Cam grinder with tuned port experience?

[dhirocz]

Time has come to spec a cam. Kind of makes me nervous, it seems to me that TPI engines aren’t many peoples forte (I don’t think they were well understood even back when they were popular).

Just a few details:
427 tuned port
FIRST intake, EH ported
Dart SHP block, 4” stroke X 4.125 bore
223cc CNC ported heads, 10.25 CR
1 3/4” LT headers
Car will be running a gen 4 ECM, tuned by me with HP tuners

Want a cam that idles like stock. Intake tuned to a 3500-4000 RPM torque peak. ZL1 converter in a built 6L80E with a 3.08 rear gear. Billet step nose cam core, small base circle, LS firing order.

Yes I know it’ll make a gajillion ft lbs of torque. That’s the point and the reason for the high gear (and cruise RPM). Car will run fat rear tires and an IRS, though I’m sure that won’t help that much…

Everyone wants to cut big cams. I want an efficient and specific cam that I cannot find on the shelf. If anyone knows who has experience in this arena, I’m all ears…

 

[Grumpy]

id call crower 619.661.6477 talk with the tech guys and give then all the info and requirements
but Id point out that much displacement youll want a hydraulic roller cam in about the 215-220 in/224-230 ex range , ideally on about a 108-110 lsa but if you want the idle smooth maybe a 111-112 lsa talk to the tech guys maybe, something similar to the 00482 cam

 

[Grumpy]

BTW looks like good choices, I hope you selected a road race type 7-8 quart baffled oil pan as it helps durability and cooling
Just a few details:
427 tuned port
FIRST intake, EH ported
Dart SHP block, 4” stroke X 4.125 bore
223cc CNC ported heads, 10.25 CR
1 3/4” LT headers
Car will be running a gen 4 ECM, tuned by me with HP tuners

something in an oil pan config, similar to this that fits your block and car chassis

obviously do the required research before ordering an oil pan so it fits without issues

Summit Racing SUM-121002 Summit Racing™ Circle Track Oil Pans | Summit Racing

Free Shipping - Summit Racing™ Circle Track Oil Pans with qualifying orders of $109. Shop Oil Pans at Summit Racing.

www.summitracing.com

Summit Racing SUM-121001 Summit Racing™ Circle Track Oil Pans | Summit Racing

Free Shipping - Summit Racing™ Circle Track Oil Pans with qualifying orders of $109. Shop Oil Pans at Summit Racing.

www.summitracing.com

 

[Indycars]

Time has come to spec a cam. Kind of makes me nervous, it seems to me that TPI engines aren’t many peoples forte (I don’t think they were well understood even back when they were popular).

If you are interested I can run some Dynomation 6 simulations, but I will need more info.

Dynomation-6 Engine Simulation

Motion Software Secure Purchase

Dynomation 6 Input Variables

Bore & Stroke:
Displacement: cubic inches
Rod Length:
Heads Make/Model with flow numbers: Flow (CFM) at several lift points.
Combustion Chamber Size in CC’s:
Dome Volume: For a domed piston use a (-) negative number.
Valve Relief Volume: For a piston with valve reliefs or dish, use a (+) positive number.
Deck Clearance: (Piston to Block Surface)
Head Gasket Bore:
Head Gasket Thickness:
Valve Sizes Intake/Exhaust:
Intake Manifold Type: [Single or Dual Plane]
Manufacture/Model #:
Carburetor Size or EFI (CFM):
Header Tube Diameter: 1-5/8", 1-3/4", 1-7/8", 2.0"
Cam Part Number:
Cam Specs: Need all 8 valve timing events at seat-to-seat and at 0.050” plus lobe lift or valve lift OR post Cam Card OR give me what you have.
Rocker Ratio - Intake/Exhaust:
Cam Installed per Cam Card, or Retarded or Advanced:
Fuel Used: Gasoline (Octane ?), Methanol, Ethanol, E85 .....
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[dhirocz]

BTW looks like good choices, I hope you selected a road race type 7-8 quart baffled oil pan as it helps durability and cooling
Just a few details:
427 tuned port
FIRST intake, EH ported
Dart SHP block, 4” stroke X 4.125 bore
223cc CNC ported heads, 10.25 CR
1 3/4” LT headers
Car will be running a gen 4 ECM, tuned by me with HP tuners

something in an oil pan config, similar to this that fits your block and car chassis

obviously do the required research before ordering an oil pan so it fits without issues

Summit Racing SUM-121002 Summit Racing™ Circle Track Oil Pans | Summit Racing

Free Shipping - Summit Racing™ Circle Track Oil Pans with qualifying orders of $109. Shop Oil Pans at Summit Racing.

www.summitracing.com

Summit Racing SUM-121001 Summit Racing™ Circle Track Oil Pans | Summit Racing

Free Shipping - Summit Racing™ Circle Track Oil Pans with qualifying orders of $109. Shop Oil Pans at Summit Racing.

www.summitracing.com

Haven’t settled on a pan yet, but it will be a windage tray/rear baffle/crank scraper type of deal. That kind of torque will move the oil around in the pan in a hurry!

