GT350 Engine Refresh Time!

[bauern]

Beefing up the block with sleeves to keep its rigidty when it gets really hot

Just for clarification: these will be wet sleeves?

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[honeybadger]

Just for clarification: these will be wet sleeves?

They'll be dry sleeves.

 

[Bcobb85]

The pistons and rings have been revised for tighter clearances for 18+ engines. The factory specs (tolerances) for piston to cylinder wall clearance minimums are now less than half of what they were in earlier engines..
The new OEM pistons are much more expensive too. Like $160+ each now. There is a new chain tension revision also due out this spring. I just noticed the new part number is JL3Z -6L266-B. you might want to check into the revised pistons and rings if you were experiencing "excessive" oil consumption.

***Disclaimer: I am a total noob when it comes to the specifics of engine building so please forgive my question if it is a dumb one.***

Aside from reduced oil consumption and piston rattle at cold temps, are there any other benefits from the tighter clearances on the revised motors? Increase in power perhaps?

Also, Are there any downsides?

It seems that some of the revisions that the Voodoo has received have been more focused on reducing customer complaints than improving the design/performance of the motor. For example, dealers/customers were having issues following the manual with tightening the original oil filters properly, so Ford revised the filter to make it more idiot proof and reduce the likelyhood of incorrect installation. With the same logic, could the revised piston/cylinder wall clearances be more a result of the oil consumption/piston rattle complaints and less an improvement in design/performance of the motor itself?

 

[honeybadger]

***Disclaimer: I am a total noob when it comes to the specifics of engine building so please forgive my question if it is a dumb one.***

Aside from reduced oil consumption and piston rattle at cold temps, are there any other benefits from the tighter clearances on the revised motors? Increase in power perhaps?

Also, Are there any downsides?

It seems that some of the revisions that the Voodoo has received have been more focused on reducing customer complaints than improving the design/performance of the motor. For example, dealers/customers were having issues following the manual with tightening the original oil filters properly, so Ford revised the filter to make it more idiot proof and reduce the likelyhood of incorrect installation. With the same logic, could the revised piston/cylinder wall clearances be more a result of the oil consumption/piston rattle complaints and less an improvement in design/performance of the motor itself?

I agree with your assessment based on my own understanding. Performance/reliability could be improved with better balancing of the rotating assembly and more accurate engine blueprinting since they'd reduce friction (and friction creates heat -->which increases stress). However, my understanding of the revisions is that they've addressed piston slap and oil consumption. While both aren't necessarily "harmless," both are common occurrence in high performance engines with forged internals.

That said - it's probably still a good thing they're making the revisions. It seems the GT350 might have came with a few too many quirks for their average buyer

 

[Bcobb85]

I agree with your assessment based on my own understanding. Performance/relaiblity could be improved with better rotating assembly balancing and more accurate engine blueprinting since they'd reduce friction --> which creates heat -->which increases stress. However, my understanding of the revisions is that they've address piston slap and oil consumption. While both aren't necessarily "harmless," both are common occurrence in high performance engines with forged internals.

That said - it's probably still a good thing they're making the revisions. It seems the GT350 might have came with a few too many quirks for their average buyer

Yea, thats kind of what I am getting at. I always thought the advantage of the looser tolerances was an increase in performance (less friction) with the downside being oil consumption and piston slap. So I'm wondering if there is a downside to the tighter tolerances which get rid of the oil consumption and piston slap. Increase in friction?

It definitely feels like they are catering more towards the average Joe who wants a track car but doesn't want to worry about the maintenance of one (checking torque specs, adding oil, etc.). Case in point; for 2019 this "track car for the road" has ditched the Base R trim (radio/AC delete) and is now offering a B&O sound system and cobra snake puddle lamps, lol.

 

[Epiphany]

The radio delete getting axed was the result of new federal law requiring backup cameras.

 

[AdamIsAdam]

I believe piston slap won't change with different piston rings. I thought that's from the piston being forged aluminum. But tighter tolerances I think will reduce oil consumption but sacrifice a small amount of HP.

As an FYI, my `99 911 manual states almost all of the same things/issues: forged pistons, tolerances that can cause high oil consumption (up to 600 miles per quart is acceptable and even expected with track / high speed use). So 20 years later, it's the same thing. Tried and true tricks of engine building, I guess.

 

[AceOne]

I agree with your assessment based on my own understanding. Performance/reliability could be improved with better balancing of the rotating assembly and more accurate engine blueprinting since they'd reduce friction (and friction creates heat -->which increases stress). However, my understanding of the revisions is that they've addressed piston slap and oil consumption. While both aren't necessarily "harmless," both are common occurrence in high performance engines with forged internals.

