300 Turbo Cam

curts56

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I’m getting close to bringing my 300 to the machine shop and would like to get a cam on order that would work with my goal of around 300+ HP with a max RPM of 4000. Here are the pieces I have so far:

Holley EFI Super Sniper 650
Offenhauser C Intake
Turbosmart Race Port Blow-Off Valve
Garrett TO4B30 Turbocharger (came from my old Ak Miller setup)
Compressor: 0.60 A/R 55mm Inducer/70mm Exducer
Turbine: 0.81 A/R P-Trim (measures at about 65mm)
Turbonetics 35mm Wastegate
Forged Crank
ARP Head and Main Studs
Pistons: TBD
Rods: TBD
Cam: TBD

The head will get screw in studs, 1.94 intake and 1.60 exhaust valves along with some porting to blend the bowls. I plugged some numbers into Matchbot with a turbo that I believe is close to what I have:

http://www.turbos.borgwarner.com/go/AJPS56

The turbo and wastegate are mounted on a J-bend/HD manifold. At the moment I’m leaning towards water/methanol injection, mostly because I don’t know if I’ll have room for an intercooler in the nose of my 56 F-100 after installing an A/C condenser.

I currently have an Iskendarian 331MK “Mile-A-More” cam kit (comes with lifters, springs, push rods) but would like a cam that’s designed for a turbo. I thought about getting Isky’s turbo cam, but I’ve seen some posts that say it’s not the best choice.

Any suggestions on what cam parameters would be best for my application? Since the other parts are Isky should I have Isky grind a custom cam?
 

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Hey, looks good. Re. the Isky cam...

The Mile-A-Mor was, of course, Ak Miller's personal favorite cam for a carburated Turbo 300 street motor. Ak told me that his dyno testing showed that the Mile-A-Mor dropped the torque peak to 1,650rpm (from an actual factory peak of 1,800rpm), torque would stay fairly flat to about 3400-3600rpm, and that it was really useless to rev it over 4,000rpm, ie. upshift to the next gear! That was '70s-'80s technology, and definitely for street/daily driver/occasional tow-haul usage vs. dragstrip/race only advice.

Isky later came out with their "TurboCycle-A-Cam" cam, supposedly aimed at 1,000-5,000rpm range, with split I/E duration & lift. https://iskycams.com/shop/ymm.php?cat=1 ... model=Base Looks like Isky is recommending fairly low compression for the Mile-A-Mor (no mention of using it with a turbo), but also talking a maximum 7 PSI pressurization with their TurboCycle-A-Cam.

Ak said to keep the static c.r. around 8-8.5 to 1 with the Mile-A-Mor & his turbo setup for the Ford 300", limiting boost to 8 or 9psi, as well as using boost-referenced water/meth cooling of the intake charge. Again... "old days", no intercooler recommended with carbed intake, over concerns about "icing up", and his kit was for a Ford 2bbl. IIRC Ak's dyno runs had shown around 300hp at the flywheel, with his Ford 300" kit & the Mile-A-Mor cam; staying under 4,000rpm, that says a lot about the torque increase provided.

Unlike many 'turbocharger kit' sellers in those days, Ak had done the actual dyno development work to back up his sales offerings, many aimed at bolting onto factory stock engines for street & commercial use. He threw out some rough estimates for increases on otherwise factory stock motors with his street turbo kits of about 40% increase in HP, but 70% increase in torque, staying with the same RPM ranges as stock.

Sorry I don't have any cold, hard numbers or personal dyno slips to post, but that's my recollections on Ak's kit & the Isky cam kit you have. I bought Ak's kit & also picked up the Mile-A-Mor kit from Isky. My 307" Ford 6 & drivetrain mechanicals are all built, safely covered & the entire project has been "in mothballs" in my shop, relegated to lower priority, in favor of raising a second family, wild soccer schedules, grad. classes & vocational 'side trips' (for more years than I want to think about). Hopefully I can get back to it next year & get it on the road... and in the dirt!

Keep going with your build.I'll be interested to see it come together & roll!


