Fox Trick Flow 170’s on a 331 Stroker

Sure, it's not a secret recipe.

347ci Ford Competition Small Block

New Trickflow 170cc runner CNC chamber heads Track heat


q 61cc Chamber
q 2.02 In valves
q 1.600 Ex valves
q CNC Chamber
q 1.6 Roller rockers
q 10 degree keepers
q 1.440 dual valve springs
q 7/16 studs

347 Ford Engine Block

q A Ford Roller Block Was Used
q Block was square decked
q Block was line honed
q Block was square bored and honed with honing plates
q Engine was trial assembled twice
q Lifter bores are honed

Competition 347ci Ford Parts List Break Down

q TFS Wiseco Forged .030 pistons
q .030 Filt Fit Moly Rings
q A 5140 Steel 28oz 3.400 stroke
q Engine is 28oz balanced
q A Set of Scat SIR floated rods 5.400 length
q Large radius Main and rod bearings
q Seal Power cam bearings
q Brass Freeze Plugs
q Cam plate and bolts
q Mell oil pump and drive
q Canton pick up
q New ARP head bolts
q A complete gasket set
q Oil and Filter
q Double Roller timing set
q A Anderson N41 cam
q A set of Chrome moly Push rods
q A New Aluminum Timing Cover
q 1.6 Roller Rockers TFS
q A Trickflow Intake 51511002

In addition,

Accufab 75mmTbody
Pro-M mass air for 39# injectors
FMS 39# injectors
what Intake?
 
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I don't think anyone is wrong in thinking a particular way, because it's a hobby and it's different strokes for different folks. However, you can get more torque at the wheel through gearing. You can never get more power through gearing.

Which two sets of heads are you asking about? E7s to TFS 170s? If so, those TFS heads are going to beat the E7s like a red-headed step-child in hp and tq everywhere in the power band.
The E7 heads are not even worth discussing and I understand torque and gearing, that's why I run the 355s with my current setup. It's pretty spirited to drive.
 
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what would be your suggestion for him in a nutshell? Maybe I'll be doing the same thing come one day, similiar situation. Right now I'll put the motor from my sig with 190 k in the 94 cobra. I'll change the exhaust and few other things while I'm messing with it and see how I like the car overall. If I think I need more out of it I'll need to decide rather I just want to do a 306 or 331. I will be using the same components with likely changing the cam if I do a 331. I'll also be more than likely when i finish the swap doing a 351 for the other car so that's why with the 94 cobra just throwing in the engine from the wrecked car makes sense.

I say if you want a $5k engine, do the 306 with TF 170cc heads. If you want a $10k engine, do the 347 with 11R 205 heads. It's all about budget.

Kurt
 
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Those heads flow plenty for a 331 or a 347. Everybody forgets the old days when you couldn't buy a good set of aftermarket heads. Hell a buddy back in the day ran 11's in a 3800 lb Chevelle with a half ass home ported set of 441's. Another guy I knew hit 9.80's in a Falcon with ported iron heads (289 shifted @ (gasp) 8800 rpm). You don't need a high port on a mid 300 CID motor. And if your building a stroker with the factory roller block, your going to want to keep the rpms down. I don't care if "500" rwhp is considered safe. That's bulls###. I wouldn't run anymore than 325-350 and turn 5500-5800 rpm. I've seen plenty break at less than that. I just don't see dropping $1500 on a rotating assembly, same on heads to have it grenade. I bought a Systemaxx intake from a guy that was running 10# on one with an S-trim. He'd broken 2 blocks. I sold it to a guy who'd just broken his 347 with a Systemaxx kit, right at 340 rwhp. He was moving everything to an R block.
 
