Engine Rebuild Time

[Chief Master Sergeant]

The knock is getting louder and seems to be coming from the lower end of the engine. I've decided to have the motor rebuilt locally, but need some advice. I'm running the fuel injection from a 90 Mustang and was wondering if I should have anything special done with the motor to help with this set up??? I'm almost positive this is the original motor. Any suggestions are welcome. Thanks in advance.

 

[Timmy390]

I don't know of anything special machining wise. Just standard work.

If you're looking for better performance ditch the smog heads and go with some E7's or GT40 heads and a cam of your choice. Be sure to calculate compression when changing the heads.

If the tune on the ECM is stock then it's already tuned for the E7's and should react well to a better cam. If it's been tuned for the 72 heads and cam then it will probably need a new tune.

Tim

 

[Chief Master Sergeant]

I don't know of anything special machining wise. Just standard work.

If you're looking for better performance ditch the smog heads and go with some E7's or GT40 heads and a cam of your choice. Be sure to calculate compression when changing the heads.

If the tune on the ECM is stock then it's already tuned for the E7's and should react well to a better cam. If it's been tuned for the 72 heads and cam then it will probably need a new tune.

Tim

No, it was never tuned. That might be part of my issue.

 

[blubuckaroo]

How many miles in the motor?
Any repair history?
It's amazing how long a small block Ford will last when given proper care.

Post photos.
We love carnage!

 

[DirtDonk]

Is it a V-belt or serpentine configuration? If V-belt and maybe an old damper, try removing the belts (or really tightening them up) just to see if the noise changes or goes away.

Not trying to throw rose colored glasses over things, as it may still be time for a rebuild. But I've heard loose front accessories sound an awful lot like a bearing before.
Figure it's worth a few minutes of your time at this point.

As for special, I agree newer better cylinder heads, and a new EFI friendly cam, with a 114° LSA (lobe separation angle). Of course with the proper late model firing order so the computer fires the injectors at the right time.

That's all if it's a Bronco engine with the Mustang EFI. If it's the whole Mustang package then the firing order is already correct. But new heads and cam might still be in order.
Do you know if this is a MAF or Speed Density engine? Does it have a MAF sensor ahead of the throttle body?

Paul

 

[Chief Master Sergeant]

Is it a V-belt or serpentine configuration? If V-belt and maybe an old damper, try removing the belts (or really tightening them up) just to see if the noise changes or goes away.

Not trying to throw rose colored glasses over things, as it may still be time for a rebuild. But I've heard loose front accessories sound an awful lot like a bearing before.
Figure it's worth a few minutes of your time at this point.

As for special, I agree newer better cylinder heads, and a new EFI friendly cam, with a 114° LSA (lobe separation angle). Of course with the proper late model firing order so the computer fires the injectors at the right time.

That's all if it's a Bronco engine with the Mustang EFI. If it's the whole Mustang package then the firing order is already correct. But new heads and cam might still be in order.
Do you know if this is a MAF or Speed Density engine? Does it have a MAF sensor ahead of the throttle body?

Paul

It's a MAF. I think I'll look for the GT40 heads. The builder seemed to know what I might need, but thought to ask those who have been there, done that. Getting tired of not being able to drive it.

I'll try to tighten those belts this evening and see what happens.

 

[rjrobin2002]

I would go get a $200 junk yard explorer 5.0 and have it rebuilt instead of your current engine for multiple reasons s and put your efi on it. Then you can keep driving it till the rebuild is done.

Then you get a roller engine, 1 piece rear seal, and gt40 intakes and heads.

 

[Timmy390]

I would go get a $200 junk yard explorer 5.0 and have it rebuilt instead of your current engine for multiple reasons s and put your efi on it. Then you can keep driving it till the rebuild is done.

Then you get a roller engine, 1 piece rear seal, and gt40 intakes and heads.

Very true and I agree 100%

The stock 90 Stang came with E7 heads as I recall (I owned one) so it would run well with those (mine sure did) but they really responded to bumping the timing base from 10 to 14 and the addition of the GT40 stuff made them scream.

Not a fan of the HO cam in a Bronco but the roller in the Explorer engine is good. Makes some good torque

Tim

 

[DirtDonk]

Doing it that way has another advantage. Once the new engine goes in, you can sell off your original for a couple of hundred and get back some of your investment.

Paul

 

[68ford]

Considered a stroker kit? They're cheap nowadays and the 50ci all from stroke is almost always worth 75 ft lb of torque and will make torque at a lower RPM by nature.
If your engine is knocking, can only assume youll be buying pistons and investing labor dollars into turning your crank and dialing the rods in. All to end up right back where you started with the same actual parts.
Obviously your budget is what matters.