J.R.
SoCal
 
This is the Crower version of the Isky turbo cam.
It adds a little more exhaust duration to raise the rpm limit but is still a split duration to work well with a log exhaust manifold.
Install the cam 4 degrees advanced with the intake lobe center at 110* ATDC.
Keep the static compression ratio below 8.5

[image]https://www.dropbox.com/s/1wf6po69uvsfzg0/Crower%20Cam3.jpg?raw=1[/image]
 
331TA (turbocycle A) .445”/.415” 208/194 262/250 114deg
The isky cam specs for reference.

Not alot of duration at .050, i found a crower posted once on here that looked to have a little more duration and a little more lift on the exhaust side. Seems a reverse pattern and 112 or 114 lobe seperation makes these cams turbo specific. Im going to try a comp 268h but i dont believe its the right direction for the best turbo performance.

Screenshot_20190619-184535.png
 
Phase3":1fxczlv1 said:
Im going to try a comp 268h but i dont believe its the right direction for the best turbo performance.

A larger cam works if you are looking at a higher rpm power band to make more HP.
The single pattern cam is OK if you are not using a log type exhaust manifold.
You really want a wider LSA than the Comp 268 110*
The Comp 268 has been tried before with a turbo using the stock log exhaust manifold. The power drops off early and quickly.
 
J.R, thanks for all the Ak Miller history. I was going to use the Ak 300 setup I have, but decided a blow through system would be a better choice for a number of reasons.

Thanks Paul for the cam specs. Since I have Isky lifters would it be better to have Isky grind a cam or will they be ok with the Crower cam?

Maybe I should ask these questions on the 240-300 forum, but I'll start here. I'm using ARP main studs. What should I do to support the oil pickup? Someone mentioned getting a longer stud, but I don't see individual studs listed in the ARP catalog. Also, would making a spacer out of 1/4" aluminum plate be ok for spacing the oil pump away from the main stud?
 
Allensfasteners.com sells individual arp studs...One thing you could do if you have a sufficient amount of threads past the stud nut when tight is to tig a bolt to a nut and tighten down tight to the stud nut with loc tight.
Nothing wrong with a spacer, it was standard procedure when lowering the sump...but you have to maintain the alignment and lengthen the drive....See big six forum 2nd page ''Tractor puller for some ideas...That is todays project,3'' spacer with machined male and female alignment guides, may have to shorten if not stable enough. Who am I kidding probably this mouths project. :cry:
PS your engine looks very nice (y)
 
curts56":1kecelq2 said:
would making a spacer out of 1/4" aluminum plate be ok for spacing the oil pump away from the main stud?
Yes.
You will need to get a longer oil pump hex drive from a Ford V8 and cut it to the proper length.
Then you will need to modify the oil pump pickup so the pickup to oil pan spacing is correct.

If you can change to a center hump oil pan then you can use the short pickup that doesn't use a support bracket.

Side Note:
On your Matchbot Inputs, Even with a big valve ported head, the Volumetric Efficiency drops off after 3500 rpm with a cam profile for this application.
 
drag-200stang":4pbaprtz said:
Allensfasteners.com sells individual arp studs...
Thanks. I'll check them out.

pmuller9":4pbaprtz said:
Yes.
You will need to get a longer oil pump hex drive from a Ford V8 and cut it to the proper length.
Then you will need to modify the oil pump pickup so the pickup to oil pan spacing is correct.

How close should the pickup be from the bottom of the pan? I have a rear sump pan since the center sump won't clear the cross member.
 
curts56":1l1ulyiq said:
How close should the pickup be from the bottom of the pan? I have a rear sump pan since the center sump won't clear the cross member.
Around 3/8"
 
pmuller9":1vehwni1 said:
curts56":1vehwni1 said:
How close should the pickup be from the bottom of the pan? I have a rear sump pan since the center sump won't clear the cross member.
Around 3/8"
Thanks.
 
pmuller9":85d7v1s1 said:
Phase3":85d7v1s1 said:
Im going to try a comp 268h but i dont believe its the right direction for the best turbo performance.

