Engine swap: Intake Manifold Compatibility??

jimvsmij

New Member
Mar 28, 2011
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Hello,
I have an Austin Healey replica with an old, tired, 289 in it. I am working on a 4.6L SOHC engine 2-valve (PI heads) out of a 2004 f-150 that I will replace it with when I am done rebuilding it. The problem that I know I will be facing down the road has to do with the intake manifold. The F-150's intake is tall and I don't want to cut a hole in my hood to get it to close. I believe that a mustang intake must not be as tall. Can anyone in here tell me a recommended intake that is the least tall either from a mustang or otherwise that will fit my heads? Any info will be much appreciated. Thanks...

Jim
 
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Will a '87-'93 Mustang's 5.0L HO EFI fit in one of those replicas? If so I would think a 4.6L with a Mustang intake wouldn't be a problem height-wise. You wouldn't want the tall truck intake anyway, the Mustang intake is a better performance piece for a sports car.

What about width? I assume you've measured and it'll fit between the fenders? A Mod motor is a bit wider than a Windsor 5.0L
 
@ Rick 91GT - Do you know what year mustang where their intakes will fit my 2 valve PI heads?

@patman0911 - I don't know the dimensions of the 5.0L that you mentioned. The Healey's has a lot of room under the hood. It is long and wide. It was made to use Mustang II parts for suspension, steering, etc so it is as wide as a Mustang II. It's just not as tall as an F-150 so I need a shorter intake manifold..
 
Nice seeing you again Trinity!
You guy gave me so much good info on that last post.
I decided to stay with my F-150, 2 valve and not go all crazy with getting a DOHC as some of you suggested. With our new baby I don't want to start diverting too much funds into this project and I don't need crazy horsepower in a 1900 lb car. I did get my hands on a really good conditioned Teksid block for pretty cheap though, so I will attempt to swap blocks as I rebuild the engine so any advice there if you have any experience...
 
Good memory trinity_gt.

Yeah, 260+ HP in a <2000 lbs car is going to be plenty of power :D

@ Rick 91GT - Do you know what year mustang where their intakes will fit my 2 valve PI heads?

@patman0911 - I don't know the dimensions of the 5.0L that you mentioned. The Healey's has a lot of room under the hood. It is long and wide. It was made to use Mustang II parts for suspension, steering, etc so it is as wide as a Mustang II. It's just not as tall as an F-150 so I need a shorter intake manifold..

Lots of kit cars and replicas love using Fox-body drivelines so I thought the 5.0 HO might be a good reference point. If that kit is Mustang II based than it's harder to say - a carb & cleaner sitting on top of the intake, probably not a lot of difference but it'd be good to measure first. Remember, the Mustang II's engine bay had to be redesigned to fit the already pretty tidy Windsor 5.0L for 1975 (no V8s in '74!) but the Fox-bodies will take a big block without too much trouble.

For mock-up, you can get a plastic NPI intake, throttle body and elbow off a 96-98 Mustang, or a 96+ Crown Vic/Grand Marquis/Town Car or Thunderbird/Cougar for next to nothing at your local pick-n-pull or someone would probably give you a cracked one - the height will be the same as a PI intake for measurement purposes. You might even get lucky and find a PI intake off a late model CV/GM/TC at the junkyard - all passenger car PI intakes are the same. I'm pretty sure I saw some fairly recent police interceptors at the yard last time I was there.

1999-2004 Mustangs have PI intakes with 2002-2004 being more desirable due to the revised aluminum coolant crossover tube. I think the Panther triplets got PI intakes in 2001 and the revised intakes probably in 2002 also.

The 2001 Bullitt had an aluminum intake manifold but it's not worth worrying about unless you're building for show - it's expensive, it requires a lot of extra bits to convert over to and its gains over a plain old plastic PI manifold are minimal.
 
@ Trinity - What do you mean when you say Bullitt variety? Is that a different type of intake manifold?

The 01 Bullitt Edition Mustang came with a different intake than the run of the mill GT:

m5lp_0203_01_z+bullitt_mustang_intake_manifold+.jpg


This would be a bit different under the hood than the standard GT manifold:

m5lp_0203_02_z+bullitt_mustang_intake_manifold+.jpg


I don't have the measurements though so I don't know which is lower-profile. As well, finding the parts for a Bullitt intake -- the manifold, the throttle cable etc will be far more of a challenge than a standard GT intake.
 
Since you're planning on building your own short block, I'd suggest getting some flat top pistons from the 96-98 cobra's. IIRC it's only a 3cc dish and would bump the c/r up to 10.5-11.0:1. If you had the pistons cut w/ valve reliefs and installed a nice pair of bumpsticks, you'd have a very nice power curve.
 
@patman - I'll start searching for those intakes. Yeah but I have a carb and cleaner sitting on top of my 289 right now and the hood just barely clears. I know that the F-150 is taller than the carb and air cleaner so I know I need something shorter. The width seemed to measure just fine with plenty of clearance. Maneuvering it through the narrow hood opening might be a challenge and there is a possibility that the steering rod might need to be diverted some. Worst case scenario is that I will have to take apart all the fiberglass panels around the engine to get it in.

@ trinity - The billutt does look shorter but I don't think I will consider it unless the GT manifold does not fit.

@N8Dogg - So how much benefit do I get from switching to those pistons. Sounds like your suggestion would cost a couple of thousand more than what it is already going to cost me, unless you know of a cheaper alternative. Don't get me wrong though, I'd like to build up the engine so that I can have options to upgrade it later, such as maybe at a later date putting in more aggressive camshafts but, not if it is going to be crazy expensive because then it would have made more sense to have just thrown out the F-150 engine and started fresh with something already having more potential such as a DOHC engine.
 
@N8Dogg - So how much benefit do I get from switching to those pistons. Sounds like your suggestion would cost a couple of thousand more than what it is already going to cost me, unless you know of a cheaper alternative. Don't get me wrong though, I'd like to build up the engine so that I can have options to upgrade it later, such as maybe at a later date putting in more aggressive camshafts but, not if it is going to be crazy expensive because then it would have made more sense to have just thrown out the F-150 engine and started fresh with something already having more potential such as a DOHC engine.

Well if you look around your local salvage yard it shouldn't be difficult to find an engine out of a Mark VIII (DOHC 32 valve 4.6) for around $300 (they're everywhere up here in MN for CHEAP). That block is the aluminum teksid and these engines are so reliable it's likely the entire rotating assembly is in good shape as well.

If you went this route you'd just have to remove the rotating assembly and have a machine shop flycut the pistons to give you more clearance if/when you decide to upgrade to different cams. You would only need the heads and timing components from your F-150 engine and all of it will bolt right on to the DOHC 4.6 short block. Even if you just used the stock PI cams you'd benefit from the higher C/R and with the flycut pistons you could probably advance the PI cams a few degrees and see some additional gains. It would be a torquey little 4.6 with that high c/r and like I said if/when you decide to upgrade to different cams you'd have a very streetable car that could easily make over 300 RWHP. Keep in mind you'd also be saving weight with the aluminum block (although its not much, every lb counts especially in a little car like you have)
 
So I bought some 550 deg engine paint. I'd like to paint the timing chain cover and the valve covers to make the engine look better since I have the parts off. Does anyone know the best way to clean these part to be ready to be painted? Some one at my work said sandblast with some kind of nut shells and someone else said sodablast. Should I invest in a Sodablaster? Maybe I can use it to make the aluminum block and heads look new too.