Have a couple grand to spend - more hp? - Page 5 - Vintage Mustang Forums
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post #61 of 69 (permalink) Old 07-22-2019, 01:37 PM
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Originally Posted by wicked93gs View Post
Sure, send me the link...we will see if they actually post up the dyno results on screen with the fan being the only difference between runs.

P.S. I am sure the fan DOES care what engine its stealing power from...a 460 has a LOT more rotating mass than a 289...it will be much more sensitive to reductions in that weight at 5000RPM

Here is one with a clutch fan vs electric:


A whopping 3HP gain...true...a fixed fan will be a bigger gain, still looking for one. I dont consider engine masters(or any other magazine) a reliable source for any data simply because they all try to sell their advertisers products. Its far better when you can find individual before and after dyno graphs.

That being said, there are plenty of reasons to go to an electric fan over a mechanical one...from space, to better looking, to better cooling and anything else you can imagine.
The weight of the fan is only a factor when changing the speed of the fan. When a fan is up to a given speed it is the pitch and area of the blades that determines the power to move the air. The same fan, running at the same RPM will require the same horsepower to run regardless of engine size.
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post #62 of 69 (permalink) Old 07-22-2019, 04:07 PM
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Originally Posted by jdub View Post
As for that being an "outlier" they also lost 24hp with a plastic flex fan and 20hp with a metal flex fan. The clutch fan did better but I still think it was a 14hp difference (need to rewatch the whole episode).
The Engine Masters episode is season 2 episode 20.

The word outlier means it's at the extreme end of the scale just as the 2 hp pull from the drifter kid was an outlier at the low end (and Im not sure his test was up to temp enough for his fan clutch to kick in). For those pulls not to be outliers they'd need to be more toward the average or the mean of the sum of the pulls.

For a better real world example I look at the usable power band for the kind of driving I am doing. If you look at the curves the biggest lost is at the top end and except for drags I don't see that as being a normal use case. When I'm in the top gear at 5k it's around 100 mph or so. That's when you want that extra power but for most people driving in the 2k range the loss isn't that big.
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post #63 of 69 (permalink) Old 07-22-2019, 04:50 PM
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Your ride sounds awesome, must blow your hair back. Send the cash on gas and attending show and shine with your parter having a good time dancing and parting. You have the total package now, enjoy it show it off.
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post #64 of 69 (permalink) Old 07-22-2019, 05:10 PM
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Originally Posted by wicked93gs View Post
I will believe this when I see a dyno graph proving it. Even underdrive pulleys which drop a significant amount of rotating mass(more than a fan) usually are good for only about 8-10HP. A radiator fan weighs about 3lbs or so usually for something like a flex-a-lit. At a rule of thumb of 3-6HP per pound of rotating mass...that's a theoretical MAXIMUM of 18HP that you could possibly gain....but as you will see, bolting on a UDP that claims a 10HP gain often gives you a real world gain of maybe 5HP.

If I took a plain jane 289 and removed the fan is that going to bump power from 225 to 255? I will bet you that it wont...I bet you that best you are going to see it jump to 235

It's not just about mass. Rotating mass affects acceleration a little, but what you're talking about here is *drag*. And a bad fan with no clutch attached to the engine can really thrash some air around, when it's spinning north of 7k RPMs. Since most water pumps have a smaller pulley than the crank pulley, maybe that's more like 10k? 12k? Anyway - that loud jet-engine roar on the front of the engine really can, and does, steal a lot of horsepower. Way more than you might think. And although the alternator itself will steal a little more power than usual to charge the battery, it's a tiny fraction of the direct parasitic loss you get when you step on the skinny pedal with a fixed blade fan.

It would affect low RPM engines less than high RPM ones, because HP is a function of how much torque it's using at a given RPM, and because the fan probably takes more torque (moving more air faster) at high RPMs.

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post #65 of 69 (permalink) Old 07-23-2019, 07:27 AM
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There was a test of multiple fans I saw recently with average HP loss, as well as various RPM points. The average and mid-RPM Hp loss was MUCH less then the peak RPM numbers always quoted. There's quite a few street small blocks that don't even get run to 6,500 RPM.

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post #66 of 69 (permalink) Old 07-23-2019, 09:41 AM
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Originally Posted by nrowles View Post
As title states I have a couple grand I can spend. This is probably a very broad questions and just looking for ideas. Maybe my best bet is to scan the forum thread topics but to be honest quite a few threads I don't understand pros/cons of what people are doing. So here's some info listed below. Brainstorming. I also would prefer not to add things that can be "finicky" and cause me problems. For the most part this car runs really well and I don't have any major issues. Fires up and runs without hiccup every time. I'm not interested in discussing body work and paint. Mostly I just hot rod around in 1st 2nd and a little bit of 3rd. I don't corner and I don't drive fast. I like to hear it rumble and I like to spin the tires. So what are some thoughts and options I can research?

My primary thought is more power because I like power but the problem is I bought this car built the way it is and the guy I bought it from was the owner after the build and he didn't get the specs. I also don't know the overall condition. It was built in 2005. I have done compression testing that turned out well but other than that I'm not sure. It runs very strong and my "gearhead" buddy called it a torque monster when he rode with me the other weekend.

*1965 Coupe
*351W - ~400 Engine hp
*Edelbrock Performer RPM Top End Kit - I'm not 100% on this one. Was told by PO it has top end kit with ported/polished heads. Intake is Performer RPM.
*Holley 670 Street Avenger - tuned well
*Bored .30 over
*Hooker Headers
*2 1/4" exhaust
*MSD Box/Distributor
*4 Speed Toploader - Not really interested in a 5 speed just to get overdrive. I like my toploader
*3.55 Detroit TrueTrac - gear swap to feel like I have more hp/torque? Rarely am I on the roads doing more than 55 mph.
*Car has old school traction bars and no issues with wheel hop
*Flex fan - never had any overheating problems even in 95 degree weather. Flex fan can be annoying though.
*Front disc - brakes manual - I'm fine with it
*Manual steering - I'm fine with it
*No vibrations

After typing this mess out I'm hesitant to do anything major with the motor because I don't truly know what makes it up or its condition. Is it a complete tear down to figure this out?
Would a leak down test give me everything I need to know on condition? Suggestions?

I'm thinking maybe a gear swap would give me the illusion I'm searching for. ??
Custom cam and some dyno time to really dial in the carb. Or a set of TFS 190's and a tune. Guessing either one could gain you 20-25 hp. You might find that since your combo is running so well that you will get to the point of diminishing returns on $$ spent--not really a bad thing but you will find out that you get to the point that you need to spend more and more to get a little more power at a certain pint.

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post #67 of 69 (permalink) Old 07-24-2019, 08:19 PM
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I'm not quite sure what the question is.
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post #68 of 69 (permalink) Old 07-24-2019, 10:24 PM
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Originally Posted by DaveHollis View Post
I'm not quite sure what the question is.
Money burning hole in pocket. Wants more HP. Were it me with that ride I'd take the $2k, top up my fluids, check the tires and road trip to Reno next month for Hot August Nights. For $2k you could get a last minute gouge price hotel, have a great time and still have money left over.

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post #69 of 69 (permalink) Old 07-24-2019, 10:40 PM
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I second the vote for the Holley Sniper and would add the Holley distributor so it handles timing too, throttle response and hp will improve and you can feel that, then I would look into a roller cam retrofit that works with your heads and intake, I know you have a cam but choosing a similar roller cam will broaden the hp curve and you can feel that too. This will take the 2k if you install yourself.

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