1970 Bronco Sport Engine Swap Questions

[chrlsful]

swap in the 6 for real tq...
Sorry - outta line there...
Lets C what U got when it comes home !

 

[jckkys]

I'm sure the "look" trumps any practical considerations or someone else would have suggested smaller tires.

 

[PhillyBronco]

I'm sure the "look" trumps any practical considerations or someone else would have suggested smaller tires.

There should be a way to not have to compromise on the ‘look’ to get the desired performance. After all, if the ‘look’ weren’t a consideration I likely wouldn’t be tinkering with a 50 year old truck in the first place!

 

[PhillyBronco]

Hey Philly, welcome to classicbroncos! Sounds like you just bought the Bronco too then? Haven't driven it yet?
As someone already said, a Bronco with 3.50 gears and 33 inch tires may very well feel underpowered. But yes, by today's standards they surely are, especially if saddled with mis-matched parts and such.
Hopefully the seller was telling the truth about such things as the rebuilt motor in the first place! But now that's a moot point anyway, as you have effectively more than doubled it's power output!
Stock, a '70 would have had about 170hp or so (205bhp "GROSS" was it's rating, but we now use "NET" ratings which are lower, but more reflective of the real world). The '70 also would never have had an auto trans from the factory, so who knows until you get it.
Either way though, the comments about proper gearing in the differentials is very important. Lower gearing removes some stress from the engine and everything else in-between it and the tires. But nothing wrong with waiting and seeing how yours plays after you get it and if you like it just fine.

Does the engine have a new flexplate with it? Is the torque converter a new one with the engine, or are you talking about the one that's already in the Bronco?
Just wondering about bolt patterns and tooth counts. Broncos use the larger 164t flywheels and many of the cars use the smaller 157t version. Then the Bronco C4's used two different torque converter bolt patterns over the years. And with a swap like your '70 would have, there's no telling what is in it until you get it apart.
So take those things into account when you start wrenching so you can check them ahead of time and not let them add frustration and time to your build.

Should be fun! Let us know how it goes (especially with the new engine!) and post up some pictures of it when you get the chance. We love to see new Broncos!

Good luck with it.

Paul

Paul, I’m assuming the new engine will require a new torque converter. What stall speed do you think is appropriate and can you recommend a brand?

 

[jckkys]

Compromise? The huge cartoon tires look silly too. What are you compromising on? A childish concept of what makes a truck look "cool" vs. a truck that looks and is capable?

 

[PhillyBronco]

Compromise? The huge cartoon tires look silly too. What are you compromising on? A childish concept of what makes a truck look "cool" vs. a truck that looks and is capable?

There really is no need to be unpleasant. I don’t know what you think you are gaining by being a troll on this thread.

Let’s agree to disagree.

 

[Justafordguy]

You will have no problem getting the performance you want with the new engine and the proper gears.

I think 33" tires look better too.

 

[chrlsful]

even "purpose built" can B based on opinion (however math duz not lie). Y the guide on rear gear ID above.
Personal taste is based on ones own internal process. Look at some of the architecture, hair styles, clothing'n furniture !
As one who used his bronk 33 yrs in the woods for income generation I can feel superior to all the recreation vehicles & fashion statements here. I would not think it wise to use those factors seeking to divide us, compete, or put down others.

"...There should be a way to not have to compromise on the ‘look’ to get the desired performance...."
there is - as every decision beyond the straight oem is a balance. As seen in the discussion - some balance one over the other (fashion statement v performance). Because the auto is a system, a change in 1 prt effects all the others.

Ideal? PPP - pre planning B4 performance my ol machine shop instructor said to us (due ur due diligence 1st). Plan, gather info, complete that w/full info - excicute fully all the way thru w/o change. I have seen too many hack jobs by those who change their mind mid project. My suggestion (unless experienced w/auto restomod) is do nothing for 6 mo 2a yr, but drive. Gather info: 1) abt the ride U have on-line, in books, on the net; 2) frm the actual rig underneath U. Save money (again - unless more wealthy than me) & compare "what U have" w/the possibilities for 'what U want'. Make that plan including budget, etc. Some are more carefree drivers, good. Some R more "into it", good 4 them too - that's Y we got chocolate & vanilla...

If U have more money or want a specialty rig (a bronk is not, its multipurpose - not good at any 1 thing, that's Y the huge mods U C sometimes) ID the RPMs 90% of the driving will B. Get a cam for that range, build the engine (octane, compression) & suspension breaks, ad nausium the rest each component selection of the system - around that. HTH, not hurts.

 

[PhillyBronco]

Thanks for the advise! I just ordered a 2000 rpm torque converter that I am told will be ideal for this engine.

 

[Rangerbj]

Have you bought the motor already? I had a nightmare 347 stroker from them that was a disaster. Had Chevy valves and destroyed a piston in well under 10K miles with only easy street driving.

They guarantee their engines for 50,000 miles. Did you get a new engine?