Suggestions on 331 explorer build

[Stage 2 Dan]

Hello everyone
I have a 2wd 1999 ranger with a 2000 200K mile explorer driveline in. The vehicle is a blast to drive however I would like to pump it up some more by building a mild 331 and swapping it in.
I was planning on a 9-1 331 with a set of bowl blended GTP`s with roller rockers.I was leaning towards a stock 5.0 HO camshaft because I have to pass emissions. I would like to go with an aftermarket cam but from what i have heard on the form that this could be a real pain to have to deal with and pass the smog test.
I realize that I would have to get a handheld tuner and have a specific tune possibly created. I was thinking about 24# injectors and a matching mass air. I have a set of FMS headers that are going on with the swap.

My concerns are how to deal with the 28 oz balancer balancer and the explorer`s distributorless ignition, swapping out injectors and a mass air. Also who should i go with for a tuner? I have heard horror stories since the EPA started blasting the aftermarket tuners.
I would like to be in the 300-350 hp area and be able to pass the emission test. Is this a obtainable goal, or am I off my rocker?
Thank you.
Dan.

 

[CDW6212R]

Hi Dan, your emissions process will be your biggest hurdle. I believe they will require the engine to pass the stock levels of a 2000 302 engine, not a higher percentage due to the larger engine. So you might first find out what those stock limits are, and how your stock engine compared in the last testing. I'd call an emissions place there and ask for guidance on that. You'll have to maintain EGR and unless in a state like stupid CA, the intake and heads could change without failing testing by visual alone.

You won't hit power levels like any non-Explorer chassis 302, like Mustangs etc. The exhaust limits airflow radically, stock is under 50% of common stock Mustang flow. The FMS or TM headers don't gain much to approach Mustang headers, a little but not much really. So the size you build the engine should consider the limitations, and not let you go too wild with heads or rpm etc.

If you stick with GT40P level head flow, and 5000rpm or so, you can do a lot for lower rpm power. If the emissions have a chance of passing with a good stroker, a 347 would net the best power curve. Basically the power curve will be moved down 302/347 exactly, what is that, 15% down lower. A 347 does not use more oil than a 332, or wear out pistons/cylinders faster. Choose one based on emissions expectations. If it seems unlikely to pass with the bigger engine, don't do the 3.4" stroke, stick with 3.25" or stock 3.0" cranks.

The 3.25" stroke crank adds exactly 25 cubic inches, the 3.40" stroke adds exactly 40 cubic inches, and each .030 overbore adds right at 5 cubic inches. So a .030 over 3.25" crank nets 332 cubic inches, not 331(that's a myth).

You will need a tuner/flasher, so why not raise the compression to gain power, that's easy power, but needs a specific cam to work with it. I'd bite the bullet and get a custom cam, made for the whole combination. That would have the best chance to pass emissions.

Stock GT40 level heads only flow around 200cfm, porting can get them up to 225-235 for a bunch of money. Aftermarket heads usually begin at close to 250cfm, the $1500 heads are more around 270cfm, and they go up in flow and price after that.

There is one 28oz balancer source for the Explorer, a re-balanced stock piece for I think about $200.

Price out the cost of machine work and a stroker kit, you can easily spend $3000. The tuner and custom cam, injectors etc, that's extra items outside of the main engine. Consider all of that, and try to set a budget. I'd stick with the stock heads if possible depending on the budget, and that means use the stock pedestal rockers.

Roller rockers on studs are unreliable, fine for rare use street/strip cars, but for a daily driver it's a big risk. Stock pedestal rockers are very reliable, and roller rockers only gain a few HP above them. If you use stock type heads, stick with those rockers if they are in great shape. They will also be quieter.

I'm going to build a 306 late this year, with knock-off GT40X heads(maybe 235cfm if I'm lucky). Those head like most have no pedestals, require stud or shaft rockers. For a daily use truck, my 99, I'll buy LGM rockers from FTI(as in Ed Curtis custom cams); LGM Shaft Rockers - SBF inline valve heads
Those shaft rockers will be very reliable, but it is an extra $500+ versus studs and roller rockers plus guide plates.

Think through the many choices. A non stock engine that has to have PCM tuning, you can easily integrate a custom cam, any injectors, any MAF, any compression, any heads, and any intake. You shouldn't alter any of that and expect to use stock programming. Plan ahead, add up the costs, it can be high.

 

[Stage 2 Dan]

Hi Dan, your emissions process will be your biggest hurdle. I believe they will require the engine to pass the stock levels of a 2000 302 engine, not a higher percentage due to the larger engine. So you might first find out what those stock limits are, and how your stock engine compared in the last testing. I'd call an emissions place there and ask for guidance on that. You'll have to maintain EGR and unless in a state like stupid CA, the intake and heads could change without failing testing by visual alone.

You won't hit power levels like any non-Explorer chassis 302, like Mustangs etc. The exhaust limits airflow radically, stock is under 50% of common stock Mustang flow. The FMS or TM headers don't gain much to approach Mustang headers, a little but not much really. So the size you build the engine should consider the limitations, and not let you go too wild with heads or rpm etc.

