2015 GT 5.0 cylinder heads

[steveespo]

Does anyone know if the 2015 5.0 cylinder heads definitively fit on 11-14 blocks and match up to our intakes and exhaust? I really think they do but was hoping someone has inside information. Since valve sizes and higher lift cam are the same or similar to the Boss heads and the ports are supposedly cast like the Boss CNC shape I can outfit my future Aluminator short block for about $1000 less than Boss heads and still make the same power. If any has done it or has info on this please share.
Steve

 

[ArizonaBOSS]

Does anyone know if the 2015 5.0 cylinder heads definitively fit on 11-14 blocks and match up to our intakes and exhaust? I really think they do but was hoping someone has inside information. Since valve sizes and higher lift cam are the same or similar to the Boss heads and the ports are supposedly cast like the Boss CNC shape I can outfit my future Aluminator short block for about $1000 less than Boss heads and still make the same power. If any has done it or has info on this please share.
Steve

Not 100% sure on this but I did ask around about this before. The oil/coolant passages might not mate up, IIRC. In for very specific answer.

 

[VoodooBoss]

Call Ford Racing and ask. If they don't know call Patrick at Watson Racing. They've had a few 2015 engines they've been testing.

 

[Grant 302]

Not 100% sure on this but I did ask around about this before. The oil/coolant passages might not mate up, IIRC. In for very specific answer.

I hope that's not the case! Also in for any answers.

 

[Boss0144]

They bolt on ok. The VCT is different though. There is a restrictor in the oil passage in the head that wasn't there on 2011-2014. The new VCT system needs full oil pressure and flow. On 2011-2014 the flow is restricted in the head gasket. The restriction is removed in the new head gaskets.

The valve train is not designed for the same speed capability as the boss stuff.

Also, a Boss intake will bolt right on, but a 2011-2014 GT intake requires modification to clear the new intake flange.




Sent from my iPhone using Tapatalk

 

[VoodooBoss]

Should we use the new head gaskets on our cars?

 

[steveespo]

Boss0144
Why do you think the valvetrain is not as RPM capable as the Boss setup? The info on the '15 engines was that the valvesprings were uprated like the Boss. Other parts such as the rocker arms and lash adjusters were no different from Coyote engines. Doesn't matter as I would use Trick Flow springs anyway. I messaged Dean Martin and he likes this swap and doesn't think there are any major hiccups.
I guess using the new head gaskets would be the best course. Any other detail info you have would be appreciated.
Steve

 

[ArizonaBOSS]

This is all better than expected

 

[DGRacing]

Are there any special ECU requirements with the new engine parts mixed with the old? i.e. will the old ECU's work with them?

 

[Hermes]

Should we use the new head gaskets on our cars?

I wouldn't mess around with head gaskets or ECU swaps unless you're going to change everything [heads, VCT, and possibly oil pump]. Like BOSS0144 said, the VCTs are different. I understand the new VCTs use an intermediate lock pin on the intake phasers that allow cam retard as well as advance from a default position that allows the car to start easily. Our BOSS engines don't have that. Removing the oil restriction was likely necessary to allow the lock pin in the phaser to retract quickly. Its likely that either a larger capacity oil pump or other changes were made to the oil circuit to ensure pressure throughout the engine.

 

[steveespo]

Not looking to use '15 phasers just the castings for valve size and port shape. Balance of hardware would be '11-'14 spec with cams from Comp or Ford Racing. If the timing gear fits then I will proceed. More research will be done.
Steve

 

[302 Hi Pro]

Not looking to use '15 phasers just the castings for valve size and port shape. Balance of hardware would be '11-'14 spec with cams from Comp or Ford Racing. If the timing gear fits then I will proceed. More research will be done.
Steve

Then I would think you would use the 11-14 style head gasket to keep same oil supply to your cams and valve gear.

Dave
302 HP

 

[steveespo]

Then I would think you would use the 11-14 style head gasket to keep same oil supply to your cams and valve gear.

Dave
302 HP

If understand Boss0144 post correctly he states there is an oil flow restrictor built into the '15 heads that wasn't in the earlier heads, therefore the late gasket should be used with late heads and early gasket with early heads to maintain oil flow. If you use an early gasket with the late heads it will be double restricted and may not have sufficient oil flow for either style phaser.

 

[steveespo]

Update
Just bought a set of brand new bare Boss 302 heads on eBay for $1052 shipped. OEM Ford valves, springs, retainers, seals and keepers, plus the 10 cup plugs add $764 to that cost to make them fully dressed as you would get from Ford Racing. Total $1816, best assembled set cost I've found is $2329, saving is $513. Best price I could work up on the '15 heads dressed was $1903, mostly because of a $250 per head core charge. Also appears the '15 valves are not the special lightweight valves used in the Boss heads.
Steve

 

[302 Hi Pro]

If understand Boss0144 post correctly he states there is an oil flow restrictor built into the '15 heads that wasn't in the earlier heads, therefore the late gasket should be used with late heads and early gasket with early heads to maintain oil flow. If you use an early gasket with the late heads it will be double restricted and may not have sufficient oil flow for either style phaser.

Thanks Steve, and Yes, I missed that. The oil restricter moves from the 2011-14 head gasket to the 2015 cylinder head, so you must use the non-restricted 2015 head gasket.

Conversely, using the old gskt with the new head would net 2 oil restrictions, one in gskt and one in cylinder head.

Second item: Now that we have original Boss engines being torn down, is anyone seeing signs of cylinder head coolant flow problems as first reported by some back in 2011/12? They were also trying to sell a coolant hose bridge for the rear of our cylinder heads. I'm hoping this is a non-issue with our engines.

Thanks,
Dave
302 HP

 

[ArizonaBOSS]

Snake oil on that coolant bridge. @ilesjohn can comment more on that if he chooses.

 

[302 Hi Pro]

Snake oil on that coolant bridge. @ilesjohn can comment more on that if he chooses.

That is very good news. Thanks for the update.
Dave