Cam selection help with new heads

94gtsn95

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Hi all. Me and a buddy are working on a project car together and I'd like to pick your guys' brains.

Car is a 94 mustang gt, T5, with cia and 3.73's. Ran a best of 14.3 in the quarter before we started the tear down.

Already picked up some used pieces as this is a budget build. Trickflow Street Heat intake (upper and lower), high flow elbow, 75mm throttle body, and an SCT chip with Bama tune (got this new and they will update a tune for it once the build is done).

We were looking for good deals on used heads before we picked up a cam. Came across a set of Holly Systemax Aluminum Heads for a great price.

Specs on Heads:
Holly Systemax Heads, Casting #12113B, 34R, #12156, holly part number part #300-574
2.02 / 1.60 Valves
170cc Intake
71cc Exhaust
63cc Combustion Chambers
Pedestal Mount Rocker Mounts
Race Ported

Bought them from an old guy that said they had been "Race Ported" by an old school Circle track legend (don't recall the name) but didn't have any additional information of the port work. They came with new springs and Comp 1.6 Roller Rockers and only have about 500miles on everything.

So now were looking for a cam. The car is a daily driver but want to maximize 1/4 times for this set up. Dyno #'s don't matter, just want a cam that will pull hard into the upper RPM, and maximizes this head setup, without loosing a ton of bottom end (but understand some will be lost). Goal would be to get it down to low 13's and also be able to roll race here or there but it's primarily a dig car.


Would also like to not have to flycut the pistons if at all possible to save money on buying the fly cutting tools.

Looking at the TFS Stage 2 cam or the XE-274HR. The cam we are willing to buy new as they are only about $70 more than the alphabet cams.

Are these good cam's for the setup? Would they require fly cutting? I know the heads are a little big so is there a specific cam that would work better for the increased valve size and runner volume?

We will be measuring for PTV and measuring for Push Rod length once everything gets put together. And we'll need to go to a 24# injector correct? It's got a brand new stock fuel pump, will that work or does it HAVE to be upgraded? Will also be putting a new timing chain, oil pump, head gaskets ect. to complete the build.

Any advice is appreciated, Thank you for your help!!
 
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94gtsn95

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This will be the only way to know for sure. Otherwise, contact Ed Curtis at FTI for a custom cam.


Already did that. He's big on the other forum i'm on for my gto. He's just a little too busy to just chat about the cam. He can quote us a custom cam but again being a super budget build were trying to save as much money as possible. An ots cam would probably be best. Just wondering if anyone has experience with these heads or has a similar setup.
 

96blak54

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Valve ratio is 79.2% which leads me to think rpms wont be a problem. Big cam like Comp cams 274 is going to cause valve float regardless. Not a bad thing but be prepared for it like good push rods and proper valve springs.

Most guys use a middle stage street friendly grind for the low rpm torque and utilize high rpm valve float for the longer duration needed in the rpm's. Valves are going to float regarless. Gotta figure out valve spring weight for it through loads of track passes. This route is about budget friendly as it gets. Lots of track passes and wrenching to find the sweet spot. And since its a push rod engine, you can utilize 3 rocker ratios and choose the ratio for either valve.

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94gtsn95

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Valve ratio is 79.2% which leads me to think rpms wont be a problem. Big cam like Comp cams 274 is going to cause valve float regardless. Not a bad thing but be prepared for it like good push rods and proper valve springs.

Most guys use a middle stage street friendly grind for the low rpm torque and utilize high rpm valve float for the longer duration needed in the rpm's. Valves are going to float regarless. Gotta figure out valve spring weight for it through loads of track passes. This route is about budget friendly as it gets. Lots of track passes and wrenching to find the sweet spot. And since its a push rod engine, you can utilize 3 rocker ratios and choose the ratio for either valve.

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Why would the valves float? They've got brand new springs good to .600 lift. They also came with new comp 1.6 roller rockers and we'll be sticking with those. Will also be putting in ford racing lifters. I can't see why valve float would be an issue.
 

