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i pulled the f150 pump gear out and they are a dead ringer for the 3v pump pic posted. looking at the gears compared to the mod motor it looks like the coyote has the same diameter but smaller flats.
 

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I knew I had them, just couldn't remember where I put them. Dave (dhenderson) already documented this for us. Here is the image of his drawing;

Shaft 0.jpg

The width across the Coyote oil pump drive flats is 1.545 inches and the width across the 4.6 oil pump drive flats is 1.415 inches which means either massaging the Coyote crank to use a Modmotor oil pump or massaging the Coyote pump to fit/work in the Modmotor.

There is also about a 0.090" longitudinal registration difference in where the lower crank sprocket registers on the Coyote crank snout.

Ed
 

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When MMR makes the 4.75 Stroker (Coyote crank, 4.6 block), they machine the oil pump to accommodate the crank snout.
 

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When MMR makes the 4.75 Stroker (Coyote crank, 4.6 block), they machine the oil pump to accommodate the crank snout.
The question probably comes down to which method is better. If you are replacing the gears with billet ones, having them made to work may be the way to go. I think there is still some machining required of the flats to make that work. You can see Dave's comments about that in my thread i think. (Teksid Build) Post #73
 

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The question probably comes down to which method is better. If you are replacing the gears with billet ones, having them made to work may be the way to go. I think there is still some machining required of the flats to make that work. You can see Dave's comments about that in my thread i think. (Teksid Build) Post #73
That is the pregnant question, Herb. I think you want to be able to buy a standard oil pump and lower timing gear for replacement purposes which would argue the Modmotor 3V pump and machine the Coyote crank snout oil pump drive flats, journal diameter and timing gear register to standard Modmotor dimensions. If that is the approach then the issue of driving the oil pump off a journal that has been cut below its very shallow protective nitrided surface becomes a question that needs to be addressed. i.e. can it be done w/o premature journal wear on the crank?

If the answer is no, then the Coyote pump with an unmodified oil pump drive journal on the crank snout becomes the prudent way to go and modify the Coyote pump housing to work so it clears the modmotors primary cam drive chains and allows proper placement of the chain tensioner. Both operations are relatively straightforward so it does not appear to be a lot of expense. Whenever we do a rebuild we typically use a billet pump gears to replace the OEM powdered metal pieces and reuse the pump housing unless we have found that it has been somehow damaged. There is of course still the 0.090" difference in location of the lower timing sprocket register but that is an easy fix in a lathe and the nitrided surface is not a concern for that operation.

I am not certain yet which path is better but I am developing a bias for the modified Coyote pump.

Ed
 

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Discussion Starter · #27 ·
When MMR makes the 4.75 Stroker (Coyote crank, 4.6 block), they machine the oil pump to accommodate the crank snout.
They must machine the crank as the mod pump I have here came off of a MMR strocker shortblock. It fits the cobra crank.

I did confirm the measurements listed above. I get the same within .002.

I am thinking if I can get a 3V pump and cut it deeper to fit the Coyote gears making using the crank easier.
 

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They must machine the crank as the mod pump I have here came off of a MMR strocker shortblock. It fits the cobra crank.

I did confirm the measurements listed above. I get the same within .002.

I am thinking if I can get a 3V pump and cut it deeper to fit the Coyote gears making using the crank easier.
Just ask them to find out for sure (They always want to know how they can help), although I doubt Tim is mistaken. Don't discount the idea that there may be several iterations of the MMR slop filling the trough.
 

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They must machine the crank as the mod pump I have here came off of a MMR strocker shortblock. It fits the cobra crank.

I did confirm the measurements listed above. I get the same within .002.

I am thinking if I can get a 3V pump and cut it deeper to fit the Coyote gears making using the crank easier.
i measured used truck (2014 f150) gears they are the same as the 3v dimensions you posted earlier, assuming they have the same center to center offset they should bolt right into a 3v pump. tho only other gotcha i can think ov is the .079 difference in timing gear placemnt.
 

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Just ask them to find out for sure (They always want to know how they can help), although I doubt Tim is mistaken. Don't discount the idea that there may be several iterations of the MMR slop filling the trough.
I sent MMR an email some time ago asking if it was in fact the coyote crank and specifics about what they do to the crank to make it work and got crickets.
 

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I think the goal we should try to achieve, if possible, is to use the least amount of custom parts and machine work to make the crank operational in a Modmotor. We are trying to take advantage of Ford's low pricing on this piece and significant custom work to fit it all together defeats the original reason we went this path.

My suspicion is the Coyote gerotor set is a wider faced gear set than the 3V set and I thought someone said a larger diameter gear set also. If that is true then the Coyote pump housing clearancing for the chain and a haircut where the tensioner bolts up would be the short way home. We are already going to go billet gears so, we buy those as standard Coyote pieces from Travis — FWIW I strongly suspect his are the best choice out there. Once we put them into a modified Coyote pump housing we are basically done other than a 0.090" haircut on the lower sprocket crank register.

Ed
 

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I am still wondering if we can not just get Travis to make gears that will match the coyote crank on the ID and the 3V pump for the OD? Then no modes to the housing would be required? Are you thinking that the Coyote Truck gears will fit in the 3V housing? I would think that OD would be different, unless Ford took the 3V pump and reworked the ID to fit the coyote? Lots of conjecture there on my part!

Looking at Dave's drawings of the crank, if we did get Travis to make those gears, would they locate in the same spot on the crank as the stock 3V pump on the stock mod crank? Not having the Coyote crank and gear, having a hard time seeing that.
 

