motor and torque question

[daves bronco]

ok motor guys I took out the 170 in my 66 I know I want a v8, toyed a little wiIth the coyote motor idea, but it is going up in cost. asked around about local builders, one guy says good, one says bad. So I have been looking at blueprint, tri star, and atk create motors. however when i read other threads alot of you say the cams are wrong for a bronco, and we need a low end torque. Is the low end torque for off road purpose? I plan on running mine 90 to 95 percent on the road, with no hard offroading. Am i going to be unhappy if i go with the 347 or a 351( 3.5 sl and a 1 inch body) from one of them? Is it going to be stuck at a stop sign until i get to 3000 rpm? I plan on running a auto trans with a d20 but i do have a np205 i could throw in. 35 inch tires and what ever gears are correct. I live in Seattle if someone know of a good engine builder.

thanks for you input dave.

 

[Digger556]

Many make the mistake of judging a cam solely by its claimed HP and torque numbers, but you have to ask yourself "at what RPMs do you need power?"

A 351 is a great engine choice once you get around the fitment issues, but it only needs a mild cam at best. My Bronco came with a built 351 that had a fairly aggressive cam. The numbers it boasted were great on paper, 440HP 450 TQ, but if you looked at its power band, the cam was designed to make power between 2600-6500 rpm. Well I cruise 75mph at 2500rpm, so the engine was barely breathing at the engine speed I needed the power the most.

This made it a real pain to drive on the street. I swapped in a more mild cam that hit peak torque ~3500rpm. The truck is more driveable and has MORE power between idle and 3500 rpm then the old cam did despite giving up 75-100 HP @ 6000rpm (which I will never hit). Honestly I could have gone even less aggressive and been fine. Driving a manual trans, I want the engine to pull from 1000rpm up to about 4000 rpm. After that I'm shifting.

 

[sykanr0ng]

A local engine builder is a better choice in my opinion.
If you have a serious problem with an engine built by a company far away from you the return shipping comes out of YOUR pocket.

 

[Timmy390]

Many make the mistake of judging a cam solely by its claimed HP and torque numbers, but you have to ask yourself "at what RPMs do you need power?"

A 351 is a great engine choice once you get around the fitment issues, but it only needs a mild cam at best. My Bronco came with a built 351 that had a fairly aggressive cam. The numbers it boasted were great on paper, 440HP 450 TQ, but if you looked at its power band, the cam was designed to make power between 2600-6500 rpm. Well I cruise 75mph at 2500rpm, so the engine was barely breathing at the engine speed I needed the power the most.

This made it a real pain to drive on the street. I swapped in a more mild cam that hit peak torque ~3500rpm. The truck is more driveable and has MORE power between idle and 3500 rpm then the old cam did despite giving up 75-100 HP @ 6000rpm (which I will never hit). Honestly I could have gone even less aggressive and been fine. Driving a manual trans, I want the engine to pull from 1000rpm up to about 4000 rpm. After that I'm shifting.

I couldn't agree more. The Bronco is not a 5.0 mustang. The Bronco is brick with tires on it. Most of the time, BIG tires. It's very hard to push the brick down the road due to wind resistance and big tires. That's where all the torque you can get comes into play.

I built a 351W over the past year plus. Stock bottom end with a Comp 35-349-8/XE264HR power between 1,500-5,500rpm. Any lower then 1500 you give up other areas on the cams I looked at but I'm EFI so it might be different with a carb.

On the desk top dyno, my combo makes right at 320HP and 440fpt. The torque curve stays above 380fp between 2000-4500RPM. Which is great because most of the time on the street with the stock 3 speed, I'm at 2K plus RPMs or just under 2K. I push the gas and it GOES.

Tim

 

[Broncobowsher]

Since you are starting with a blank slate, start with a 351W. Even a stock engine is a nice balance for a Bronco. Since you don't have any 302 parts to start with, you can avoid the un-necessary expense of a stroker kit to try and get the torque you will want.

I've always used local machine shops and put the parts together myself. So I can't recomend any of the drate engine nor a local builder for you.

The big issue with buying an engine is they are sold on the highest HP number for the least $. Often done with sourcing some sub-par parts and often at the expense of drivability. You also have to ask what grade of fuel are you planning on using. As much as I love adding a bit of squeeze in the compression ratio as it does make the engine perform better overall there are limits before you start needing to go for better gas, and race gas is too pricy to drive on the street. So some questions to ask the crate engine maker/engine builders are "what grade of gas is that on" or better yet, "what engines are available (or can be built) to run on 87 octane". Be careful about the "pump gas" phrase as 93 can be considered pump gas and may be un-obtainioum in your area. There are getting to be places that offer 100 octane at the pump now as well. Also ask what kind of manifold vacuum to expect at what idle speed? Getting an engine that idles well and pulls strong vacuum at idle on 87 octane all hurts the peak HP potential. So that is where the true builders come out, they can make a drivable engine that still has good power.