 

[dhirocz]

Dynomation 6 Input Variables

Bore & Stroke: 4.125 bore X 4.00 stroke
Displacement: cubic inches
Rod Length: 6.0
Heads Make/Model with flow numbers: Flow (CFM) at several lift points. See following post
Combustion Chamber Size in CC’s: 70
Valve Relief Volume: 15cc d cup dish
Deck Clearance: (Piston to Block Surface) 0
Head Gasket Bore: 4.185
Head Gasket Thickness: 0.041”
Valve Sizes Intake/Exhaust: 2.08/1.6
Intake Manifold Type: [Single or Dual Plane]
Manufacture/Model #: Tuned port @ 1.875” ID X 16.25 length
Carburetor Size or EFI (CFM): dual 58mm
Header Tube Diameter: 1-3/4"
Cam Part Number: unknown
Cam Specs: Need all 8 valve timing events at seat-to-seat and at 0.050” plus lobe lift or valve lift OR post Cam Card OR give me what you have. I’m guessing it will be in the ballpark of a 218/224/112 LSA, maybe as high as a 224/230/112, high .500’s lift with a 1.5 rocker
Rocker Ratio - Intake/Exhaust: 1.6? None yet
Cam Installed straight up
Fuel Used: E10 93 octane
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[dhirocz]

 

[dhirocz]

Please feel free to see what numbers it spits out. I’m curious, and a build like this is pretty out of the ordinary. As a matter of fact, I don’t think anything quite like this has been done before with a 6L80/coil on plug ignition/LS firing order, especially with these sort of specifications.

This is just a fun build for me, a bucket list item. The parts were somewhat hard to come by (especially the crank!) so I’m stoked it has come this far…

 

[Indycars]

I see on the FIRST website that your system could flow either 835 cfm or 1050 cfm, I assumed you are using the 1050 cfm intake, If not let me know so I can change it 835 cfm. I used the Crower 00482 cam that Grumpy suggested above, but we can try anything you want now.

There is alot of numbers that I have to be input for the first sim, so please review the PDF report for accuracy. You said to install the cam "Straight Up", to me that means a split overlap. The cam per Crower is ground with 4° Advance, which is also called "Dot-to-Dot". Just making sure we are on the same page.





Engine #1 is with the cam installed per cam card or 4° advanced and Engine #2 is retarded -4° or straight up. The DCR for engine #2 looks good for 93 octane gas.

https://garage.grumpysperformance.com/index.php?threads/dynamic-static-comp-ratio-cranking-pressure-calculator.4458/

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[Grumpy]

that cam puts the torque curve right where you stated you wanted it, and a wide peak at about 525 ft lbs
added 1.6:1 rockers and tuned headers an X pipe and dual 3" exhaust would most likely boost that a bit higher

 

[Indycars]

I did use the 1.6 rockers in the simulation along with open headers with a primary tube diameter of 1.78", I can only pick a small or larger tube diameter, but the program calculates the actual diameter used in the sim.



Below are my choices to pick from ...... and above is what Dynomation came up with.


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[dhirocz]

Sounds like it’ll have a lot of grunt. Numbers do seem a bit low once I figure in a 20% drivetrain loss... or did those numbers account for that already? I know on a 350 tuned port, I was able to run a 212/218 without any noticeable lope. On a 383, a 218/224 and it was hardly noticeable. I’m thinking something around a 224/230 or maybe a tad smaller should be doable without a noticeable idle if it’s ground with the right LSA and run at the right idle speed, but that’s just my point of view. An extra 10 degrees of so of duration should surely help the power output.

The characteristics of the tuned port intake should help keep the powerband in check, I would think.

Haven’t flowed the intake but my best guess is it’s north of 300 CFM. There should be very little loss of flow to the cylinder head, through the transition through the round runner into the rectangular port, and via frictional losses navigating the turn in the runners due to the large size and porting.

I don’t have the cam yet and I do have time to tweak this a bit if there are more gains to be had making minor changes. I don’t mind as long as the ‘tuned port’ powerband isn’t messed with much.

