Supercharger or new engine? Thoughts?

[Jason Rowe]

Hello all! Its been a while since I have posted - so much catching up to do! I have an MK4 and it has a 5.0 engine from a 1994 Mustang. It was great 5 years ago when the car was first done....but I want more.

My question is - supercharge the current engine which runs just fine or get a new motor all together?

My fear about the motor is I would have to replace a lot more than just the engine (and I will have to pay someone to do the work). I don't want to sink 3000-4000 in a supercharger and then just turn around in a year or two and do an engine anyway.

Thoughts? (And thanks in advance)!!

[GoDadGo]

What about swapping out the 302 for a 363?

https://performanceparts.ford.com/part/M-6007-Z2363RT

It reduces the amount of modification under the hood, plus you can claim it is a well put together 302.

[NAZ]

Jason, when you start adding power adders like a supercharger (or turbo charger) you need to ensure the engine is built to accommodate the new power adder. Specifically, adding boost will require a compression ratio that will accommodate the amount of boost and live with the fuel available in your location. When I lived in Germany back in the 70's we had higher octane fuel available than what we have here in the states today. Where I live now the highest octane rating available is 91 and that would really limit the boost or compression ratio I could run on a supercharged old school V-8. Newer designed engines with better combustion chambers and engine management systems can get away with more than the old school designed engines we like to build for our hot rods and custom street machines. Also, depending on the amount of boost added you may find that the rotating assembly (crankshaft, rods, and pistons) may have to be upgraded to withstand the increased forces applied due to the increase in power produced. Simply adding a supercharger to an engine not designed for one can lead to detonation, catastrophic parts failure, or both. That's just the engine, you have to also look at the drivetrain to ensure it can handle the additional power.

The first thing is to look at how your current engine is configured as far as compression ratio and the rotating assembly. If it's a garden variety OEM built engine with cast crank and pistons you're better off purchasing a crate engine designed for a supercharger. Crate engines are a great value as they are usually less expensive than you can build a similar one for when sourcing all the parts yourself.

[AC Bill]

Perhaps you could just fix up the existing engine to give you some more poop, without having to add a supercharger? Larger throttle body, bigger injectors, performance cam, some ECM tweaking, etc. Depending on your existing rear end gearing, a lower gear ratio may pleasantly surprise you.

Depends on what your looking for performance wise I guess.

[RickP]

I suppose at some point we all ask ourselves the same question if we have an existing stock power plant. I agree with Naz in that if you start bolting on power adders, there is only so far one can go with the foundation you have under those adders.

When faced with the same dilemma, I decided to rebuild my own from what I had, a stock 5.0 with 87,000 miles on it. Not wanting to be faced with the same quandary if I out grew the engine, I decided to rebuild from the block up building a solid foundation along the way. It ended up not being the smartest econimal thing to do but the experience I gained doing it was priceless.

After taking the block to a machinist and verifying the block was a good candidate to build from, I had him stroke it to a 331 and install a new forged SCAT crank, rods and pistons. I won't get into the specifics of the motor build (topic for another day) but couple that foundation with a dual plane intake and some AFR heads and now your making big hp.

I wouldn't consider bolting a 3-5k super charger on a stock 302 without addressing what's at the bottom of your motor first.

[Shep]

Jason - My first build was a MK2. It started off with a 306. Bought the short block from Mike Forte, added Edelbrock Performer heads, Edelbrock intake along with upgraded TB, injectors, etc. Ran it that way for about 18 months and then dropped a Kenne Bell supercharger on top. That required upgrading the injectors, MAF and a few other minor tweaks. Kept the boost down around 5lbs, as the short block didn't have forged pistons. I kept the car for another 12 months or so and then sold it to another forum member. He owned it for over 6 years before he sold it. No idea who owns it now, but bottom line is it survived quite well under normal driving conditions. Now, if you're planning on drag strip use or any other extended high rpm activities, listen closely to what everyone said above.

