Need help, Comp Cams stage 2 on GEN 2

S

SVT Zorro

Member
I need some help :headscratch: , I have a set of Comp Cams stage 2 grind number XE270AH PART # 102600. Lift is .55 Intake & .55 Exhaust , duration Intake 234 Exhaust 238

My question is if this cams are used on a 5.4 Lightning motor does the Piston will need notch for valve relief? my first though is no because piston on 5.4 sits lower :tu compare to its little brother 4.6 :scared1:

I'm asking this because I bought a Ford Lightning GEN 2 with a MMR 1000 engine with bad motor (previous owner though cracked block). when a took apart engine I found the problem (the 2 freeze plugs inside the timing chain cover were popped out) so engine is on process of being rebuilt.
Engine does have the Manley rotating assembly with spherical dish piston -18 cc
I notice when I remove engine heads I notice a slight marks on piston & valves :headscratch: like they hit each other (a very slight marks) on one side they look like intake valves were hitting and on the other side the exhaust valves were hitting.
It seems to me that the timing was not set right or the chain stretched or the chain main tensioners failed or all of the above.

I called MMR and they told me that those cams will fit with those pistons and that 5.4 can take cams with aggressive lift compare to 4.6 because piston sits lower in the hole....

Have any one have or know about the issue? please advice , have plans to put back same cams.. :scared1: when engine is ready..
 
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SVT Zorro said:
I need some help :headscratch: , I have a set of Comp Cams stage 2 grind number XE270AH PART # 102600. basically ad lift is .55 Intake & .55 Exhaust , duration Int 234 Exh 238

My question is if this cams are used on a 5.4 Lightning motor does the Piston will need notch for valve relief? my first though is no because piston on 5.4 sits lower :tu compare to its little brother 4.6 :scared1:

I'm asking this because I bought a Ford Lightning GEN 2 with a MMR 1000 engine with bad motor (previous owner though cracked block). when a took apart engine I found the problem (the 2 freeze plugs inside the timing chain cover were popped out) so engine is on process of being rebuilt.
Engine does have the Manley rotating assembly with spherical dish piston -18 cc
I notice when I remove engine heads I notice a slight marks on piston & valves :headscratch: like they hit each other (a very slight marks) on one side they look like intake valves were hitting and on the other side the exhaust valves were hitting.
It seems to me that the timing was not set right or the chain stretched or the chain main tensioners failed or all of the above.
I called MMR and they told me that those cams will fit with those pistons and that 5.4 can take cams with aggressive lift compare to 4.6 because piston sits lower in the hole....

Have any one have or know about the issue? please advice , have plans to put back same cams.. :scared1: when engine is ready..
Click to expand...

Mark at MMR would know.
Also Comp cams would know.
Make sure you have the correct springs.
 
I ran those exact cams on my 5.4L with no issues. Dish size does not matter as the valves will hit the top of the piston if there was interference. The pistons sit .120" deep on the 5.4 engines. Run them and enjoy, great street cam
 
I was told this motor does have Patriot ported Heads but could not find any invoice of these heads but heads look like they are ported (just by comparing with intake gaskets)


So when I said that slight marks on valves/pistons, was this caused by bad timing set up and/or bad timing chain and/or bad chain tensioner could lead to this? because this slight marks were on one side on intake valves on passenger side head and on the driver side head on exhaust valves...that make wonder this happened because cams got off timing somehow,,,,,any comments on that?
 
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Just dropped the rebuilt MMR1000 engine with these cams and works great, no piston notch required nor bigger stall....
 
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