To be honest, I have considered using a superram ‘pizza box’ plenum I have on the shelf, halving a set of runners and making a super ram style of intake based on the FIRST. That’s should push the torque peak up to about 4500 and the HP peak as well, and buy me the ability to run a little more cam, but would require enlarging the rest of the runner ID’s to 1.9” to maximize flow with the new powerband.

 

[Indycars]

Sounds like it’ll have a lot of grunt. Numbers do seem a bit low once I figure in a 20% drivetrain loss... or did those numbers account for that already?

No drive train loss and open headers .... numbers are at the flywheel.

I don’t have the cam yet and I do have time to tweak this a bit if there are more gains to be had making minor changes.

We can run as many sims as you like, 90% of the work is in the first simulation, after that all I have to do is change the cam.

Dynomation has what's called an Iterator that runs 1000's of camshafts, among other options, saving the best 10 sims I can specify Peak HP/TQ or (Area Under The Curve) HP or TQ.

What do you want to do next ??? Did you look over the PDF file and verify it's accuracy ???




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[Grumpy]

yes you can boost peak power if you swap to a more radical cam, like the one used in RICKS CAR the crower 00471,

but you lose some driveability, like the smooth idle and the just off idle torque you stated you wanted.
this is far less critical, in a 2100 lb T-bucket ,keep in mind that's a judgement call all of us see DRIVEABILITY a bit differently
in a 2100 lb T-bucket driveability will be different than in a corvette that weights 1000-1200 lbs more.
Id strongly suggest you concentrate on maximizing the peak torque curve in the 4000rpm-5500 rpm range to maximize the FIRST INTAKE ,the nice heads and that LARGER DISPLACEMENT SBC, POWER BAND. this should realistically result in a car that can devastate the tires at will.

 

[Indycars]

I did some looking at cams that I already have specs on and came up with the Crower 00468. This increases the overlap from 40.5° to 61.5°. I again used the 1.6 RR, increasing the lift from .535/.550 to .571/.587 . HP increased from 501 to 527 at 5600 RPM. DCR still looks good at 8.28 for 93 octane.





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[Grumpy]

its doing the tweaks and software testing like that that gets you closer to ideal without having to spend a ton of cash on parts and testing.

 

[dhirocz]

The info in that pdf looks good to me, except for one thing. I don’t know if it matters but it does have it shown as an LS7 though.

Can that sim account for the airflow dynamics and the tuning effect of a tuned port?

I do want to keep the drivability intact. However, I don’t want to leave anything on the table either. I guess what I’m interested in knowing is what changes that different cams that can potentially deliver that drivability would have on the powerband, as well as how much of that influence is the cam and how much is the intake itself. Hopefully that makes sense.

a couple thoughts:

-I am planning on running a higher rocker ratio to increase dwell time in higher lift areas to take advantage of the head flow without running excessively aggressive lobes. I’m open to a 1.7 or even higher ratio.

-I do not have headers yet, and while I didn’t think a ‘tame’ engine like this running less aggressive hardware would need more than a 1-3/4” header into a 3” exhaust I’m open to a 1-7/8” header.

-I am planning on a modified plenum to run a dual 58mm throttle body, which I have. I am also open to a mono blade if the extra cfm through the throttle body would be beneficial.

-I do tend to install my cams dot to dot, and would assume any benefit to changing this with a custom grind would be ‘ground in’. However, I’m open to changing this as well if there is any benefit.

-I have contemplated using crankcase evac on this engine. I used the original pcv location on an LT1 as a central location to hook up crankcase evac years ago and it actually worked very well when I ran it through a catch can.

 

[Grumpy]

don't bother running a larger throttle body than a single dual 58 mm throttle body,
or at max a 1000 cfm mono blade,
it won,t help, lots of testing proves minimal results at best,
and don't bother running a higher rocker ratio than 1.6:1,
the valve train harmonics and control issues go to hell far faster,over 5500 rpm and above as rpms increase than any minimal potential benefit might result.
as to larger primary tube headers, the benefit at the 4000rpm-5500rpm power band don't show much benefit or problem with either choice as its the cam LSA & valve diameter/curtain area ratio to displacement, more that the primary tube cross section that matters here.

calculating overlap and lsa, or lca etc.

First Id point out that nearly everyone occasionally confuses or at least makes the mistake of using the wrong abbreviation, (LSA, and LCA) these are terms, that are almost, at least in many discussions ,incorrectly used interchangeably which they are not. which they are not. Quote Reply...

garage.grumpysperformance.com

 

[Indycars]

The info in that pdf looks good to me, except for one thing. I don’t know if it matters but it does have it shown as an LS7 though.