 

[Chief Master Sergeant]

I would go get a $200 junk yard explorer 5.0 and have it rebuilt instead of your current engine for multiple reasons s and put your efi on it. Then you can keep driving it till the rebuild is done.

Then you get a roller engine, 1 piece rear seal, and gt40 intakes and heads.

Worth asking the question. I'll see if there are any available locally. What years should I be looking for?

 

[68ford]

I have seen at least half a dozen dyno comparisons where the only change was from e7 heads to gt40s, while the gt40s did make about 12hp more(at higher RPM than most broncos see anyway), torque was only 3to 5 ft lb more.
If you already have comparable E7 heads, and being 1990 engine you already have a roller cam, plus will use your old injection which was recommended, it doesnt seem to make any sense to buy another engine that still needs rebuilt? Explorer 5.0 is basically the same as what you have correct?

 

[Chief Master Sergeant]

I have seen at least half a dozen dyno comparisons where the only change was from e7 heads to gt40s, while the gt40s did make about 12hp more(at higher RPM than most broncos see anyway), torque was only 3to 5 ft lb more.
If you already have comparable E7 heads, and being 1990 engine you already have a roller cam, plus will use your old injection which was recommended, it doesnt seem to make any sense to buy another engine that still needs rebuilt? Explorer 5.0 is basically the same as what you have correct?

No, this is the original motor. I just slapped the EFI stuff on it and ran it. Ran pretty good up until recently. I think I have found a good Explorer 5.0 to have rebuilt.

 

[Rustytruck]

Down the rabbit hole you go.

 

[sanndmann3]

To answer your Q in post 11, 96-01 Explorers and Mountaineers have the 5.0 as an option...

 

[Timmy390]

Down the rabbit hole you go.

Yup but I'll say that CMS already has the EFI so nothing to do there UNLESS he wants to convert to the OBDII

Few things with the explorer engine........Clutch linkage mounting boss was not cast into the roller blocks as by that time they were using hydraulic throwout bearings. All the vendors sell the part you need. Just some grinding and the part.

If you get a 97 plus, it will have P heads so you will have to use the Bronco Hut shorty headers or use the Explorer manifolds. I think I rad the Bronco manifolds work too with some grinding.

All of them will have the good roller cam which is all reusable in most cases as well as GT40 upper and lower intakes.

Lower radiator hose can be an issue. I made my own with two hoses and a connector pipe.

Tim

 

[68ford]

https://blueprintengines.com/produc...te-engine-small-block-ford-longblock-bp3472ct

any thoughts on purchasing something like this as opposed to buying a used explorer 5.0 and then spending money to rebuild it? If I'm not mistaken it has over a hundred more horsepower and quite a bit more than a hundred foot pounds of torque more than an explorer 5.0. I understand that it may cost more in the long run, but if not that much more, you will end up with a lot more engine.

 

[bulletpruf]

https://blueprintengines.com/produc...te-engine-small-block-ford-longblock-bp3472ct

any thoughts on purchasing something like this as opposed to buying a used explorer 5.0 and then spending money to rebuild it? If I'm not mistaken it has over a hundred more horsepower and quite a bit more than a hundred foot pounds of torque more than an explorer 5.0. I understand that it may cost more in the long run, but if not that much more, you will end up with a lot more engine.

You'd be better off with the Blueprint engine, in my opinion. You're getting an engine that's already been checked out, unlike what you're going to find in a junkyard. And you don't have to deal with the delays in getting parts, the machine shop, etc.

I also like the idea of a 347 -- you also get the cubes but you don't have the tall deck of the 351 to deal with.

Numbers look pretty good, too -- 380 ft/lbs is healthy.

I'm actually considering something along these lines myself, but I'd prefer aluminum heads, mainly for the weight savings. I also don't know what compatibility issues you're going to have with this engine (EFI, headers, manual trans, etc).

 

[Timmy390]

That bluePrint motor listed in the link has this in the "Notes" Will not work for factory fuel injected applications.

My guess is because of the cams 110 degree lobe separation. You would have to get the ECM reprogrammed to work properly. If thinking of going with them, call and ask questions.

Tim

 

[68ford]

That bluePrint motor listed in the link has this in the "Notes" Will not work for factory fuel injected applications.

My guess is because of the cams 110 degree lobe separation. You would have to get the ECM reprogrammed to work properly. If thinking of going with them, call and ask questions.

Tim

I'll bet you right. I'm guessing it's on a 112, doubt they would put a tight 110 cam on an engine with iron heads. But either way, tighter lobe sep will always make more torque and at lower RPM ;D