96blak54

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All valves float to some degree. Valve spring reverberation, weight of all the mechanism, even valve bounce from spring reverberation. In a perfect world, the valve train would track a cam profile perfectly at all rpm. Its just not so. Especially in the block cams

Lets see if I can explain. Valve float can be very usefull. A mild cam thats great for street torque can have a profile that will fly the valve open fast causing it to hang breifly at high rpm...hence longer duration. Since we all have roller cams, valve bounce when slammed shut is nearly eliminated cause the lobes are big and give the lifter a smooth landing.

Lets recap. Torque low street bottom end, veriable valve duration at upper rpm. Can you see what I mean?

If it were me, id step down to a comp 262something, use said rockers, use heavier exhaust spring, start with lighter intake spring, not a stock one. Good aftermarket.

Dont get me wrong here, im not saying your idea of parts selection is bad. Im simply offering proven ideas building your project and achieving the results you desire. You asked for ideas. Figure id help a brother out!

I will say a comp 274cam is 13+ static compression to maximize the cams potential, but youll have to be on your game fuel atomization wise.



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94gtsn95

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That's why I'm here, to get good recommendations on a cam for this setup. I'm a chevy and pontiac guy, I don't know what works best with these little 302's. although I do know what valve float is ;)

One of the reasons we picked up these heads is because they came with new springs, all the valve train parts, and new roller rockers. This saved us from having to buy everything individually. We don't want to spend extra money on changing the springs if not absolutely necessary. So keep that in mind for cam recommendations.

As far as the 274hr, that was just a cam I saw people using when doing research on h/c/i setups. I see a lot of TFS Stage 2's as well. I'm open to any cam that's going to maximize the power from those heads. If it means smaller that's fine. Actually that's probably better as we would love to avoid fly cutting the pistons. And were not those "it has to have a bitchin idle man..." type of people We could care less if it thumps or purs like a kitten. Goal is low 13's with the setup so what ever is going to maximize the 1/4 mile potential is fine by us!
 
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94gtsn95

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Anyone running the Comp Magnum line of cams? On EdC's website he has a couple Magnum cams listed.

The Magnum 281HR has less lift but still decent duration.
Specs are:
220/224
512/533
112+4
2000-5500rpm range

Would this be better for the heads listed above?
 

95opal

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Those are the old school holley heads that were actually cast by AFR. With that street heat intake I wouldn't worry about upper rpm power as that thing is gonna kill any chance of making power. If possible swap it out for a track heat upper. May also want to consider milling those heads a tad bit. your leaning towards a very mild build with your parts selection. great for a street set up but will do nothing for you at the track,
 
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94gtsn95

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Those are the old school holley heads that were actually cast by AFR. With that street heat intake I wouldn't worry about upper rpm power as that thing is gonna kill any chance of making power. If possible swap it out for a track heat upper. May also want to consider milling those heads a tad bit. your leaning towards a very mild build with your parts selection. great for a street set up but will do nothing for you at the track,

I heard milling these heads is not good for the valve train geometry and can increase valve guide wear because of the 17degree valves.

And are you saying with the mods listed above and these race ported 170cc heads aren't going to get us down to mid - low 13's? lol ok. I guess all the people that run similar set ups that are down in the 12's can't do it either...
 

95opal

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I heard milling these heads is not good for the valve train geometry and can increase valve guide wear because of the 17degree valves.

And are you saying with the mods listed above and these race ported 170cc heads aren't going to get us down to mid - low 13's? lol ok. I guess all the people that run similar set ups that are down in the 12's can't do it either...

Nothing wrong with those heads. Ive personally seen a set put down 340 on a 302. You intake is going to chocke any capabilities of those heads. Go back and read what i stated instead of throwing your shit i n my mouth. Now as for further help or advice just use the shit that comes out of your mouth. Have a wonderful day dipshit.
 
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94gtsn95

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Nothing wrong with those heads. Ive personally seen a set put down 340 on a 302. You intake is going to chocke any capabilities of those heads. Go back and read what i stated instead of throwing your shit i n my mouth. Now as for further help or advice just use the shit that comes out of your mouth. Have a wonderful day dipshit.