[Fugi]

Jason,
I'm in process of having a 4.6 4v rebuilt and supercharged for my roadster scheduled for 10/1/17 ship. About 10 years ago I had put a ProCharger on a new, but stock (cast internals) 5.7 that was in a boat. After going through 3 outdrives and then blowing a hole in a piston I found some wisdom. It is not just the engine that needs to handle a significant boost in power (pun intended), it is the whole drive train. Not knowing what your goal is or where you are starting makes it difficult to make a recommendation. Have you run the car on a dyno? If not, that would be a good place to start. Then see if you can catch a ride in some other roadsters with different levels of power. Then you will know where you are and where you want to go. Only issues remaining will be time & money. There it is the "m" word, which ties directly to the other "m" word; Momma, as in; If momma ain't happy, ain't nobody happy.
Cheers,
Fugi

[Mike N]

Have you considered the spec racer top end kit from Trick Flow? I think that would give you exactly what you are looking for in a well put together and sorted package. You will also have plenty of first hand experience available on the forum from the spec racers.

[bobl]

First you need to establish a power goal. Then you can figure out a budget. Once that is done there are many experts on this forum that can get you headed in the right direction. 400 HP might be just a simple engine build. 500 HP takes a pretty high end build on a 302 based engine. Beyond that and you need big cubes or supercharger.

Bob

[edwardb]

Hey Jason. Haven't heard from you in a long time! We communicated a bunch when you originally bought that Roadster. Lots of good comments on here. My opinion FWIW. I wouldn't supercharge that stock engine. There are lots of discussions about what is the best HP for these things. If you're only doing street driving it's not easy to use much more than 400 in my experience. More is good for bragging I guess, but not easy to use. It's a question of driveability, traction, staying (reasonably...) within legal speed limits, even safety to a degree. With a few bolt-on's that are way cheaper than the supercharger you mention, you could get near that power level with the engine you have. Then there's the matter of how much a stock block with stock parts is going to hold up pushed past 400 HP. My engine builder showed me several examples of what happens to them. Think cracked open like an egg...

Personally I would look for incremental improvements like heads, intake, cam, etc. and you'll be surprised how much it livens up the driving performance. For a big jump, I'd be looking at a new engine and probably an aftermarket block like a DART or BOSS. Not cheap I realize. If you start down that path, don't rule out the Coyote. A lot of HP for the money and they run great. But don't overlook the advice about other things that might need changing when you significantly up the power level, starting with clutch and transmission. As I recall, yours was a donor build with pretty basic parts. Good luck whatever you decide.

[AC Bill]

500 HP takes a pretty high end build on a 302 based engine. Beyond that and you need big cubes or supercharger. Bob

And then along with that, a much stronger tranny..It's not cheap adding horsepower..:(

[GoDadGo]

What about getting a 363 short block and using your top end and other parts to save a boat load of money?

Ford Performance M-6009-363
Part Number: 397-M-6009-363
Ford Performance Short Block 363ci. Boss
Ford Racing Short Block
363ci. Boss
Cast Iron
4.125" Bore
3.400" Stroke
4-Bolt Main
8.2" Deck Height

I can tell you first hand that my 383 SBC has a lot more power than all of the 350 SBC's that I've owned & that's only a 33 cubic inch increase over what I've played with in the past.

$4,879.97 · Summit Racing
$4,452.00 · FordRacingPartsByDonW...
$5,252.99 · JEGS High Performance
$4,830.00 · Levittown Ford Parts
$4,899.00 · Dallas Mustang Parts
$6,000.00 · Autoplicity.com
$5,252.99 · eBay

61 more cubic inches (302 vs 363) has got to be an insane jump in torque, plus you won't have any intake valve shrouding with a 4.125" bore.

[Railroad]

347 crate, end of story.....

[42Bfast]

Not much to add to the wisdom already presented, but I will offer an attempt at subject matter humor......

From an anonymous quote:

"It's true, money can't buy happiness. But, it can buy horsepower, ...and that's pretty much the same thing!"

[Sanford]

If your engine is all stock. Try adding Heads...Edelberock RPM or the like and see if that is enough. Change Intake to Performer RPM and T-body. If it gets you where you want to be your good, if not then those parts will work on a stroker. Going to 3:55 gears will wake it up, depending on what you have now. There was a mod on the J-pipe that added HP by opening it up to flow freely into the sidepipes,,,,don't know what you have now....go to long tube headers....just some thoughts

[rx7922]

https://performanceparts.ford.com/part/M-6007-A50XS

[ProJoe]

Someone already said it, first figure out your ultimate power goals and work backwards from there. If a simple head/cam/intake change will get you your goals, it would save you a ton of money versus a full motor change even if the ceiling is higher than your goals.