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75 all orignal

STalon89

Full Member
Joined
Oct 15, 2016
Messages
311
Recently bought a 75 thats basically 100% stock. I want to freshen up the motor without getting to crazy and going down the rabbit hole with new parts. It has 37k on it and currently runs/drives decent. Just looking for some advice before I start digging into it
 

hyghlndr

Contributor
Bronco Guru
Joined
Jan 19, 2009
Messages
5,075
Loc.
Hockessin, Delaware
Post some pictures! If it's really that original, best to keep it stock for now until you really think through things. Doing bolt on bolt off things to make it run and drive better won't really effect the value.
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
9,044
If you're looking for a "bit" more umph, then getting more air/fuel in and out is all you can do on a '73 SMOG motor. 4bbl intake, 4 bbl carb, headers and good exhaust you will really notice the ability to get more rpm's out of it and a bit more power also... amazing how much help in passing or towing being able to accelerate from 4K- 5000 rpm helps. Otherwise, you have a motor designed for early emissions and they are essentially gutless...

Sounds like a good find. Have fun.
 

suckerpunched

Sr. Member
Joined
Aug 24, 2006
Messages
882
Post some pictures! If it's really that original, best to keep it stock for now until you really think through things. Doing bolt on bolt off things to make it run and drive better won't really effect the value.

yes I agree with this post pics, that would really help and what do you mean by freshen up the engine? pull it out and reseal it, new timing chain, oil pump, water pump. things like that I would do. If it has good compression, I would not rebuild it. Depending on condition on the entire rig, I would keep the patina and not restore it, that goes for the engine too. repainting the engine might look out of place if not doing a full restoration. Just my opinion.
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,200
The '72 and newer EB engines had emissions equipment and tuning that can be deleted to get the performance of pre-emissions engines. The timing of the cam was retarded at the crank pulley. A steel chain and sprockets with a 4 degree advance will fix this and provide the low RPM torque EBs need. There no need or use for high RPM HP in an EB. Any auto machine shop will tell you this. A simple tach function of an engine analyzer will show you that 99 percent of your driving is done at 1800-3000 RPM. That's where you feel any useful power increases. I also recommend deleting the EGR with a '72 or earlier intake. Finally a custom timing curve will wake up more torque and get better MPGs. Read this;https://www.fordmuscle.com/archives/2000/03/timing/index.php
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
9,044
I love blanket statements like this! -sarcasm intended.

QUOTE=jckkys;3257099]..

"There no need or use for high RPM HP in an EB. Any auto machine shop will tell you this. A simple tach function of an engine analyzer will show you that 99 percent of your driving is done at 1800-3000 RPM. That's where you feel any useful power increases." Read this;https://www.fordmuscle.com/archives/2000/03/timing/index.php[/QUOTE]

Guess I don't know what I'm doing, especially with my Bronco if I'm idling along or maybe reaching 1500rpm on the rocks for hours at a time or the other examples would be snow or sand wheeling when if you can't keep tire speed above 35mph (when actually moving at about 10mph) you aren't playing the rest of the day... and good luck trying to keep 4, 35-40" tires spinning in deep sand or 2-3ft deep wet sloppy snow when your engine can't rev above 3800rpm.

Just saying that a 5,000 pound vehicle isn't the same as some comparison about cars.

I understand what you're saying about a stock grocery getter doing ok with a narrow power band and minimum power but the days of smog motors with heads that don't flow, 28-31" tires, no p/s, no p/b is a thing of the past. That's why most restomods sell for more than stockers..
Most people expect some kind of power and convenience.

Not harping on ya but blanket statements about 170HP engines being all anybody needs kinda got me going I guess. Not many that actually wheel, whether light trails or nasty snow/sand like a 170HP if that isnt their only choice. I know guys that love theirstock HP rigs and I am not talking down or any any way saying their rigs are inadequate... I just experience and wheel in many areas where power is needed or you aren't going there. Thats all. Everybody has different wants & needs.
 
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jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,200
The idea that an EB, CJ, or FJ needs to rev over 5000 RPM is BS. My '68 289 was quite adequate for the uses of a 4X4. The 170 HP is something you pulled out of your ass. The pre-smog 289/302s were rated at 200-205 and worked very well. The owners and writers that drove them when new all knew this and no one found the power to be inadequate. The weak point if any was low end torque. Anything that promotes high RPM power hurts low end, ie 1500-3000.The promoters of headers, performance cams etc won,t even tell what their product does at 1500-2500 RPM where most driving is done in a 4X4. Get a classic Mustang or Corvette if you want a drag racer.
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
9,044
289 = gross HP
Post '71, 302's = net HP

3,000 rpm now it's 5,000 rpm

It's all apples and oranges.

I'm going to move away from this conversation since its being taken downhill rapidly and moving away from the OP.
 

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