Explorer Motor Swap Questions

BKM48198

15 Year Member
Jun 7, 2008
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Ypsilanti, Michigan
My 5.0 in my 90 GT has seen better days and I'm looking for a different motor, I can get a running motor from a 97 Explorer with the GT40 heads and intake for $400. If I get that motor is it worth swapping in my cam to that motor or are they about the same? I want this as a daily driver vehicle rather than a race car but don't want less power than I had before when my motor wasn't smoking. Any help would be appreciated.Thanks.
 
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I "think" you can just do the cam swap, and then its good to go. There is definitely a difference in the cam, not sure about the pistons though (if they are fly cut, forged, etc etc) Someone else can answer that.
 
Pistons are the same hyper units found in 92-95 gt's. The explorer's cam is a truck grind meant to make tq below 2500 rpms. You can use it but you will suffer as you go up in the rpm band.
 
New valve springs are a must. Even the stock HO cam has more lift than they're explorers springs can safely handle.
The ho cam runs well with the gt40 setup but since you have maf running a tfs1 or an Anderson cam would be a great idea.
 
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X2 on the cam and springs change. The exploder cam and springs are meant for low rpm cruising. Swap in a TFS1 cam and spring kit and you'll have a nice little motor.
I have to do this an inexpensively as possible so I'll probably swap in my old HO cam, I wish I could get new parts but money is a big issue, my wife has MS and a lot of doctor bills. I'm getting the motor this weekend and probably won't put it in for about 2 months so I have time to try to find some deals on parts. I'm in my 50's so I am not planning on street racing it, just want a dependable motor with decent power. Are there any valve springs that I should look for or are they all about the same for a DD? I don't want to go cheap and have problems in a year or two.
 
I would highly suggest taking the heads,off and getting them cleaned and to have the springs done. Tell them what cam you plan to run and they will set you up
 
I have to do this an inexpensively as possible so I'll probably swap in my old HO cam, I wish I could get new parts but money is a big issue, my wife has MS and a lot of doctor bills. I'm getting the motor this weekend and probably won't put it in for about 2 months so I have time to try to find some deals on parts. I'm in my 50's so I am not planning on street racing it, just want a dependable motor with decent power. Are there any valve springs that I should look for or are they all about the same for a DD? I don't want to go cheap and have problems in a year or two.


I'm all for cheap power, but the springs on those heads are total junk. Leaving them in woth a different cam and you are going to run the risk of springs floating, binding, breakings and bad things happening. IMO, either keep the stock explorer cam or spend the money on better springs.
 
I'm all for cheap power, but the springs on those heads are total junk. Leaving them in woth a different cam and you are going to run the risk of springs floating, binding, breakings and bad things happening. IMO, either keep the stock explorer cam or spend the money on better springs.
I really don't want to spend $ 160 on the tfs-2500100 spring kit if I don't have to but I don't want to have a lot less power than what I had.......are there less expensive springs that would work good with a stock HO cam on the gt40 heads? I don't know much about valve springs and what is good or bad.
 
The tfs kit is good stuff and not that bad of a deal, shop around a bit and you might find it for less (iir it was about 120 when I got mine 2 or 3 years ago).

Also, im not 100% sure but I think the stock e7 springs will swap over if youre sticking with a stock ho cam, but new springs are worth the coin to give you more room later down the line and to make sure the old ones aren't worn out.
 
Going to play the Devils Advocate here..... Whats the exact lift differences between an HO cam and an Explorer cam that would seriously REQUIRE a spring change???? Guy is just going to cruise around in the car anyways, probably will never upgrade to the point some of us would. I don't see him bouncing off the rev limiter here.
 
its been covered before, not sure if I read it in here or over at corral, but the overall lift on the stock HO cam is more than the the springs are rated for. If you never rev it I am sure they "might" hold for a period of time, but any sort of spike in rpms could very well float the valves and muck up the pushrods.
 
Going to play the Devils Advocate here..... Whats the exact lift differences between an HO cam and an Explorer cam that would seriously REQUIRE a spring change???? Guy is just going to cruise around in the car anyways, probably will never upgrade to the point some of us would. I don't see him bouncing off the rev limiter here.
i have both the ho and explorer cams (as well as a beat-up tfs1) in my garage, if i had my calipers here (and i've got three pairs at work :( )i'd measure the lobes and see what the difference is (times 1.6 for the rockers). if nobody finds it by monday ill bring a pair home and measure it. it wont give duration or anything, but it should give me max (lobe) lift.
 
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Just talked to the guy that was selling the motor, he started pulling it today and found a cracked block so now I am looking for another motor, should I just look for a motor from a Mustang or is the Explorer motor the better way to go? I did find a b cam and springs for $175, is that worth getting for an Explorer block?
 
I actually just did some searching, and in everything that i've found, Nobody has suggested, or even mentioned changing valve springs if you're just swapping an HO cam in.

I say why take a chance.

http://www.fiveohinfo.com/performance/gt40-gt40p.html

). Alex's Parts (alexparts.com) is another great place to look for a drop-in spring package. They offer 3 different GT40/GT40P drop-in spring kits ranging from $97-$115, with claims supporting up to 0.600 lift! A bargain indeed!
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The exploder cam is less than .450 lift and designed for 4000 rpm shifts. The stock H.O cam is aroound .480 lift and designed for 5400 rpm shifts. Use the junky exploder springs and you leave most of the power on the table, plus run the risk of valve float and PTV problems.

But here's the real question. Why on earth would you want to leave in any springs that are over 15 years old? The seat pressure is probably 75-80 lbs at best.
 
Just talked to the guy that was selling the motor, he started pulling it today and found a cracked block so now I am looking for another motor, should I just look for a motor from a Mustang or is the Explorer motor the better way to go? I did find a b cam and springs for $175, is that worth getting for an Explorer block?

B cam? oh my... the B Cam cures cancer, male baldness, dandruff , and 3 out of 4 dentists prefer it. What springs are they? You need to get them tested for pressure.

It depends on what your goal is. The reason to use an Exploder motor is for the heads and inake- essentially a GT40 package- however, you need to swap the springs as stated or IMO why bother. If you have another $175 for the cam and springs then buy the exploder motor, throw in your stock cam or a TFS 1 cam and the TFS springs. The stock exploder motor makes less HP than the stock mustang motor due to the weak springs, cam, and exhaust. If you are truly on a budget, find another mustang motor and be d0ne with it.