SN95 Short Block Suggestions?
- Thread starter ry94stang50
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I'm trying to figure something out don't want to help then don't doesn't hurt me. And you take your own advice because obviously youdo the same or you wwouldn't know I post every five min....what might be old news for you is new to me. Don't like it don't read it..
Eco short tfs topend. Drive like a gentlemen and enjoy. Unless you're going for world speed record you'll be ok
Alright, I'll offer up my $.02 since I've been the "budget crate motor" route.
I bought the 320 hp P headed crate motor when I was in High School because I was afraid of building the motor I had. I didn't know any better and wasted a ton of money because it was an unecessary purchase.
These stock motors will run forever so long as you DO NOT put forced induction or spin them past 6500 ish. If you are that worried about the motor in your car now, pull it out and look at the bearings. Can't hurt and can be done in a day.
Save your $1k on the rebuilt short block and buy the TFS top end kit.
I bought the 320 hp P headed crate motor when I was in High School because I was afraid of building the motor I had. I didn't know any better and wasted a ton of money because it was an unecessary purchase.
These stock motors will run forever so long as you DO NOT put forced induction or spin them past 6500 ish. If you are that worried about the motor in your car now, pull it out and look at the bearings. Can't hurt and can be done in a day.
Save your $1k on the rebuilt short block and buy the TFS top end kit.
This isn't an argument but a question. So if I put a topend kit on my 90 that has either 176 or 276k mi I'm not sure which it should make power and run well? It cranks and runs well just seems a lil tired. Now it needs a couple things before I do this such as new rear main and as of yesterday new water pump gasket. But other than that its ok. I hear everyone saying the blocks will hold up but what bout the internals? Rings etc.
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Wow +1 on the payment plan. That makes things a lot easier for me lol me personally ifI'm gonna pay almost 2500 bucks on the tfs kit I'm not going to want to put it on my 156k mile engine. 2500 $ for a 347 stroker short block from woody iisn't bad at all. And the payment plan makes it all possible because after the down payment I'm forced to pay the rest sooner. Even makes a dart block possible but imo for my purpose a dartblock is way overkill.
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mikestang63
SN Certified Technician
As long as you check the motor first for compression, and it is in general overall good shape, then you should be fine. I think the point is, there is really not that much value in spending uber money on a production based 302 bottom end block when many people have run stock and JY motors well into the 300-400hp levels. If you buy the right top end kit and you end up going to a dart or other stronger block, you could then transfer over the heads, intake and such. Of course if you slap a new top end on a weak,tired bottom end it will just make the weaknesses worse. If you know the motor is tired perhaps the best thing to do is find a JY explorer engine, change the cam and heads, and have a nice little 260-270 rwhp motor for under a grand until you save money for the big build.
What heads would be better the tfs heads or afr 185s? Because it might be easier for me to buy the parts one by one instead of a whole kit.
I should have put an asterisk by my statement I guess. Every motor has been treated differently. I obviously can't say for a fact that your motor is fine, but if it isn't knocking or burning oil, I'd venture to say you shouldn't worry about it.
With that said, IF I was going to the trouble to put the top end kit on my car, I'd put new bearings in for cheap insurance. It's such a small expense relative to the top end kit (less than $100 to do it yourself) that there's no reason not to. And the motor is already apart.
On my junkyard motor that I am putting in my car, I did all new bearings. I looked at the cylinders and they were fine so I decided not to do rings. That's up to you though when you pull the heads. Again, it's cheap insurance, I just chose not to.
Some may say "Well if you are going to pull it apart, why not just bore and stroke it?" THATS where it goes from a couple hundred to a couple thousand. The parts may only cost you $999 or whatever it is, but the labor will get you. If you buy the TFS kit or piece one together, you can easily make 350+hp, and for proof I'll cite Nik's car.
I kind of agree. The only issue I have is by buying a JY motor, you have no proof that you've bought an engine in better shape than what you have without taking it apart.... Which brings you full circle back to "why not just take what I have apart and check it?"
For what you are trying to do, it'd be a wash. Find what you can get the best deal on and go with it.
Again, some will say "oh hogwash! XXX heads are worlds better then YYY heads!" But the truth is, for a mild HCI street car, they'll both do what you are trying to get at.
*edit - your camshaft selection is where you will make the biggest difference.
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oh hogwash! I don't really mean that... I just thought it'd be fun to say 
If you get it cheap enough, why not just stick it in and run it? Seen it done on my buddies Twin-turbo setup. Ran hard for 2.5 years until the day he sold it.
