"Free" HP?

[1slow95]

I got a stock 5.0 engine for my car and I'm looking for cheap/free mods that I can do before I drop it in. The main thing is I don't want to hurt driveability and I don't want to have the tuned.

Here's what I have in mind: Port the stock lower intake, retard stock cam 4*, bump timing 2-4*, shorty headers/full o/r exhaust. This should put me in the range of 215-230rwhp, but I'm not certain how the stock ecu will respond. It should be fine, but I want you guys' opinion before I do it.


In case you're wondering, I'm selling my stroker setup and putting the car back to stock. I'm kicking around the idea of trading it for a 03-04 Cobra. I'm tired of driveability problems.

 

[revhead347]

I don't think there is anything to be gained by porting the stock lower, since the restriction is on the exhaust side of the cylinder head. Retarding your timing is going to hurt power. You need to advance the timing about 4 degrees. As far as driveability goes, all the Mustangs I have worked on run smoother with the timing advanced over stock spec.

Kurt

 

[1slow95]

I've spent all morning reading tech articles from tmoss and there is about 10-15 hp to be gained from porting the stock lower intake.

You have cam and ignition timing mixed up. Retarding the cam shifts the power band higher... I know 4* works well with ported or aftermarket heads, not sure how much it will help with stock heads.

 

[revhead347]

I've spent all morning reading tech articles from tmoss and there is about 10-15 hp to be gained from porting the stock lower intake.

You have cam and ignition timing mixed up. Retarding the cam shifts the power band higher... I know 4* works well with ported or aftermarket heads, not sure how much it will help with stock heads.

You're right, I was reading too fast and was thinking ignition timing. I find it hard to believe there is any loss in the stock intake when the heads are so bad. But hey, it's worth a shot.

Kurt

 

[Dino Dino Bambino]

Free Modifications
Parasitic Horsepower Losses

 

[1slow95]

I guess my real question is will porting the intake and degreeing the cam cause any problems with the ECU where a tune would be required to fix it? I'm trying to avoid a dyno tune to save $500.

I think it will be fine, but my only experience with this car is going from stock to 450rwhp in one shot. I don't know how well the ecu responds to more than just bolt ons.

I suppose I'll throw this in here too...Do I need to remove the heads to replace the lifters? I don't on my 351, but it looks like there's a lot less room on the 302.

 

[revhead347]

I've pulled lifters without removing the heads, but it wasn't with stock heads. I honestly can't remember if you have to pull the heads.

Kurt

 

[hollywoodstang]

No, You don't have to remove the heads to take the lifters out

 

[earleys94gt]

I wouldn't think porting the lower intake would affect the ECU much, or at all, since the port work will be "downstream" from all the sensors, MAF, IAT, TB etc. But, I do know the lower intake is restrictive as hell.

 

[1slow95]

I wouldn't think porting the lower intake would affect the ECU much, or at all, since the port work will be "downstream" from all the sensors, MAF, IAT, TB etc. But, I do know the lower intake is restrictive as hell.

I've been doing a lot of searching and that's the same thing I came up with. It looks like as long as I don't max out the stock MAF/injectors it'll be fine. I'll go ahead and go for it.

I'm more worried about degreeing the cam causing problems...I think I'll go ahead and try that too. Worst case, I just have to pull the timing chain off and set it back to 0.

 

[90lxcoupe]

Put a manual rack on it, the powersteering is a big drain, ditch all of the smog stuff too

 

[1slow95]

I can't ditch power steering because I have hydroboost brakes. Although I'll probably go back to the vacuum booster when the 5.0 goes in. Plus manual steering sucks.

Smog stuff is long gone.

 

[earleys94gt]

I'm more worried about degreeing the cam causing problems...I think I'll go ahead and try that too. Worst case, I just have to pull the timing chain off and set it back to 0.

I did not degree it, but I had a Steeda 19 cam in my car and it idled fine. I think the lift might have more of an affect than degreeing it would.

 

[KamiKaziDK]

what about lightly porting the exhaust on your heads? Just getting rid of the exhaust bumps will help a lot, and they're easier to do than getting the inside of a lower intake.

 

[1slow95]

what about lightly porting the exhaust on your heads? Just getting rid of the exhaust bumps will help a lot, and they're easier to do than getting the inside of a lower intake.

I spent a couple hours searching on that the other day and I couldn't find a definitive answer whether grinding down the bumps helps or not. It looks like the gains are from the bowl work and not much from the port itself, which is more work than I want to get into.


I starting porting the intake last night. I did about as much work as I was comfortable with, now I need to order a longer burr to finish it up. I can't believe how restrictive the the front two runners are.

Since I have the engine this far apart, should I go ahead and replace the head gaskets? It has 120k on it.

 

[BlackVert]

What you are going through (getting sick of the drivability issues and finally deciding to ditch the car) is exactly why my #1 focus for my build was drivability. Even with big cubes, with the right cam and a good tune, it is achievable ... mine idles rock solid and does not buck at all, even when lugging up a long hill at 60 mph at 1500 rpm in overdrive.

Even so, I can understand your frustration and respect your decision (not that you need mine or anyone's approval for your decisions!). Best of luck to you, and I hope you are happy with the outcome.

I am considering pulling mine out and sticking in in a corner for eventual installation into the Fairlane. One way or another, mine is going to be sold ... either as is, or as a roller, or with a stock 302 ... I need to make good on my promise to my wife.

Back on topic ... most people agree that the single most restrictive part in our engines is the lower intake. Porting that should result in some decent gains.

 

[1slow95]

I built mine with driveability in mind too, but it didn't quite work out. I know my problem is in the tune and a few other misc things, like tons of exhaust leaks and a very touchy tb. I can lug it down to 1300 rpms or even less, it runs fine under load. Light load under 1600 rpm is where I have problems. It wouldn't be hard to make it drive right, but I'm tired of working on it and tired of dumping money into it. Plus with gas prices going up, 12 mpg is pretty rough.

Going back to a stock 5.0 is sort of a reset button for me. If I decide to keep the car, I'll go with a set of aluminum heads, aftermarket intake, and probably boost. Something that drives like stock but is still quick. If I decide to sell the car, it'll be much easier with a stock engine rather than a built engine with some issues that need fixed.

 

[1slow95]

Just cleaning all the crud out of the intake should free up 5-10hp at least! This thing is pretty nasty, but it's slowly starting to look like new. I have ports 1-4 pretty much done, I'll probably finish 5-8 next week. Any suggestions for cleaning out the upper intake?

Ordered some carbide burrs from mcmaster-carr, they showed up next day.

 

[revhead347]

Any suggestions for cleaning out the upper intake?

Extrude hone.

Kurt

 

[VibrantRedGT]

This is an interesting thread, going back to stock.

I can tell you about retarding the cam, it's a bad idea. Don't know if you were reading my threads 10 years ago in this forum but I did that with my Crower cam. I would have to rev the hell out of the car just to get it moving. The power didn't start until about 4500rpm, yes 4 degrees is that far up in the bandwith. It pulled to 7000 rpm and banged off the MSD limiter I had in it. I can tell you from experience it wasn't a fun time. I then changed it to straight up and never looked back, it ran great even with a blower. With stock parts it should be worse.