That's just a label, it will not effect the numbers. Thanks for taking the time to verify, sometimes alot of comparisons relate back to the first sim and if it's invalid, then you can see this would muddy the waters.

Can that sim account for the airflow dynamics and the tuning effect of a tuned port?

Yes, Dynomation can do what it calls "Wave Action" (WA). So far I have used the simpler method called "Fill & Empty". Most people are not willing to take all the measurements required for WA. It will require that you have the heads and intake manifold off the engine to take the required measurements. If this sounds like something you want to pursue further, then I would recommend you download the Dynomation Manual.. It will be a fairly lengthy read. Once you get toward the bottom of the manual, it's get more into the theory. Say maybe after page 100.

Below are the parameter for using WA



Depending on your header configurations you could need only few dimensions to almost all those shown below.



If you really get into this WA side of the exhaust, I also have PipeMax for modeling the exhaust system.

PipeMax Professional Engine and Header Design

I grabbed a few paragraphs from the Dynomation manual, this should give you a feel for what Dynomation does with WA.

The Wave-Action model picks up where the Filling-And-Emptying method
leaves off and “homes in” on the best port sizes and shapes, runner lengths, header
configuration and tubing dimensions, cam timing and valve motion, and other engine
parameters, providing unprecedented accuracy for the serious engine designer and
builder.

Which Simulation Model?
Generally, if you need to quickly determine how an engine will respond to cam
timing changes, specific intake manifolds, open-headers vs. mufflers, or you don't
have access to all the required intake and exhaust port dimensions for the WA
model, the Filling-And-Emptying simulation provides a quick and remarkably ac-
curate way to build up and test an engine. However, if you are “digging into” the
details of mass flow, port shapes and lengths, and exhaust tubing dimensions, the
Wave-Action model will analyze the several additional inputs required to complete
this more complex simulation.

FE vs WA Note: The Filling-And-Emptying model calculates optimum port
dimensions before the simulation process begins. As a result, in some cases,
it may predict higher power than the WA model because it starts off with
optimum dimensions (these values are displayed in the Simulation Log in
Dynomation when running the FE model). By carefully tuning runner lengths
and exhaust tubing dimensions in the WA simulation, results should match
reasonably closely with the FE, especially when engine design is more-or-less
“standard.” However, if you are modeling exotic engine designs, you should
use the Wave-Action model whenever possible.
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[Indycars]

I do want to keep the drivability intact. However, I don’t want to leave anything on the table either. I guess what I’m interested in knowing is what changes that different cams that can potentially deliver that drivability would have on the powerband, as well as how much of that influence is the cam and how much is the intake itself. Hopefully that makes sense.

It kinda makes sense. I think you would need the dyno curves for your present engine and then compare that to the dyno curves for any potential engine. That might give you a grasp on what the changes might mean to you. As far as camshaft or intake manifold making the difference ...... as you know it's a system, neither one operates in isolation. Changing the weakest link is going to have the greatest effect.

-I am planning on running a higher rocker ratio to increase dwell time in higher lift areas to take advantage of the head flow without running excessively aggressive lobes. I’m open to a 1.7 or even higher ratio.

I can model those changes. But as Grumpy has noted, going above 1.6 RR creates more problems. One he didn't mention is the need to run offset lifters and may require grinding more clearance thru the head for the pushrod. Even at 1.6 RR you will want to check these clearances.

I do not have headers yet, and while I didn’t think a ‘tame’ engine like this running less aggressive hardware would need more than a 1-3/4” header into a 3” exhaust I’m open to a 1-7/8” header.

PipeMax would provide the best answer, but again it's considerably more time on your part. You can get custom headers built and you do the design mockup. Then send it out for them to create. They will send you kit for the mockup and when you send it back for them to build they apply the cost of the kit to your headers.

Header Design Using Dynomation 6 & PipeMax 4.7

At this point I'm making some wild ass guesses, just so I can get some numbers. Dynomation cannot provide a graph until it has enough information, so that's why I'm making some WAG's. Just want to get some numbers, then when I pull the top of the motor apart this winter, I can measure and get...

garage.grumpysperformance.com

-I do tend to install my cams dot to dot, and would assume any benefit to changing this with a custom grind would be ‘ground in’. However, I’m open to changing this as well if there is any benefit.

You could have a custom grind done, but you would get the exact same results by retarding the cam with anyone of many different ways. Most often done with a crank gear. Just use the appropriate keyway.


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