If you get it cheap enough, why not just stick it in and run it? Seen it done on my buddies Twin-turbo setup. Ran hard for 2.5 years until the day he sold it.
Man, if you're gonna go that cheap, you need to seriously consider either running the shortblock you have or going with a junkyard motor. With new stuff, you get what you pay for. You want a reputably built shortblock, Rick or Woody have great reputations.
V2SQ or newer vortech is designed to be quiet. But! You should really consider turbos, friend. More power at the same boost, WAY more torque, no sound at all until it starts to spool, and afterwards, the sound is f-ing music!
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For the first comment, yeah, but would it make the power level he was wanting to get at (Think I saw the 350-400 number thrown out??) It would take a little more work, right? Those are 320hp i thought.
For the second comment, this is a fact that I still fail to understand. I understand boost to be resistance to flow regardless of how it is introduced. Discounting the parasitic drag from the supercharger, how do you make more power from a turbo? I've read a few places that 10 psi one way is not the same as 10 psi the other way.
You said hogwash! Seriously the OP has said he wants a DD not worried about racing,etc but also wants 350-400hp and possibly a power adder. And cheaply I might add. As we all know none of this goes together. More power = less dependability. Not to say you can't DD @ those levels but I will say its not done cheaply.
HotFox
15 Year Member
I never said cheaply....I said as cheap as possible lol. And a supercharger is wayyyyyy down the road. Not anytime soon. A supercharger is years down the road. Basicly ill be happy with whatever bottom end I do decide to get paired with a good top end. Whatever power that makes is what ill have so 300hp? 350 if I go stroker?
Yeah, but in this case, it WAS my best friend. It's not a tall tale. I gave him my old incon twin kit, my old GT40X heads, and a few other things, and made recommendations on other components - nice friend, right? I know every component he had on the car, and I know he paid $50 for that shortblock. I helped him tune it through his Tweecer, and drove the car a few times too. I think the tune was never spot-on, but he actually had no problem when he outran me in my C5 corvette even though he was missing badly in one cylinder due to a faulty plug wire. The car still pulled hard. I'm sure he was making similar numbers as my older combo, which I pulled a best of 12.2@118mph at 9.5psi. I know you're just teasing with the comment, but there is some truth to guys speculating on stuff and talking about a "friend." He's got a username here, actually but prefers '03 Cobra and Lightning/harley boards.Man... If I had a nickel for every time I'd heard THIS story.
It depends on your definition of cheap, I suppose. One thing that's certainly true is it can be done in cheaper ways than others. I consider the capability of splitting the stock block power levels for a few grand very cheap. However, my favorite saying when it comes to this subject is "Cheap, fast, or reliable. You can only have 2." In this case, doing it the cheapest way means using stock block, stock internals, stock drivetrain, etc... You'll find a reliable 5.0 motor in a junkyard somwhere, but it's going to cost time to find, convert, and install. It may also cost time to find another if the first one doesn't work out. However, you can buy a few junkyard motors for the price of one new one. And, another advantage of a junkyard motor as a first project is that you can afford to make a big mistake. It'll just cost you another trip to the junkyard and 50-500 bucks.
Fox guys giving advice to SN guys! Carry ON!
Scott
5.0 guys giving 5.0 advice.
Regarding nice driving/idling NA pump gas street motors (not race motors), this is what you can expect:
1. 302 with cheap H/C/I = 260-280rwhp.
2. 302 with premium/expensive H/C/I = 290-340 rwhp.
3. 347 stroker with cheap H/C/I = 270-330 rwhp.
4. 347 with premium H/C/I = 370-410 rwhp.
The variance depends on peripheral parts, compression, tune, and cam aggressiveness.
With a blower or turbo, every one of them is going to be limited to the strength of the block. Only the amount of boost and agression of tune will change. On any of these motors, you'll be able to reach the limits of "reliable" power on pump gas. Thus, choosing to go forced induction is a significant factor if you care about your budget. It's also important factor in the compression and cam selection, and the MAF and injector used.
Combo #1 = junkyard explorer or your stock motor with some used heads/cam/intake combo, and you can make that happen with elbow grease a few hundred dollars. Whereas, combo #4 is probably a professional build with new components and is going to cost $7-8k, plus tuning and peripheries.