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Those heads flow plenty for a 331 or a 347. Everybody forgets the old days when you couldn't buy a good set of aftermarket heads. Hell a buddy back in the day ran 11's in a 3800 lb Chevelle with a half ass home ported set of 441's. Another guy I knew hit 9.80's in a Falcon with ported iron heads (289 shifted @ (gasp) 8800 rpm). You don't need a high port on a mid 300 CID motor. And if your building a stroker with the factory roller block, your going to want to keep the rpms down. I don't care if "500" rwhp is considered safe. That's bulls###. I wouldn't run anymore than 325-350 and turn 5500-5800 rpm. I've seen plenty break at less than that. I just don't see dropping $1500 on a rotating assembly, same on heads to have it grenade. I bought a Systemaxx intake from a guy that was running 10# on one with an S-trim. He'd broken 2 blocks. I sold it to a guy who'd just broken his 347 with a Systemaxx kit, right at 340 rwhp. He was moving everything to an R block.

Times are changing. I don't only remember the good old days, I am the old days. I'm still running Canfield 192cc heads, because that's the biggest "street" head you could get. Someone on here is spinning a stock block to 8000rpms, which one of you was that? As for me, stock block has worked fine so far.

Kurt
 
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I say if you want a $5k engine, do the 306 with TF 170cc heads. If you want a $10k engine, do the 347 with 11R 205 heads. It's all about budget.

Kurt
all things being the same, the difference from 306 to 347 as far as hp/tq might be what around 30-50 hp'ish?
 
all things being the same, the difference from 306 to 347 as far as hp/tq might be what around 30-50 hp'ish?
I don't think it's that simple. If you're taking a 306 thats is putting 300 +/- rwhp and just put a 347 stroker kit in it and change nothing else, then you're in the +/-50 additional hp range. But most, if not everyone, who is bothering to tear their motor apart to do that would leave everything else as it was. Wether it's heads/cam, fuel, tuning, etc.
 
all things being the same, the difference from 306 to 347 as far as hp/tq might be what around 30-50 hp'ish?

No, if both engines are set up ideal (i.e. the same compression ratio, and ideal camshaft), the difference between the two engines is 0 hp. The difference is how fast the engine has to turn before it starts sucking in more air than the heads can flow. The power produced is a direct relation to the amount of air and fuel coming in. So, let's say that a set of TF 170cc heads have the flow potential to make 350hp. The 302 is going to make that 350hp at 5500rpms, and the 347 is going to make that 350hp at 5000rpms. Those aren't exact numbers, but pretty close.

If you are talking about full out acceleration, like drag racing, it doesn't matter much, because clutch release is going to be like 6000 rpms, and from there on out, you keep it right in the powerband. On the street, the stroker engine is going to be a little more fun, because it's going to get into the powerband from low RPMs faster, theoretically. In an old Mustang on street tires, you are pretty much over the tire limit instantly anyway, so you wouldn't notice. On that size head though, it might not even be noticeable. But on an NA car, it's a lot more money to upgrade to a stroker kit. Would I rather spend $1500 more on the stroker kit, or have that car spend a few more hours on the dyno getting dialed in by someone who really knows what they are doing?

So that's my argument, there are better places to spend the money.

Kurt
 
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No, if both engines are set up ideal (i.e. the same compression ratio, and ideal camshaft), the difference between the two engines is 0 hp. The difference is how fast the engine has to turn before it starts sucking in more air than the heads can flow. The power produced is a direct relation to the amount of air and fuel coming in. So, let's say that a set of TF 170cc heads have the flow potential to make 350hp. The 302 is going to make that 350hp at 5500rpms, and the 347 is going to make that 350hp at 5000rpms. Those aren't exact numbers, but pretty close.

If you are talking about full out acceleration, like drag racing, it doesn't matter much, because clutch release is going to be like 6000 rpms, and from there on out, you keep it right in the powerband. On the street, the stroker engine is going to be a little more fun, because it's going to get into the powerband from low RPMs faster, theoretically. In an old Mustang on street tires, you are pretty much over the tire limit instantly anyway, so you wouldn't notice. On that size head though, it might not even be noticeable. But on an NA car, it's a lot more money to upgrade to a stroker kit. Would I rather spend $1500 more on the stroker kit, or have that car spend a few more hours on the dyno getting dialed in by someone who really knows what they are doing?