I'll take my shit over your shit any day. I've been working on cars and building hot rods since you were shitting in your diapers. I realized I can't rely on this forum and have already talked to the pro's at a few engine shops. Have a wonderful day jerk off.
 

lwarrior1016

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I'll take my shit over your shit any day. I've been working on cars and building hot rods since you were shitting in your diapers. I realized I can't rely on this forum and have already talked to the pro's at a few engine shops. Have a wonderful day jerk off.

Do you even know who [MENTION=9659]95opal[/MENTION] is?

Im absolutely positive that you havent seen his work and have no idea of his age or knowledge.
 

96blak54

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95opal used degrade words first. You guys apologize and move on

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evilcw311

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Wait, let me get this straight.......

New guy ask for help, [MENTION=9659]95opal[/MENTION] gives help, new guy disregards 95opal's help with a smirk, 95opal then responds on his own defense.......... & 95opal is suppose to apologize?!?!

New guy, maybe you should slow down and learn who has proper knowledge and who doesn't. 95opal isn't a kid for one, I think he's old enough to be my grandfather but not sure. Lol

95opal is one of a handful who's knowledge and know how is not to be questioned. Do a little research before you spat off. Maybe, just maybe you will learn something. There's a few others here who's knowledge is priceless but won't take well to being mocked.

I've been building street rods and muscle cars for several years myself and no matter how much I think I know I always take the time to listen as there's more to learn from others.

With that being said, learn on!!!


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95opal

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I'll take my shit over your shit any day. I've been working on cars and building hot rods since you were shitting in your diapers. I realized I can't rely on this forum and have already talked to the pro's at a few engine shops. Have a wonderful day jerk off.

Lmao better check yourself at the door little man. About the time you were getting out of diapers and into your underoos I was tearing apart my first foxbody....an 85gt.
By the time you were old enough to drive I had built more mustangs than you had birthdays. Now if youve already discussed this with your pro builders then there is no need to post asking us young guys for input. When you finally grow up an get to my age in another 20 years youll get tired of the smart ass know it alls to. Until then you might want to soak up some of that knowledege that yoir missing. Good luck with the build
 
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94gtsn95

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I kinda figured this would happen. Most forums aren't exactly nice to new comers no matter how much knowledge the person may have... I'm not opposed to learning new things, hence why I took the time to create an account and post on this forum.

But how are blanket statements like "this will never work at the track" helpful??

I was looking for... "Well with this setup, the intake and those heads, a XXX cam would probably work best because of XXX reasons" or "Stay away from XXX cam because of XXX reasons" or "with those valves and that runner size go with a cam with xxx duration and xxx overlap because it will help xxx"

And like the statement "That intake is going to kill any power"... again is just a blanket statement. This is a budget build and that TFS intake, upper and lower, was acquired used for $150 in beautiful condition. The point of me posting wasn't so everyone can recommend that absolute best parts. It's like yeah, if we had a huge budget we'd just buy all the best parts that compliment what we have and call it a day. But that's not the case and that was stated. This Intake may rob a few ponies up top or limit the upper end RPM band to a certain extent but again this is what we have to work with and by no means will this be worse than the stock intake. (And by no means will it not work at the track.) And that's when I would expect a "Well since it's a street heat intake, you may wan't to focus on a XXX type of cam that will give you XXX to compliment it". Not just start dogging that parts we have and say it won't work. And as stated very clearly in the opening post, we're just looking to have a low 13 sec car. If I said we're looking to have a low 12 sec car, I would expect those type of answers.

Opal I'm no doubting you have knowledge, i was fast to jump just as you were fast to call me Jerk Off. With that amount of knowledge you have it would have been nice for you to actually give some recommendations. I can't "Soak up knowledge" when hardly any is being thrown out for what I was asking in the first place, but I digress.

I've talked to a local mustang speed shop and I have spec'd out what we're going to do. I'll be back and let everyone know how bad these budget parts do on the track...
 

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