If you stick with GT40P level head flow, and 5000rpm or so, you can do a lot for lower rpm power. If the emissions have a chance of passing with a good stroker, a 347 would net the best power curve. Basically the power curve will be moved down 302/347 exactly, what is that, 15% down lower. A 347 does not use more oil than a 332, or wear out pistons/cylinders faster. Choose one based on emissions expectations. If it seems unlikely to pass with the bigger engine, don't do the 3.4" stroke, stick with 3.25" or stock 3.0" cranks.

The 3.25" stroke crank adds exactly 25 cubic inches, the 3.40" stroke adds exactly 40 cubic inches, and each .030 overbore adds right at 5 cubic inches. So a .030 over 3.25" crank nets 332 cubic inches, not 331(that's a myth).

You will need a tuner/flasher, so why not raise the compression to gain power, that's easy power, but needs a specific cam to work with it. I'd bite the bullet and get a custom cam, made for the whole combination. That would have the best chance to pass emissions.

Stock GT40 level heads only flow around 200cfm, porting can get them up to 225-235 for a bunch of money. Aftermarket heads usually begin at close to 250cfm, the $1500 heads are more around 270cfm, and they go up in flow and price after that.

There is one 28oz balancer source for the Explorer, a re-balanced stock piece for I think about $200.

Price out the cost of machine work and a stroker kit, you can easily spend $3000. The tuner and custom cam, injectors etc, that's extra items outside of the main engine. Consider all of that, and try to set a budget. I'd stick with the stock heads if possible depending on the budget, and that means use the stock pedestal rockers.

Roller rockers on studs are unreliable, fine for rare use street/strip cars, but for a daily driver it's a big risk. Stock pedestal rockers are very reliable, and roller rockers only gain a few HP above them. If you use stock type heads, stick with those rockers if they are in great shape. They will also be quieter.

I'm going to build a 306 late this year, with knock-off GT40X heads(maybe 235cfm if I'm lucky). Those head like most have no pedestals, require stud or shaft rockers. For a daily use truck, my 99, I'll buy LGM rockers from FTI(as in Ed Curtis custom cams); LGM Shaft Rockers - SBF inline valve heads
Those shaft rockers will be very reliable, but it is an extra $500+ versus studs and roller rockers plus guide plates.

Think through the many choices. A non stock engine that has to have PCM tuning, you can easily integrate a custom cam, any injectors, any MAF, any compression, any heads, and any intake. You shouldn't alter any of that and expect to use stock programming. Plan ahead, add up the costs, it can be high.

 

[Stage 2 Dan]

Thanks Don,
You given me some really good food for thought. My concern was that higher compression even with a operational EGR system would equal higher HC levels. I had thought that the added cubes wouldn't be an issue as long as the a/f ratio stayed under the thresholds.
I live in n/w Indiana and we have the basic obd2 plug in and pass or fail emission testing.
I had a bet with my father that the truck would pass, he claimed it wouldn`t. (he paid up)
I told him the testing equipment doesn't know that there is an explorer engine, computer, and vats system in a ranger body. As long as everything is in fine working order were golden. (I realize that this wouldn't work in the peoples state of California.)

So basically if the OBD system is not setting and codes, and the HC CO and other gases are under the thresholds that the EPA set i should be good to go.

I will source the EPA limits and further investigate before i jump in to something.
Do you have a link for the vendor for the 28 oz balancer?

Thanks again..
Dan White.

 

[CDW6212R]

...
I will source the EPA limits and further investigate before i jump in to something.
Do you have a link for the vendor for the 28 oz balancer?

Thanks again..
Dan White.

That is the best place to start. It sounds like you passed by being under the 4.0 engine limits, which says good things about the 5.0 OBDII system. But the size of the engine directly affects the amount of material produced in the exhaust. Also ask how it works given a different engine, it sounds like it will be legal, but you hope that it will use a higher limit to test by, for the 25% larger 5.0 engine. If they do that, then you will have a larger margin of pass/fail to limit the engine.

Given that, a 347 might pass with good tuning etc. I think a compression of around 9.5:1 should be no trouble to tune for on regular fuel, that's about what I'm aiming for. I'll ask my cam designer to set that compression, there are a few pistons that will let me adjust that a little up or down.

Search here for the other 347 Explorers, I think they all have that balancer except one. Tim has one I had made, and it's also a stock Ford balancer with the rpm limitations. Keep the rpm's down with the OEM type, the two piece units do great in stock usage, for 10-20 years. But the outer part can separate, and there isn't a better option yet. I used a stock old Ford SBF balancer to have a trigger wheel attached to. I didn't at that time see anything aftermarket that could accept the trigger wheel. I plan to look harder soon, hoping to find an SFI balancer or just made stronger unit.

 

[boominXplorer]

Damper dudes is who has the 28oz stock balancer. I have it on my 351w efi shop truck but have not had a chance to fire it up yet.

 

[CDW6212R]

Here's a link to the 28oz balancer, from Damper Dudes;
DamperDudes.net (Americas Largest supplier of harmonic balancers)