Opinions - Turbo or Heads/Cam on 351W?
 

Hi everyone,

I'm trying to decide which route to take on my '85 bullnose.

It has the 351W HO engine in it at the moment, but I would like more power (lots, actually - but I have a budget :( ) and are trying to work out the best way to go.

It's a basic supercab F150, with a 4" lift and C6 (pics at the bottom of the post for reference). The truck will be driven 2-3 times a week to work (30 miles each way) and will have A/C and power steering. I'm not sure what the diff ratio is in it (not near the vehicle to check) but it cruises @ around 2,200 rpm at 60 mph on the freeway.

The truck will also be towing a 21ft boat (bowrider with an inboard Mercruiser) which weighs around 4,500 lbs incl. the trailer. The truck has a Class V Curt trailer hitch.

That being said, do we have anyone on this board that has built a 351W using aluminum heads, cam and an intake? If so, it is much of an improvement over stock? I'm looking specifically at an Edelbrock top end kit (Part # 2092) and would like it quick to drive. I think 0-60 in the 6 to 6 1/2 second range would be quick enough for me.

I'm not looking to do any work on the bottom end as pulling the engine out isn't really practical for me at the moment.

On the other hand, do we have anyone that has thrown a turbo onto a 351W and used it in an OBS?

Any tips on the pro's/con's of each would be really appreciated, incl. any areas that were an issue during the install.

https://cimg0.ibsrv.net/gimg/www.for...655e5c13e8.jpg

1985 Ford F150, 351 Windsor, C6, White.
https://cimg5.ibsrv.net/gimg/www.for...ee2e62b064.jpg

1985 Ford F150 Supercab 2WD. 351W, C6.

Very nice truck! IMHO, given a budget, and that I don't have turbo experience, I would do a cam and head combo. Save up a little bit more, and I would stroke the 351 to 408. This is my eventual plan for my truck, for now the little 302 does what I need it to. If you have worked with turbos before, go that route. Keep in mind the stock heads would more than likely need to be upgraded for a turbo add-on anyway. Also, depending on what that rear end ratio is, you might want to look into changing it. Not too hard, and can really help in the pulling dept. 4.10 ratio would be a good bet for me.

Thanks 4X484150!

I was thinking along the same lines regarding the heads - at some point, they'll need to be upgraded.

Heads do not need to be upgraded necessarily, since you are forcing the air in the engine, any restrictions in the head while not good, are sort of "covered up" by running the engine under boost.

The problem with running a carbed gas engine under boost is the complexity of the whole thing. There are lots of little problems and modifications that need to be done to the carb setup and the fuel pump to make it work. That is why boosted engines are more common now, fuel injection and computers make it easier to manage and properly fuel a boosted engine. Best to stay with the old school heads and intake for now.

One thing you need to keep in mind is with a turbo or blower is the compression ratio you are starting with.
Most start with low compression say in the 8's or lower if you are going to really boost it,
So with either you have to figure what the boost will be and what the compression you end up with.

Now can your cast crank, rods and don't forget the pistons take this extra power / boost?
As boost PSI goes up so does the temps in the combustion chambers and melts pistons.

I bet you want more power because the truck is a dog off the line or pulling the trailer?
It is because of the large tires and the rear gear you are running.
I would put 4.10 maybe even 4.56 gear in the rear and run a Gear Vender over drive unit.
OR
If you like the way it runs now, RPM on the high way, run a Gear Venders under drive unit as it will help you get going from a stop and pulling the trailer. Once moving shift out of under drive and run the normal C6 & rear gear.

I think the under drive would be cheaper and less work than a turbo and the motor stays stock.
Dave ----

Thanks Franklin - you make some good points. I'm leaning towards the heads/cam combo. In your opinion/experience - do you think 400hp/400 ft lbs will produce strong performance in an F150 frame?

FuzzFace2 - thanks also for the suggestions and point of view re the turbo setup.

I had considered the overdrive after seeing David Freiburger use one on an episode of Roadkill some time ago as I think it's a great option, but my only concern with the Gear Vendors overdrive unit is that while it all looks heavy duty, it costs around $3,000 (based on their website), and when you add in the cost of a new, shortened tail shaft that will be needed (around $300? ballpark), new u-joints, and then add to that the gears in the diff, we are getting beyond my budget. In comparison, the heads/cam/intake kit is $2500 and a remanufactured 650 cfm Edelbrock carb is another $350, totaling a little less than $3,000 out the door...

However, I agree and can 100% see the benefits for my application. Thanks for suggesting it.

You would only need to do rear gears if you did not like the RPM when on the high way the way it is set up now.
If you like the high way RPM and just need more pull off the line then the GV under drive and rear drive shaft is all you need.

Even a intake, carb, cam will not give the pull off the line like a lower rear gear or the under drive unit.
Just my thinking
Dave ----

Before you do a top end kit or anything else do a compression check. If you are not at least 150 PSI across the board rebuild the engine.