I don't think you've put thought into much other than the motor, but that's only a part of the costs. Before you go to big power, you need to look at the rest of the drivetrain, fuel system, chassis and suspension, too. Thus, my vote remains, stay cheap.
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It would only make that with boost, but the answer is absolutely. In fact, I think an explorer motor with cheap blower or turbo is probably just about the most cost effective way of maxing out the stock block.
Like me, you're an analytical guy. We like to think about textbook physics and to understand why things work the way they do. Many of the guys that build and race cars, even in racing applications, build based on experience. In the practical execution of just about anything in the real world, experience trumps theory. However, the inferences they draw from success can be misleading. The subject you just brought up is an example. They are right in a way, but their explanation is not satisfactory to an analytical mind. There are 3 reasons why on a given motor, a given boost may not produce the same amount of power: efficiency, parasitic loss, and other changes on the entire system in blown vs. turbo applications.
Efficiency: Boost vs. the amount of oxygen in an intake charge
Regarding boost and not considering the source, 10 psi IS 10 psi period. It's just an amount of pressure, which is essentially the force that molecules of air are exerting on each other. The force comes from molecules of air bouncing off of each other and against the outside of their "container." It's just the kinetic energy of all of the molecules in the container. You can increase the total kinetic energy in the container by either increasing the number of molecules or by increasing the temperature of them. The temperature, after all, is just the average intermolecular kinetic energy. In this given container, the intake tract or a cylinder if you prefer, we know the volume and we know the pressure, and so the final piece of the puzzle we need to determine the amount of air molecules and the corresponding amount of O2, is the temperature.
With turbos, you can get a pretty good idea of this temperature or the amount of air by looking at the compressor map. The compressor map tells you how much kinetic energy put into the wheel will be converted into actually compressing air instead of creating other unwanted forms of energy heat/noise/etc... To read one of these things, you have to know a little about your motor. You have to know at what RPM your motor will operate, and you also have to know the volumetric efficiency of the motor at that RPM. Based on those variables (RPM, VE, & displacement), you can calculate the volume of air a motor will move. Volume alone won't tell you the amount of oxygen, though. To get that, we need to know the pressure and temperature, too. Since we can directly control the pressure with a waste gate or pullies, the final variable is temperature. So, using this volume and boost, we refer to the compressor map to determine the efficiency. The lower the efficiency the higher the amount of unwanted heat produced. This heat finds its way into the air and into whatever is cooling the turbo. So, it's intuitive that the lower the efficiency of the compressor, the higher the temperature, the lower the amount of air/O2, and thus the lower the gross power produced. I'll define gross power in this case to be before any parasitic loss.
Parasitic loss
This is a little more complicated than people think. It's more than just the difference between robbing mechanical energy from the drive train instead of "wasted energy from the exhaust." It's also about the amount of energy needed to turn these wheels, screws, roots fans. We talked about how a wheel with lower efficiency results in higher temperatures at a given boost, but there is also something else going on here. Where is the energy for this higher temperature coming from? The lower the efficiency, the more energy needed to produce the same amount of boost + a higher temperature, which is kind of a double whammy because the boosted air with a higher temp from the less efficient wheel has less oxygen density. It's a triple whammy when you consider that the higher temperatures require less timing advance to avoid detonation. It's a quadruple whammy when you also consider that the energy from the blower isn't "wasted exhaust energy." Ok, enough with the whammies.
A centrifugal blower should actually require less energy to turn, because there is less rotating mass, and because it's directly linked to the kinetic energy from the crankshaft, but unfortunately the energy is coming directly from the power output of the motor instead of exhaust energy. Turbines are an added source of loss in a turbocharged system. Actually efficiency maps also exist for turbines, too. However, we don't look at them very often because too many of us consider it "wasted energy" anyway. It's a mistake though. The result of increased parasitic loss with a turbo is increased backpressure and increased exhaust temps. Backpressure definitely impacts power & valve train durability, and is too often overlooked.
Impact to system design: blower vs. turbo
The routing and blockage of the exhaust causes problems blower motors don't have to deal with. Additional backpressure and obstruction in the exhaust cancels out the advantage of exhaust tuning (exhaust scavenging/Helmholtz wave resonance tuning). Secondary effects on the system of running additional back pressure associated with a turbo include reducing overlap of the camshaft to avoid reversion. This could also theoretically have a negative impact on the tune, though I'd be talking out of my ass if I tried to explain the tuning effects. The reduced overlap is actually nice for guys with street cars, because reducing overlap has the added benefit of increasing drivability.
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