 

[Attac]

If you don't go with a 351 and are going to buy a crate motor you can call Blueprint and tell them you are putting it in a bronco. They changed the heads and cam on the 331 stroker for me and didn't upcharge. I have had good luck with mine.
That said you just cant beat the 351 for torque if you are starting fresh
Chuck

 

[daves bronco]

k guys thanks for the input, so is there going to be problems fitting a 351 in with only a 1" body lift, or do I need a two inch. I feel like it is such a crap shoot for local engine builders. one guy i talk to says oh that guy is great. then the next guy says oh hell no.

 

[TDubya]

If you don't go with a 351 and are going to buy a crate motor you can call Blueprint and tell them you are putting it in a bronco. They changed the heads and cam on the 331 stroker for me and didn't upcharge. I have had good luck with mine.
That said you just cant beat the 351 for torque if you are starting fresh
Chuck

Do you have the specs on the cam and heads they put on your engine? Just want to know the difference from their advertised components.

 

[Timmy390]

k guys thanks for the input, so is there going to be problems fitting a 351 in with only a 1" body lift, or do I need a two inch. I feel like it is such a crap shoot for local engine builders. one guy i talk to says oh that guy is great. then the next guy says oh hell no.

Swapping the 6 for an 8 has it's own set of hurdles with radiator and motor mounts. They there's the issue of what trans you plan to run.

As for the 351W, EFI or carb? I ask because the answer is different depending on what parts you plan to run. For me, the 351W with GT40 lower intake and 97 Explorer upper and T-body didn't fit with a 1 inch BL the way I wanted it configured so I scooped the hood and modified a hood brace to get it all under. My hood was nothing special and I like the look of the scoop anyway.

People are doing both EFI and carb under the hood with only a 1 inch BL. It all depends on the part you plan to or want to run.

As for local builders, everyone builder I know has people say good and bad things about them. I went to the "go to guy" and still had an issue where a head was cracked and magnafluxing didn't catch it. It took time and energy and cost me some money figuring it out but in the end the machine shop/builder did me right once the problem was found. While I was and still am frustrated a the situation, I also understand "things happen" and every builder out there had had something come back with an issue at some point in time. I like local because I could go back to the shop, talk to them one on one face to face and even took the block and heads back when having my issues.

Sourcing a block can be as easy as finding a van or truck with a bad trans. I got my 96 E350 van donor for $800. Once I parted it out and scrapped it, I got a running 351W roller block, EFI harness (I had to modify it) and front dress for $65. The cracked head set me back but I pulled a set of GT40P heads at the local yard for $30 each.

Tim

 

[thorgan]

When I was running a carb on my 351W-based 427, I was able to get it to fit under the stock hood with only a 1" body lift. I was running an Edelbrock Performer manifold and carb and ended up using an air filter housing from a 70's Lincoln with a big block. They basically shrink-wrapped those filter housings around the carb for hood clearance to that giant engine.

 

[daves bronco]

timmy 390 I defiantly want a auto so i was looking at buy a new aod or 4r70w. I was planning on using the fitech setup.

 

[Timmy390]

I don't see why FiTech and the right air cleaner wouldn't fit if a carb and 4 B intake works.

Might have to search and source an air cleaner but I'm sure others like thorgan can put you on the trail of something.

It is a tight fit on the D side between the firewall and the head as well as the brake booster bracket but mine clears with no issues. Stock ford valve covers on my rig.

If you get GT40P heads, you'll need to run Bronco shorty headers.

Tim

 

[Attac]

Do you have the specs on the cam and heads they put on your engine? Just want to know the difference from their advertised components.

TDubya
I will have to dig out my papers and dyno sheet.
I know the cam is basically what I have always called a rv cam.
My motor still put out advertised HP at top rpm but it dropped the torque curve sweet spot about 1000 rpm.
I will try to post pic of my sheet tomorrow.... just brought my mom to hospital so doubt I will be home any time soon.
Chuck

 

[jckkys]

With the stock 4V intake and the late stock air cleaner there's no need for any body lift or butchered hood. With EFI, you will likely need one or both. In my Bronco it's the intake that comes closest to the firewall not the head. I also found that the Edelbrock Performer EGR intake works as well, being only about 1/4" higher than the '69 Mustang 351W 4V intake. It was a little extra work to plug the EGR hole in the carb mounting pad. The Mustang intake needs one bolt hole on each corner plugged unless you use early 351 heads.

 

[DirtDonk]

It's good to hear about Attac's experience with Blueprint. There have been several discussions about their stuff with very impressive dyno charts included, but few (if any) real world feedback comments after the fact.
The dyno charts were showing some pretty good low rpm torque curves even with their off-the-shelf builds. Great to know that they will work with you and change some of the details.

