Souping Up a 4.9?
 

Hello.

Over the Summer I purchased Quaddriver's 1981 Ford F100. He had plans to soup up the engine this Winter and I would like to continue where he had left off. I ran the idea by my votech instructors and they seemed eager to take on the project this Winter (a plus for me, since I have no where to store the truck when the salt comes along). I've never rebuilt an engine. I have taken one apart and learned a thing or too, but that's it. Those were also V-engines.

Now, rebuilding the engines and returning it to its 1981 glory is all fine by me. However, I was given a set of EFI Dual Exhaust manifolds when I bought the truck. So, why not? Quaddriver said there were guides floating around on how to convert the EFI manifold to work with a carb'd truck and my instructors agreed it was possible. So, I wouldn't mind giving the engine a bit more power. With a small list of modifications, I was told it would go from 120HP to 200HP.

I was told to put a new cam shaft in (isky, I think), a new intake, and get an EGR off of an early eighties Mustang. That's another thing, I fear that I will put on more than 5000 miles a year and daily drive it, so it'll need to be emissions legal. For the exhaust, I was suggested to stagger two cats and have the pipes go into a single muffler, then return to two pipes.

I would like to keep the 4speed SROD in the truck. As of right now, it has an aluminum driveshaft and 3.55 limited slip in the rear. I would think that would be able to handle an increase in power. Quaddriver said he feels the Mazda 5speed may be better suited, but my instructors feel whats there will be able to handle it.

I have no idea about the carb. I assume it will need to be changed. It is only a 1bbl right now. I'm guessing a 2 or even 4? Other than that, I have no idea on the specifics.

I'm trying to educate myself a little bit more on this before we start tearing it apart come Winter. Not to mention, I'll have to secure the necessary parts.

So any advice would be nice. Thanks for reading.

First off....What's the trucks intended purpose? DD, Sunday driver....?


Go from there...Are you wanting reliability, MPG....Power? or just a good mix of all 3?

I think (Personally)-

-Cam
-Offy Intake
-600cfm carb (for power.....500 or so cfm for more MPG)
-A HECK of a port and polish on the head...
-Gasket match the intake/exhaust....(Leave the Intake runners sorta rough...It's better for fuel atomization....
-Shave the head a tad....Or get some flat top pistons....(For a CR bump)
-A timing bump
-Steel Timing Gears (The Phenolic toothed ones are crap......never know when they'll give it up....
-Hotter coil, plug wires.....

Just stuff I've gleaned from other builds, posts, etc....I'm in the process of a parts list compilation myself....But for an EFI build.....Just wantin' about 50-75-hp extra...Maybe more at a later date.....Still up in the air...

Well, I will probably be driving the truck more days of the week than naught. However, in saying that, I also have access to a smaller, more fuel efficient car I can use at my leisure. Fuel economy really isn't a huge concern to me (or else I probably wouldn't have bought a truck). I just would like to give it more power.

well you need to call my friend and make him an offer for the offy intake and the holley 390 cfm 4bbl - he is awaiting your call and will be generous.

I will give you the exhaust talk here rather than email:

your engine is failry close in size to the 5.0, but will run far less rpm. You want the exhasut to stay hot and fast as long as possible. expand the exhaust volume, like very large pipes, too many pipes etc, and it will expand and therefore cool, and hence slow down.

5.0 guys can run into larger pipes, but these are guys running 6000-6500rpm. It is likely you will never see north of 4000 often and prolly never over 4500.

the split headers flow way better than the 'log' in the truck, 2 small cats into one muffler and then 1 outlet pipe will get er done.

the mustang egr you want is the one from the 5.0HO 4bbl.

couple all this with the isky cam and you are good to go and it will still smell legal come testing time.

the camshaft and lifters you are gonna want new, tappet cams are horrible to buy used unless you can regrind a new base circle.

before you do this tho, head up to the ole keystone raceway on 'run what ya brung' night and get 3 passes in.

then do the same when you are done. it wont be hard to figure out your appx hp boost.

Quad-The 4.9 is EXACTLY the same as the "5.o"...Look it up....The 1995 and previous 302's were 4.9xx Litre engines....And people KILL themselves to gain 2 cylinders and .050l difference.....

Makes no sense to me....:-banghead

I don't know what you'd do with an EGR plate off a Mustang since V8s have passages cast into the heads/intake to get exhaust gas to the EGR valve on the spacer. I suppose you could machine it for threads and plumb something from an EFI exhaust manifold. Even then it might not mate up well with an Offy or Clifford.

Has anyone ever figured out a way to run an EGR with a 4bbl on their 300?

And for the love of God don't gasket match. Port matching is fine although not really necessary, but where anyone got the idea that gaskets make good templates for head porting I'll never understand. Ninety percent of what you can gain porting happens within ~1-2" of the valve seat anyway.

With a cam, intake, a little more compression, and decent exhaust you'll be spitting at 200hp. No worries.

Oh, and if you're planning to use one muffler just use single three-way cat. I bought the cheapest 2 1/2" three-way I could find on eBay ($35, maybe) and passed emissions here in Dallas with an Edelbrock 500 cfm, no EGR, no AIR pump. Dunno how different the standards are there vs. here.

If you're going to get two cats you should just run duals back instead of marrying to one muffler and splitting it back. JMO.

The exhaust manifold I have for a split exhaust is from one of the EFI trucks. My truck is carbeurted. Quaddriver would know more about this, I'm just going along with it and trying to understand all the information.

What is gasket matching?

Gasket matching is when you make everything the same diameter/shape of the gaskets.....