5.0 build in 1990 Grand Marquis

[90merc]

Ive been doing alot of reading and have alot of questions. My plan is to build an engine that hopefully makes 300hp. I would like to do this on a budget.
Would my best bet be to buy a used Explorer engine and convert it to a carburetor? Should I upgrade the cam? What should I do? Thanks for the help.

[1990LTD]

a question, first - Why do you want to convert it to carb? Must it be carb?

[88mercgrandmarq]

the cheapest things i've done to gain hp on a budget too is to upgrade the air intake with a cold air one and with headers

[90merc]

I just figured a carburetor would make more horsepower

[79lincolnlover]

If you convert it to carb, you'll have to use premium gas. Most regular gas nowadays has Ethanol...

[pantera77]

I just figured a carburetor would make more horsepower

A properly tuned EFI engine will make equal too if not more power.

[1990LTD]

A properly tuned EFI engine will make equal too if not more power.

+1


300hp at the flexplate is attainable with an explorer motor, some porting, and an aftermarket cam. merc91 has a modified exploder engine and makes around that much power.

[johnunit]

spend your money on heads. 1500ish spent on good AFR165s or TFS170s will go farther than any other use of that money. If you are going aftermarket heads, which I would very strongly recommend, an explorer motor vs. a mustang motor are pretty much a wash. If you're going to be swapping engines, look into a higher stall torque converter. Giving a company like Dirty Dog Converters a call will give you an idea of what you need/want in that department.


In a small block ford, that's the restriction point. for a real crash course in how to make great power out of a 5.0, try sbftech.com. A lot of people on here go over there when they want to learn from the experts. Just keep in mind that some of what they say in regards to "streetability" and compromise assumes 3000 pound weekend car, not a 4000+pound daily driver.


What are your goals with this car? "300hp" (to the crank or wheels?) is a bit hard to relate to the actual performance of the car. Do you want to run 15s in the 1/4? 14s? 13s? How regularly will this be driven? Do you have to/want to be emissions compliant, and if so is it visual, sniffer, or both?

[zoomie]

if your going to use spray forged pistons are a realy really good idea.....also putting bigger valves and bowl work are awsome with gt40p heads,which are good for on a performance budget, AFR165 heads are awsome if going aftermarket. aftermarket cam yep that is fun idea too, however it all depends on what exactly you want to do.

[90merc]

I will be using it as my daily driver during the summer. There is no emission testing on cars older than 96 in Mass so thats not a problem. I'd like to try and use the stock heads and rotating assembly from the explorer motor because I know I wont be spraying it. So with that being said how much power can I expect from that engine with some head work and a mild cam?

[johnunit]

with a well-matched cam, some good porting, and a nice exhaust (aftermarket headers, 2.5 inch or larger piping, free-flowing mufflers) 300 to the crank is certainly doable using GT40 or GT40p (explorer) heads.

[Mercracer]

Ive been doing alot of reading and have alot of questions. My plan is to build an engine that hopefully makes 300hp. I would like to do this on a budget.
Would my best bet be to buy a used Explorer engine and convert it to a carburetor? Should I upgrade the cam?.

Yes and Yes. Easy to do. No porting is necessary. The only head work necessary is a valve spring upgrade. An easy way to pick up CFM if you wish is to run a set of undercut valves. Ferrea are available for a reasonable price. A cam change and a carb intake such as a Stealth or Performer RPM will get the job done. You can safely spray an Explorer motor with up to a 150 shot so long as you are pulling timing and running a quality ignition. I would not spend a penny on EFI stuff for a budget build where emissions are not necessary. You will spend more money for less performance. Engine work without gears and exhaust will be a waste. Spend money on your engine after working on the rest of the car first unless you can afford to do it all at once.
I am willing to bet that your entire budget is less than $1500...

[N A]

90Merc: I'm in Massachusetts too. I also have a '90 Merc. Stick with EFI. I'll be starting work on my GM soon. If you need any help or advice, just holla.

[Mercracer]

Stick with EFI.

This thread is in the performance section....

[90merc]

Wouldn't throwing on a carburetor be a lot be alot easier than getting all the necessary parts to to use EFI? I don't care about emissions or cold start up. All I want is the most power. How are the stock rods and crank in the Explorer 5.0 and would it be worth upgrading the pistons?