without sacrificing any semblance of mid range whatsoever.