Thanks for the feedback Attac. If you had a build/buy thread about the engine, did you add the updates after getting it all up and running?

Paul

 

[Godwick]

For what it's worth, I went with tristar and got their stock roller 351w with some upgraded internals and the intent to swap the top end out for something less restrictive when I get to the point where I don't have to drive the bronco everyday. The first engine they sent looked like hell, but they took it back and shipped a new one no problems. Customer service seems spot on and no trouble with this engine going on about 1500 miles.
One thing I do wish is that I didn't stick with stock cam or heads. I'll be getting to that asap. Broncos should be fast in my opinion. All cars should be fast in my opinion.


Sent from my iPhone using Tapatalk

 

[Attac]

It's good to hear about Attac's experience with Blueprint. There have been several discussions about their stuff with very impressive dyno charts included, but few (if any) real world feedback comments after the fact.
The dyno charts were showing some pretty good low rpm torque curves even with their off-the-shelf builds. Great to know that they will work with you and change some of the details.

Thanks for the feedback Attac. If you had a build/buy thread about the engine, did you add the updates after getting it all up and running?

Paul

No Paul,
Basically in my feed I just had put that I had gotten a crate motor and had installed it.
When I called Blueprint I had questions about the motor and told them that it was not going in a mustang but a Bronco instead. I asked if they needed me to send my oil pan to them to use. One of the guys there is a bronco guy so they told me they would make sure that they put the correct pan on it and also they were going to change the cam to produce a lower torque range . He also suggested using a crossover pipe to also help with power at lower rpm.
I ordered the motor about 6 months before installing it so that I could get all the other parts installed and do any mock up.They had broke motor in already but When I did my start up, they had put a tag on motor saying to call before starting. When I did they started my warranty that day. Not the day I received it. So far nothing but good experience with them.
I am gonna dig out my dyno sheet and post it.
Chuck

 

[tabascom16]

So here is the low down. Horsepower is derived from torque. Formula is: (Tq x RPM)/5250. Look at every dyno chart and HP and torque cross at 5250 RPM. High horsepower engines move the torque curve up in the RPM band to get the best torque at higher RPMs while sacrificing low RPM torque and thus low RPM horsepower.

That being said, almost all crate engines have a fairly aggressive cam because that peak horsepower number sells!

I built my 408W about 11 years ago. If I had to build an engine today, I would get a Coyote motor with the aftermarket Ford wiring harness. The F150 one has some milder cams and can be purchased for a lot less than a Mustang engine. A friend of mine picks them up all the time for $3000ish. The variable cam timing goes to great lengths to replicate low RPM torque of a mild cam, and high RPM horsepower of a large cam.


If you don't like all the modern electronics, get a 351W, stroke it to a 408, and get a milder cam. If you want low end streetable power there is no replacement for displacement.

 

[LowCountryEB]

If you don't go with a 351 and are going to buy a crate motor you can call Blueprint and tell them you are putting it in a bronco. They changed the heads and cam on the 331 stroker for me and didn't upcharge. I have had good luck with mine.
That said you just cant beat the 351 for torque if you are starting fresh
Chuck

Attac-

I have talked with BluePrint at least 4-5 times about making ANY changes to their engines (cam, etc...). I read your comments above last night, and called BluePrint again today to ask them about your comments. Each and every time I have talked to BluePrint, they say they do NOT change out ANY internal components of their engines. You say that you are going to upload your specs and dyno sheets on this thread, but you haven't. I'd love to see your sheets and verify the changes you made to your engine. I'm planning on ordering my 408 at some point this week. Thanks!

 

[Attac]

Attac-

I have talked with BluePrint at least 4-5 times about making ANY changes to their engines (cam, etc...). I read your comments above last night, and called BluePrint again today to ask them about your comments. Each and every time I have talked to BluePrint, they say they do NOT change out ANY internal components of their engines. You say that you are going to upload your specs and dyno sheets on this thread, but you haven't. I'd love to see your sheets and verify the changes you made to your engine. I'm planning on ordering my 408 at some point this week. Thanks!

Sry LowCountry,
When I first saw this thread I was sitting in the hospital with my mom after taking her to the ER. After being there about 8 hrs I guess I got around someone with the Flu because the next day I was in bed. anyway for the last week I haven't done anything. I am out and about a little at work today so when I get home I will go to shop and find my envelope that they sent me with the motor. I might have even written down the name of the guy I was talking to. I didn't even ask about the cam change when I talked to them. I was calling about the oil pan and clearance issues because of it going in the bronco. The guy I was talking to suggested that they use the other cam. Blueprint is actually a member on this forum and I have pmed to whoever posts for them about offering bronco specific motors.
With all of that said, I think you are going the right route with the 408. I am going that route with the next one. If you want good info on the 408 get in contact with BAX on here.
Chuck