That said - it's probably still a good thing they're making the revisions. It seems the GT 350 might have came with a few too many quirks for their average buyer

You summed it up well imo. My understanding is the piston tolerances and rings on the original motor were a bit loose to reduce friction and aid in HP numbers. I think with tolerance stack it made too many have oil control issues and therefore, very unhappy customers. This was an amazing engine when introduced based on it being a mass produced engine producing over 101 hp per liter and a 8250 rev limit. Pretty impressive to me and I'm sure the engines need some revisions as usage shows where improvements can be made. I'm sure Ford is focused on durability and hope to reduce engine failure for what ever reasons so I'm sure the revisions were more focused on the durability as opposed to trying to up the HP. HP power improvements are handled more in Ford Performance division.

I must say mine really puts a smile on my face every time I mash the go pedal now. 530 whp and 400+ torque from 3000 rpm now...this thing just moves out like a supercharged car and pulls like a freight train all the way past 8K.

 

[AceOne]

Thanks. I've used the Coyote covers in the past as that's what's listed in the online catalogs even Fordparts regardless of "R" or not. Did not know of the GR3Z number. Drivers side is the last resort for blowby, I'd like to see your modification.

I just got the GR3Z - A number recently. I almost modified my existing cover after my third "burp". I did find a very possible correlation to oil level. Both of my first "burbs" happened when the oil level was just a bit over the mark. Each time I drained a little form the engine in between sessions...no more burp. drained less that 1/2 quart each time .. The older coyote engine we could run 1/2 high for racing and extra capacity when on banked tracks. I don't do that on this voodoo engine now. It did it once again at OUSCI in Vegas when the oil was right at the mark. I have also switched to the Radium catch can on DR side now and hope that helps. I will definitely study the baffle and oil drain locations on the heads as I assemble this motor to look for way to improve it.

 

[honeybadger]

I just got the GR3Z - A number recently. I almost modified my existing cover after my third "burp". I did find a very possible correlation to oil level. Both of my first "burbs" happened when the oil level was just a bit over the mark. Each time I drained a little form the engine in between sessions...no more burp. drained less that 1/2 quart each time .. The older coyote engine we could run 1/2 high for racing and extra capacity when on banked tracks. I don't do that on this voodoo engine now. It did it once again at OUSCI in Vegas when the oil was right at the mark. I have also switched to the Radium catch can on DR side now and hope that helps. I will definitely study the baffle and oil drain locations on the heads as I assemble this motor to look for way to improve it.

What do you mean oil burp? This is new to me!

 

[AceOne]

What do you mean oil burp? This is new to me!

Under high load and carousel turns some cars have pushed oil out the PVC line past catch cans and blew oil out the air filter. It makes a mess...I even had one car spin out behind me after mine burped once. It just spit it out . soaks the air filter and blows ingested oil out the tail pipe...hence the spinout of the Camaro behind me....it was a Camaro so no harm, no foul! I did apologize to him afterward though and was glad he was okay and only looped it and kept if on track.

 

[lgvenable]

Kevin loved the thread, used it to help understand the coyotes internals, since I'm new to this engine.

I did have a coupe of questions, based on work, as I didn't see some things I did in my NA build in I had done on an LS7 for durability and power... didn't notice if you chose special valve guides? In my build mold-star 90's were used, they're from F1, and the shop that did my heads made two big changes 1st- stud mounted roller rockers to make sure there was absolutely zero side loading on the valve stems..major issue on about 4% of LS7's in the early days of that engine; combined with the MS90 guides Kohle's claim was 100,000 street miles w/o any issues in the heads. The early LS7's could show issues at 18,000 miles on the street. When that work was done, I debated building a track LS7, but didn't; rather based the build to be used mainly on the street, so that I had minimal bottom end changes. However if I had gone for a track build I would have used piston squirters too as well as tearing into the short block like you have., I didn't see that you did that, or are you waiting for the next refresh - or did I miss them?
Great build! ..Larry

 

[Freedom]

very niceeee

 

[Spart]

Subbed. Thanks for all the great info!

While I have no intentions of rebuilding my purely street-driven car that only sees about 4000 miles per year, if it becomes my forever-car I’m staring down the barrel of this at some point.

 

[Bcobb85]

But tighter tolerances I think will reduce oil consumption but sacrifice a small amount of HP.

If that is the case then I will happily take the original design that eats a little oil. Mine has been fairly consistent at 1 quart every 2k miles which doesn’t bother me as long as it isn’t shortening the life of the motor. I purchased the car expecting to have to check and top off oil on occasion so this didn’t come as a shock.

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