If you are thinking of 400HP/400FTlbs the stock C6 won't live long behind it. Rather than the expensive GV unit I would opt for an E4OD/4R100 with a stand alone controller. You will get the benefit of the steeper 1st gear over the C6 adjustable shift control so you can dial up tow/haul, street or strip.
Actually I would consider that for the first mod. Do that then do the engine. The trans up grade will show immediate improvements with towing, fuel economy and off the line performance. When the engine is done later on you will get the full benefit of the engine up grade immediately.

Matt, you do bring up a point I did not think of till your post, a lower first gear in the auto trany.
Wonder what the $$ are to do a E4OD/4R100 with a stand alone controller would be?

As for the C6 not living long with 400/400 I don't buy.
They were used in all kinds of cars and trucks from the factory and I am sure guys used them in their hot rods that had to be pushing over the 400/400 mark.
Dave ----

To get good performance from that engine, you will need to consider the complete package, gearing being most important, and you may need some stall in the torque converter. It sounds like you want to use a standard already tried engine build, so you should be able to get some horsepower versus torque versus rpm charts for your combo from other builds. You should be able to take this and see where you are going to be making power, and what you combination of tires and gearing you have now will put you in that curve. These trucks are heavy, go through the air like a brick, and you have large heavy tires. Your engine mods are going to raise the horsepower curve up the rpm scale some, so to get the most out of that engine, you need plan your final gear ratio carefully.

You can do it in stages though. You could do the engine first, then the gearing later. If the cam will need some stall in the converter, you need to install one of those while the engine is out.

Just know when you add more stall, slip, you build more heat and converters & tranys do not like heat!
Now you have a heavy truck to start with, then add the larger tires and pulling a trailer and that all adds heat to the trany. Do you have a large external cooler on the truck now? You should and if you add more stall you may need 2 of them to keep the temp down.

The factory built this as a "package" and you start changing that you have to think what will that change of the package?
ie: larger tires make it harder to get going, slip in the trany = more heat.
They also make it harder to stop so larger brakes would help but will not fit the wheel so you need to look at different pads & shoes to take the heat and a way to keep that heat down, ducts to get cool air to them?
Now add rain & ducts and you have wet brakes = not good for stopping.

Also why is it everyone wants more power and go faster but never thinks on how to stop it???
See you change 1 thing what that out come does to the package now?
Dave ----

Thanks for all the great opinions - you've all given me a lot to think about.

I like the idea of a built 4 speed with the right gearing in the differential after I get the engine built and think that is the direction that I'll head in. I was Googling built E4OD's and they run about $1,400 + time to install which isn't too bad for a rebuilt transmission IMHO and, as Franklin2 said, I can build it over time. BTW - does anyone know what else I need for a bolt-up application? If not, I can Google it.

The thing is, I also need to change the radiator (gets to the "L" of the temp gauge when driving on the freeway for more than 20 mins), install a new AC condenser, new carb with linkages (choke isn't working on the current carb) etc... all of which can be done when I take the old ones out to do the cam/heads/intake - which is sort of what led me down that path. Then, when I'm not messing with the engine and making everything greasy, I can clean up the interior (fix drooping headliner etc...), and make it really nice to drive.

That all being said, I drive pretty light - 1/2 throttle maybe 3/4 sometimes, but mostly just cruising in urban areas and on the interstate getting to and from work. I only tow the boat once or twice a week and are working on getting some brakes for that trailer - which i got some great advice here about, a while ago before I bought and put on the hitch.

For whatever it's worth, I bought this truck b/c my Dad had a bullnose Bronco years ago and I love the looks and simplicity of the design, plus the F-series has more functionality than a Bronco for my non-commercial needs. For example, 95% of the A/C components are in the engine bay - as opposed to being buried behind the dash which takes 4 1/2 hours to pull out and another 4 1/2 hours to put back together like in some other cars. Plus, I just really like getting into this truck and I'm getting to a point in my life/age where that's what I care about - not having the latest thing.

That being said, I'd like for this truck to be peppy around town and if I want to peel out, it will need to do that. I don't need to pull 12 second 1/4 times. For me, I rarely go above 4,000 rpm anyway. I figured that a 400hp, torque-y V8 would accomplish that.

You guys are great and I really appreciate the info. If there is any more that you would like to share, I would really be thankful for the insight.

Double Post

Absolutely you can stuff a C6 behind 400Hp 400Tq motor. But not a bog stock one from a 351W with some mile on it. Just as a bog stock AOD wont survive behind a hopped up motor but a modified one can.

The C6 got it's bullet proof reputation when they were running Type F fluid. The Dexron/Mercon variants don't have quite the same durability. I have never have a Type F C6 fail on me. But have had a few Dexron Mercon variants bite the bullet. In both trucks and cars. You would think that C6 behind a 140hp 302 should be indestructible but they are not.