So that's my argument, there are better places to spend the money.

Kurt
Well either way the car would be tuned so be it 306 or 347 I would it would be Tuned to get the most out of it. And that 1,500 on the stroker kit would be just too be able to get the most out of a block in the extra HP torque. And that's providing a rebuild is needed but if I was going to do one I was thinking 331. I know people will say 347 because to maximize what you can get out of the block
 
Well either way the car would be tuned so be it 306 or 347 I would it would be Tuned to get the most out of it. And that 1,500 on the stroker kit would be just too be able to get the most out of a block in the extra HP torque. And that's providing a rebuild is needed but if I was going to do one I was thinking 331. I know people will say 347 because to maximize what you can get out of the block

What heads are you looking at? If you are looking at some really big heads, stroking the engine can really help with the block longevity by keeping the RPMs down. I like to keep my stock blocks below 6500rpms. That's pretty old school by today's standards. Money is rarely unlimited. When you say you are getting tuned for optimum, does that mean you are putting a piggyback chip on the factory ECM tuned by the best guy you can drive too, putting it on a trailer and bringing it all the way down to Orlando, or putting a full stand alone Holley system with wideband O2s on it? There are a lot of variables, and it comes down to goals and budget.

Kurt
 
What heads are you looking at? If you are looking at some really big heads, stroking the engine can really help with the block longevity by keeping the RPMs down. I like to keep my stock blocks below 6500rpms. That's pretty old school by today's standards. Money is rarely unlimited. When you say you are getting tuned for optimum, does that mean you are putting a piggyback chip on the factory ECM tuned by the best guy you can drive too, putting it on a trailer and bringing it all the way down to Orlando, or putting a full stand alone Holley system with wideband O2s on it? There are a lot of variables, and it comes down to goals and budget.

Kurt
To be honest I'm not exactly sure I mean I would love to just keep the heads and intake that I have and just use it on probably a 331. Having two other cars is not like I would really be trying to maximise the bill to be honest. And I'd likely be getting a chip tune done
 
To be honest I'm not exactly sure I mean I would love to just keep the heads and intake that I have and just use it on probably a 331. Having two other cars is not like I would really be trying to maximise the bill to be honest. And I'd likely be getting a chip tune done

Just add a power adder if you are connected to your parts at a spiritual level (like I am).

Kurt
 
No, if both engines are set up ideal (i.e. the same compression ratio, and ideal camshaft), the difference between the two engines is 0 hp. The difference is how fast the engine has to turn before it starts sucking in more air than the heads can flow. The power produced is a direct relation to the amount of air and fuel coming in. So, let's say that a set of TF 170cc heads have the flow potential to make 350hp. The 302 is going to make that 350hp at 5500rpms, and the 347 is going to make that 350hp at 5000rpms. Those aren't exact numbers, but pretty close.

If you are talking about full out acceleration, like drag racing, it doesn't matter much, because clutch release is going to be like 6000 rpms, and from there on out, you keep it right in the powerband. On the street, the stroker engine is going to be a little more fun, because it's going to get into the powerband from low RPMs faster, theoretically. In an old Mustang on street tires, you are pretty much over the tire limit instantly anyway, so you wouldn't notice. On that size head though, it might not even be noticeable. But on an NA car, it's a lot more money to upgrade to a stroker kit. Would I rather spend $1500 more on the stroker kit, or have that car spend a few more hours on the dyno getting dialed in by someone who really knows what they are doing?

So that's my argument, there are better places to spend the money.

Kurt

When talking about the heads by themselves, yes they can only flow one max amount of air on a flow bench. But saying the difference between said heads on a 306 cubic inch engine versus a 347 cubic inch engine is 0 horsepower, that literally makes no sense. Slap a Trickflow top end kit (stage 1 cam for discussion sake) on a 306, and you will net 280-290 at the wheels (most cases I’ve read). Put that same Trickflow kit on a 347 and you will net 330-340 at the wheels... How can you say all things being equal the extra 41 cubes nets a zero power gain? I’m lost here man.