A larger cam works if you are looking at a higher rpm power band to make more HP.
The single pattern cam is OK if you are not using a log type exhaust manifold.
You really want a wider LSA than the Comp 268 110*
The Comp 268 has been tried before with a turbo using the stock log exhaust manifold. The power drops off early and quickly.
How about with EFI manifolds?
 
guhfluh":1wo8f1ih said:
How about with EFI manifolds?
Much better than the log style manifold especially if the turbo has a twin scroll turbine housing and you keep the front and rear exhaust separate to each side of the turbine housing.
Then a single pattern cam would be alright to use. Just keep the LSA wide with a 112 minimum and more as the cam duration increases for higher rpm/horsepower applications.
 
Ak Miller used the 300 Heavy Duty exhaust manafolds in his Turbo kits with larger outlet (2 1/2 inch I think) that the Bigger trucks like F500 Up. These would surely out flow the standard pickup log exhaust manifold used on F100 to F350's and maybe even be a close match to the EFI manafolds. :nod: (y)
 
bubba22349":st7kt0tj said:
Ak Miller used the 300 Heavy Duty exhaust manafolds in his Turbo kits with larger outlet (2 1/2 inch I think) that the Bigger trucks like F500 Up. These would surely out flow the standard pickup log exhaust manifold used on F100 to F350's and maybe even be a close match to the EFI manafolds. :nod: (y)
Flow is not the problem.
It has to do with exhaust pulse isolation between cylinders.

On a street turbo setup where turbine housing A/R are less than one, log style exhaust manifold pressure can be over twice what the intake manifold boost pressure is.
 
it's beautiful work on the assembly of the engine.
tell us about the Jay pipe, specifically how u attached to the manifold,
and how u support the weight of the turbo
 
The flange is made out of 3/8" plate and mates directly with the flat surface of the exhaust manifold outlet. Hopefully that will be more reliable than a donut gasket. I made a template out of hardboard panel then cut out the flange using a plasma cutter.

The flange was welded to one end of a 2-1/2", 3" radius J-bend and the turbo flange was welded to the other. The 1-1/2" tubing is for the wastegate.

The HD manifold is very beefy so it shouldn't have a problem supporting the turbo.

[image]http://www.ckdesign-inc.com/images/Exhaust/ExhaustFlange3.JPG[/image]
[image]http://www.ckdesign-inc.com/images/Exhaust/ExhaustFlange4.JPG[/image]
[image]http://www.ckdesign-inc.com/images/Exhaust/ExhaustFlange5.JPG[/image]
[image]http://www.ckdesign-inc.com/images/Exhaust/ExhaustFlange6.JPG[/image]
 
yes, very pretty.
impressive.
I did similar, or had it done by a hand steadier than mine.
though I was in on the process.
a 2.5 pipe with a bead circumference-ing the j pipe, about 1.5 inches from the pipe's end,
my flange , available online , stainless, 1/2 inch holds the j pipe to the inside ledge of the manifold, by tightening the three bolts squeezing the bead between the manifold and flange.
I do not know if this will work, it should. but my concern is the weight will literally drag the manifold off the face of the head by simple dead weight.
the HD manifold provides for the pipe to be inserted into the manifold 1.5 inches or so.
having the flanges "face-mated", may expose u to leaks or warpath due to dissimilar metals reacting to extreme heat.

I install my manifolds with the engine laying flat on the engine stand, so I can eyeball the centering of the two manifolds.
I'm going to try:
use studs, bush the studs at their base, so the int/exh, manifolds are precisely centered around the stud.
then fab up the metal clips that will support the weight, because they reach down from the stud, and wrap around the bottom of the exhaust flange.
somewhere on here someone built these clips to nice effect.


on factory trucks the down pipe helped support the manifold assy. because it was essentially verticsl, and we'll anchored below.
I'm not so sure the exhaust pipe with a turbo, will as readily lend such support. I worry about failure in some remote location.
 
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