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Discussion Starter · #35 ·
You basically nailed the key.
I spoke with Travis and that very idea is coming soon. My plan is to make the spacers with the front timing gear that is cut. Then I will put a whole kit together so that all the end user will need is to pick up a crank.

I have a few more concerns. If I make a spacer for the damper bolt will the bolt interfere with the lower crank drive for the blower?
Also as far as the crank timing chain sprocket. The one I have here from MMR is cut .160 deep. While all our measurements show .090 difference. There must be a reason for this?
 

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You basically nailed the key.
I spoke with Travis and that very idea is coming soon. My plan is to make the spacers with the front timing gear that is cut. Then I will put a whole kit together so that all the end user will need is to pick up a crank.

I have a few more concerns. If I make a spacer for the damper bolt will the bolt interfere with the lower crank drive for the blower?
Also as far as the crank timing chain sprocket. The one I have here from MMR is cut .160 deep. While all our measurements show .090 difference. There must be a reason for this?
Count me in!
On the blower drive, i am using a METCO set up. It should not interfere in my case. 010.jpg
 

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I measured the relief on the back of an OEM Modmotor sprocket James. The dimension is 0.053". Dave's drawings show a 0.079" increase in register height on the Coyote crank.

I have positioned Ford's snout drawings for a Coyote and a 4.6 side by side in the pic below. Ford uses metric dimensions so all numbers are metric.

Comparisons.jpg

These are just the snout portions of the individual prints. Ford's datum for the cranks is somewhere near the rear flange of the crank and could be different for the two cranks. To remove the differences we can use a known starting point that should reproduce across both engines. A good reference point would be the inside edge of #1 main journal. If we use this as a reference then we can measure the distance to the crank snout timing rear register and compare it crank to crank.

The math for the Modmotor crank looks like this, #1 main journal inside edge location off the Ford print is 422.0 mm +/- 0.2mm. The timing gear sprocket location is 478.29mm +/- 0.1mm. Lets use the on center measurements and we find the timing gear register is 478.29 mm - 422.0 mm or 56.29 mm forward of the rear most point of #1 main journal.

Using the same math on the Coyote crank, the #1 main journal is located at 422.08 mm +/- 0.2 mm from its datum line. The Coyote timing gear sprocket location is 483.24 mm +/- 0.1mm. Again lets use the on center measurements and we find the timing gear register is 482.24 mm - 422.08 mm or 61.16 mm forward of the rear most point of #1 main journal.

The difference in these two measurements should be the offset difference. So we subtract 56.29 from 61.16 and we get 4.87 mm or 0.192" that the Coyote register is too far forward.

These numbers assume the same recess on the backside of the lower timing sprocket for both the Coyote and the Modmotor crank. I have measured the Modmotor lower timing sprocket recess at 0.053" What we need now is for someone to be able to measure the recess on the backside of the Coyote sprocket for comparison.

Even without the Coyote sprocket measurement we can say with certainty that the register for this sprocket on the Modmotor crank is 0.192" farther back than it is on the Coyote crank. If we want to run an unmodified lower sprocket than we have to cut back the crank register for the lower timing sprocket by 0.192" on the Coyote crank to work.

Why 0.192" ? Don't forget the crank trigger reluctor wheel is no longer on the front of the Coyote crank. That reluctor wheel measures 0.103" thick. When you take the additional 0.103" for the reluctor wheel into consideration the offset becomes 0.089". This dimension is within 0.010" of the dimension Dave pulled off the two cranks when he took his measurements.

Couple of closing thoughts;

◉ We need to remember we need to properly position the reluctor wheel,

◉ We want the primary drive chain sprockets to be as closely aligned as possible,

◉ When you look at the snout prints the indexing key for the Modmotor crank does not appear on the coyote crank,
- this needs to be checked to insure correct cam phasing,

◉ While all the other mods are being done, you should have the crank cut for a square key, the woodruff key belongs on a refrigerator compressor,

◉ My suggestion would be to modify the Coyote crank snout so you can purchase off the shelf timing components rather than using one off custom pieces,

◉ If Travis makes a billet gerotor set for a 3V pump with a Coyote compatible inner rotor this will be one hot item,

Lastly, notice how far into the crank snout the Coyote damper bolt goes. It almost reaches the oil pump drive journal. If you continue to take the drilling to the #1 main bearing's center point (or deeper to the counter weight) you will duplicate the ModFords crank snout stud modification we came up with several years ago. This would be a very big step in the right direction and a very big benefit for the strength and longevity of the crank - and this is the correct time to do the mod before you put the new shaft into your engine.

Ed
 

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Lastly, notice how far into the crank snout the Coyote damper bolt goes. It almost reaches the oil pump drive journal. If you continue to take the drilling to the #1 main bearing's center point (or deeper to the counter weight) you will duplicate the ModFords crank snout stud modification we came up with several years ago.
Ed
Ed, do you have a link to that Mod?
 

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◉ If Travis makes a billet gerotor set for a 3V pump with a Coyote compatible inner rotor this will be one hot item,
i don't know about boundary but tss makes this gear https://www.lmengines.com/products/b...ump-gears.html
the mustang and f150 coyote have different pumps. i measured a f150 pump gearset it is .510 wide, 3.50 od and 1.7 id, other than the flats that is identical to the 3v pump.

i have a used f150 pump and a new 3v pump i was going to play with today but i ended up needing to rebuild a c4 and install it before monday.
if james could measure the distance from the pump mounting flange to the front of the #1 crank journal on both the coyote and mod crank, it can make the offsets of the crank snout dimensions absolute( or close to it)
then measure the distance from pump mount flange to back side of gear on both his pumps that would help. when i am done with this damd unexpected tranny deal i can measure my pumps( 3v and f150 coyote
 
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