Picked XE270HR-14 cam to go with my GT40p's should i upgrade springs?

[Yellow302]

Title says it all, between the tools and parts its another 200 bucks...

Using GT40p's from a 2000 explorer 80k miles long block

the lift in the cam is 512.. is that too much for the stock valve springs to handle?

 

[Vipersix]

It isn't absolutely necessary but it is definitely recommended.

 

[rj95svt]

It is absolutely necessary!!!!! The comp cam has very aggressive ramp rates and will be more likely to float the valves than a older design cam. The stock valve springs also will coil bind somewhat close to that lift.

 

[Yellow302]

Thanks i thought it needed to be done


CRN-44308-1 - Valve Springs/Retainers, Single Springs, Steel Retainers, Steel Locks, Single Groove, Kit

they are good up to .550-.560 lift

i should be good with these and they aren't that expensive

 

[rj95svt]

Are those the crane springs?

I ordered a set of springs from thumper for my GT40's and crower 15511.

 

[grngt50]

FWIW, I have the GT40p's as well and had the stock springs tested............they are good for stock applications only. I confirmed this with a tech at Ford Racing who told me the springs were good for .480 lift.

-James

 

[Yellow302]

nice, yes they are crane springs. looking forward to doing more crap that ive never done before

 

[rj95svt]

I have been building a motor for my car recently. I bought a crower 15511 cam for my build. I installed the cam in my shortblock ealier this week and degreed the cam( a new experience). Make sure you do this!! My cam was 4 degrees retarded when installed dot to dot. I advanced it 4 degrees and everything is great now. I'll never install a cam without degreeing it again.

 

[blksn955.o]

Actually you may want to go back and set that back dot to dot...a lot of new cam designs are setup with 4* on purpose.

I called TFS way back when I first got my TFS1 cam and they 100% recomended running it dot to dot. I later saw several posts about this on Hardcore and even found it mentioned in one of the articles I had when I researched cams for my combo.

IIRC even FTI's custom cams have some degree of this depending on needs.

Stock springs FTL...get new ones. Call the cam maker and ask questions about seat press. and stuff to make sure you springs are the best possible fit. Lift is only part of the EQ. You have seat pres., open pres., ramp rate, lift to look at. Most springs in the .550 should be good but better safe than sorry since its just a phonecall to the info.

If your getting any machine work done to the heads to freshen them up ask the mech. shop. I did and said "I am thinking about going to 1.7rr at some point and the cam specs are for 1.6. So that is why I am looking for something safe to .550 if that effects the seat pres. stuff that is why I am telling you".

 

[Yellow302]

sounds good, ill give them a call and see what they say.

 

[rj95svt]

Actually you may want to go back and set that back dot to dot...a lot of new cam designs are setup with 4* on purpose.

I called TFS way back when I first got my TFS1 cam and they 100% recomended running it dot to dot. I later saw several posts about this on Hardcore and even found it mentioned in one of the articles I had when I researched cams for my combo.

IIRC even FTI's custom cams have some degree of this depending on needs.

Stock springs FTL...get new ones. Call the cam maker and ask questions about seat press. and stuff to make sure you springs are the best possible fit. Lift is only part of the EQ. You have seat pres., open pres., ramp rate, lift to look at. Most springs in the .550 should be good but better safe than sorry since its just a phonecall to the info.

If your getting any machine work done to the heads to freshen them up ask the mech. shop. I did and said "I am thinking about going to 1.7rr at some point and the cam specs are for 1.6. So that is why I am looking for something safe to .550 if that effects the seat pres. stuff that is why I am telling you".

I used the .050 lift valve events to degree the cam to what the cam manufacturer suggests. I know that some cam grinders grind in 4 degrees advance but I've never heard of one ground 4 degrees retarded.

 

[blksn955.o]

Damn-nit, I missed that part...

yeah that is odd.

 

[Yellow302]

last time i installed a cam was last summer, it was a ford e-303 just said on the card it comes with to install dot to dot for best results.. so thats what i did.

 

[rj95svt]

last time i installed a cam was last summer, it was a ford e-303 just said on the card it comes with to install dot to dot for best results.. so thats what i did.

The problem with that is due to inconsistancies of the where the keyway is positioned on the crank and differences in the timing chain set the E303 you installed could have been 4 degrees off in either direction.