Over the last few months we have been getting many calls in regards to what is required to install GT350 Heads onto the 11-16 Blocks so we figured we would share some information to help everyone within the community.
In order to understand what is needed you must understand the heads themselves. The Valvetrain geometry has changed slightly (Valves have been spread apart slightly), this however does not prevent the heads from being used with the earlier camshaft spacing since the folllower wheel or Rocker arm wheel is still 100% in contact with the 11-16 Style camshaft lobes. Now for the first problem. In an effort to reduce weight (among other things) the base circle of the GT350 camshafts were reduced, since the lifter bore locations were relatively unchanged a new roller rocker was required to fill the gap of the new smaller diameter base circle of the cam, the rockers also feature a different diameter wheel and thinner wheel to reduce friction. Ford Simply moved the centerline axis of the wheel to take up the gap caused by the new smaller base circle.
Many of you may be asking what this means for you. Basically if you want to run your existing stock or aftermarket 11-16 cams it requires the use of a Modified rocker arm (now available from MMR), the rocker arm has been clearanced to mimic the GT350 rocker arms because the camshaft will actually touch the rocker arm due to the extended valve heights of the GT350 head. Many of you may be asking "why cant I just use a GT350 rocker arm?" . The answer is that the GT350 rocker arm is not compatible with the base circle of the 11-16 cams and will hold the valve open due to its relocated wheel.
Other information you may need:
Head gaskets - You need to use 2015+ head gaskets due to the oil restrictor, GT350 gaskets can also be used but only suggested on a 3.700" bore
Bore Size - Yes, the valves do open and have adequate clearance for the std 3.630 2011-2016 Bore size
Valve Springs - The factory Valve springs have approx 60lbs of seat pressure, if your combination requires an upgrade these heads require a custom valve spring and retainer (due to the new valve length) MMR has them in stock with 2 options, see below
Camshafts - When using the MMR modified rocker arms any 2011-2016 Camshaft can be used
Other Options - Ford will be releasing custom cams later this month, many people think they are GT350 cams but they are not, they are cams made for Ford with GT350 specs but with the std 2011-2016 Firing order, they also require the 2015+ Timing chain and phaser kit (also now called the Gen2). These cams retail from MMR for $1399 but also require the GT350 rockers since these cams use a small base circle like the GT350 production cams.
Below is a picture of the GT350 heads using a 11-16 Camshaft and stock 11-16 Rocker arm, you can see it does not have adequate clearance between the rocker and the cam lobe.
Shown below is the modified Rocker from MMR, minimal material is removed in the CNC machine and this modification provides proper clearance.
A shot of the GT350 cylinder heads
Parts needed (we will update this list with links to the website shortly):
If you want to run your 11-16 Cams you will need:
MMR Modified Rocker arms - http://www.modularmotorsportsracing...ge=product_info&cPath=4_30_35&products_id=885
If your cams require upgraded valve springs you will need: http://www.modularmotorsportsracing...ge=product_info&cPath=4_30_35&products_id=850
2015-2016 Head Gaskets
If you want to run the new Ford Racing Cams Cams you will need:
The Ford Racing 5.2 Cams http://www.modularmotorsportsracing...page=product_info&cPath=26_27&products_id=893
2015-2016 Head gaskets
GT350 Rocker Arms
2015 + Timing Chain Kit http://www.modularmotorsportsracing...page=product_info&cPath=28_29&products_id=820
Any questions, feel free to ask anytime in this thread.
www.modularmotorsportsracing.com
In order to understand what is needed you must understand the heads themselves. The Valvetrain geometry has changed slightly (Valves have been spread apart slightly), this however does not prevent the heads from being used with the earlier camshaft spacing since the folllower wheel or Rocker arm wheel is still 100% in contact with the 11-16 Style camshaft lobes. Now for the first problem. In an effort to reduce weight (among other things) the base circle of the GT350 camshafts were reduced, since the lifter bore locations were relatively unchanged a new roller rocker was required to fill the gap of the new smaller diameter base circle of the cam, the rockers also feature a different diameter wheel and thinner wheel to reduce friction. Ford Simply moved the centerline axis of the wheel to take up the gap caused by the new smaller base circle.
Many of you may be asking what this means for you. Basically if you want to run your existing stock or aftermarket 11-16 cams it requires the use of a Modified rocker arm (now available from MMR), the rocker arm has been clearanced to mimic the GT350 rocker arms because the camshaft will actually touch the rocker arm due to the extended valve heights of the GT350 head. Many of you may be asking "why cant I just use a GT350 rocker arm?" . The answer is that the GT350 rocker arm is not compatible with the base circle of the 11-16 cams and will hold the valve open due to its relocated wheel.
Other information you may need:
Head gaskets - You need to use 2015+ head gaskets due to the oil restrictor, GT350 gaskets can also be used but only suggested on a 3.700" bore
Bore Size - Yes, the valves do open and have adequate clearance for the std 3.630 2011-2016 Bore size
Valve Springs - The factory Valve springs have approx 60lbs of seat pressure, if your combination requires an upgrade these heads require a custom valve spring and retainer (due to the new valve length) MMR has them in stock with 2 options, see below
Camshafts - When using the MMR modified rocker arms any 2011-2016 Camshaft can be used
Other Options - Ford will be releasing custom cams later this month, many people think they are GT350 cams but they are not, they are cams made for Ford with GT350 specs but with the std 2011-2016 Firing order, they also require the 2015+ Timing chain and phaser kit (also now called the Gen2). These cams retail from MMR for $1399 but also require the GT350 rockers since these cams use a small base circle like the GT350 production cams.
Below is a picture of the GT350 heads using a 11-16 Camshaft and stock 11-16 Rocker arm, you can see it does not have adequate clearance between the rocker and the cam lobe.
Shown below is the modified Rocker from MMR, minimal material is removed in the CNC machine and this modification provides proper clearance.
A shot of the GT350 cylinder heads
Parts needed (we will update this list with links to the website shortly):
If you want to run your 11-16 Cams you will need:
MMR Modified Rocker arms - http://www.modularmotorsportsracing...ge=product_info&cPath=4_30_35&products_id=885
If your cams require upgraded valve springs you will need: http://www.modularmotorsportsracing...ge=product_info&cPath=4_30_35&products_id=850
2015-2016 Head Gaskets
If you want to run the new Ford Racing Cams Cams you will need:
The Ford Racing 5.2 Cams http://www.modularmotorsportsracing...page=product_info&cPath=26_27&products_id=893
2015-2016 Head gaskets
GT350 Rocker Arms
2015 + Timing Chain Kit http://www.modularmotorsportsracing...page=product_info&cPath=28_29&products_id=820
Any questions, feel free to ask anytime in this thread.
www.modularmotorsportsracing.com
