Turbo on a '96 4.9, questions(seriously doing it)

[Dirdy Dan]

This isn't a dream build or some idea i'll never do, I am doing it. I have a '96 F150, 4.9 and I'd like to add around 5-8psi to it. I am completely new to turbos but have done some research already. I'm looking for some more power for towing and a little boost in mileage. The truck is a 5-speed manual. Some questions though...

A hx35w or hx40w for a Cummins seems fairly cheap price wise. Will it be too large for my goals? If it is, can anyone reccomend another cheap alternative?

The motor im putting together has stock compression pistons and a Comp. 260H-10 cam. Is oversizing the valves or putting larger rockers on really going to make a noticable difference with this cam/turbo combo? I will be doing some port work to the head.

How big is too big for an intercooler?

Anyone know of someone who has successfully had their OBD-II '96 truck re-flashed for a turbo? I've got a hold of places that will do it, just be nice to skip past any known problems others have had.

24lb injectors sound about right?



I'll be on here a lot trying to get this done. And appreciate all info and advice.

 

[Emerald 74 4X4]

If I remember right, the HX35 was similar in size to a Garrett T04B, which is what I have on my 300. I am using an intercooler that is 3.5 inches thick, 32 inches wide and 10 inches high. not sure how good of a job its doing, but it was originally for an 2003 International with 6.0L turbo diesel. it has 3 inch inlet and outlet.

Good headwork to decrease as much as possible the chance of detonation due to hot spots is critical on an engine like the 300 where it in't designed for a turbo. I run max of 5 psi boost on 87 octane. I can run 8 psi on 91 octane. If I would have known better before, I would have done a little more headwork in the detonation department.

I have a Megasquirt II running my fuel and ignition. If you can get the EEC-IV (or is '96 EEC-V?) to run on a turbo, then you have a lot of it tackled. The stock will not handle much over atmospheric pressure.

You'll need to upgrade the fuel pressure regulator to allow for a 1:1 boost:fuel pressure increase over atmospheric. I have 36 lb/hour injectors in mine, and I think they are a bit big. The stock fuel pump is 58 psi, as opposed to all other Fords which run 45 psi. This makes your average injector flow rate go up because of the increased throughput. So the stock 300 may only have 13 lb/hr flow rate injectors, but thats at 40-something psi rated, not 58 psi. It increases to somewhere around 17 lb/hr at 58 psi. Use a calculator (Google injector flow calculator) and figure out what you need.

Not sure if the MAF will cause any issues. You may need to convert to a speed density, not sure about the Ford ECM with MAF and pressures above atmospheric.

 

[Dirdy Dan]

It is a EEC-V, OBD-II system. And what hot spots? I didn't know these heads had that problem. Is there larger benifit to changing to stainless valves or just leave the standard ones in?

These 4.9 EFI trucks have the exact same fuel pump as the v8 ones. Its the regulator thats different. And IIRC, the v8 trucks have a 45psi static pressure and run about 32-38psi at idle and as low as 25 at WOT. They come with 19lb injectors. These 4.9s come with 14lb injectors. Yes, they have a 58psi static pressure, but usually run around the high 30s to low 40s. The ratings aren't too far off.

From my reading, i was to understand that I could get this ECU re-flashed with a programmer.

 

[Emerald 74 4X4]

Polishing the chambers keeps any detonation down by eliminating hot spots from peaks in the casting. I have a detonation problem unless I run higher octane fuel, and I think most of it has to do with unpolished combustion chambers. At 7.8:1 compression ratio, you wouldn't think I would get a lot of detonation.

 

[Turbo_B]

I will get uncontrollable detonation around 10 psi on 93 octane. 8psi seems to be about the limit on my stock head.

I use 36lb/hr injectors with a Mustang SVO regulator. the stock regulator maintained about 45lbs at idle and would rise to about 60 before the stock fuel pump ran out of breath. then drop to about 52psi. 7 psi was about what the stock pump could handle.

If you are ambitious - check these guys out--> http://www.moates.net/ford-pre2005-c-63.html

FYI, the 12cm^2 HX35w with a non pulse paired manifold will start to spool around 1800rpm. If you try to use the internal wastegate you will have boost creep issues, use a 34mm flapper valve for a DSM and drill/blend the WG opening to about 1.12 inches. I also welded material onto the turbine housing cover and ground into the cover to allow the valve to swing farther open.

Easier but more expensive is to use an external wastegate. But I did manage to get the internal to work properly.

 

[Dirdy Dan]

Polishing the chambers keeps any detonation down by eliminating hot spots from peaks in the casting. I have a detonation problem unless I run higher octane fuel, and I think most of it has to do with unpolished combustion chambers. At 7.8:1 compression ratio, you wouldn't think I would get a lot of detonation.

So just the light roughness of the cast is what makes the bad hot spots? Thats no problem for me to smooth out. What about those quench groves? Bad idea with these heads?

Basically, with out spending a fortune, i'm currently looking at stainless valves, hardened pushrods, moly rings, and a really good set of bi-metal bearings. Along with ARP hardware.

I might also look at doing some work with the stock exhaust manifolds(I have 2 sets). And if detonation is a problem, what about fabbing up some oil squirters?

 

[Emerald 74 4X4]

I went with stainless valves to better withstand the heat and ARP head studs and rod bolts. Everything else is stock engine components. The reason being my engine is not a high revving engine, so most all the stock components are fine for it. The factory main cap bolts are also quite stout. The weak points with a high performance/turbo is the head gasket, hence the head studs, and possibly rod caps due to the extra force being applied to the crank through them. I figure the rod cap studs are just security and don't cost a whole lot.

If you are planning to rev high, other parts such as roller rockers, pushrods, etc, etc will definitely come into play.

 

[Dirdy Dan]

With my searching for SS valves, I got nothing that directly fit. Do you have to buy longer ones and have them re-cut or custom order them?

I wanted to use ARP main studs, too. I'm a little leery of re-using ford bolts as I've broken a few of them during rebuilds. Plus, I've torn down motors with them stretched out. But the engine I'm doing a refresh on was just rebuilt 40k ago with all new bolts. So I guess unless I stretch one, I'll stick with them.

Also, if I can't do SS valves, would polishing the surface help out?

 

[Emerald 74 4X4]

I was able to find some back cut swirl polished valves from Manley that were slightly longer than original. Since I have the adjustable 3/8 straight rocker studs, I was able to get away with a longer valve. I believe "SI" has valves of the correct length though.

As far as Main bolts, a long time forum member and drag racer with the 300 "The Frenchtown Flyer" states he uses stock bolts even on some of his racing engines he builds. He says he has never ran into a problem with them. Do a little search on here and you might find the thread that tells you that. I definitely trust his word, knowing his background and experience with the Ford 300.

 

[Turbo_B]

Be prepared to do some work on the oil pump and the stud under it if you use ARP main studs.

the thread "turbo 300 in a F150" has some pictures of this.

I am not sure how good the Ford bolts are but I figure the studs are cheap insurance against a tow home and another machine shop bill.