That wasn't an easy statement to make.
My hat's off to you, my friend.

FF

 

I'm just glad all of this information came to my attention BEFORE my engine was done. To continue the learning process can you explain about preloading the lifters in the modular heads? I know how to do it on pushrods but I am not aware of any adjustments on the mod heads. If you could elaborate on what they should be loaded to also that would be helpful. I know you don't want to tell all of your secrets on here so if you can't that's fine. I want to make sure I have full understanding about what needs to be done to make my truck run it's absolute best when it's done. Much thought and personal debate have gone into trying to decide on cams and so on with my upcoming head work and I want to be as informed as I possibly can be in order to make the most intelligent decisions I can to ensure nothing is left to chance. 3K is looking more like a bargain for heads to me now, whether it's due to the lack of information available from the other head builders making the JDM ones look much better or just the fact that they ARE better. My L is a DD and will remain so for a while to come so reliability is important to me. I am in no way afraid to spend money but I do want to make sure that if I spend an extra 500 then I am getting 500 worth of extra performance or whatever, you know what I mean.

I will agree that this has been one of the most informative and interesting threads I have ever read.

 

Jim

I've been friends with Jim's, JDM, and all their customers since the day I bought my Lightning, (over 4 years now) and although we were always good friends I too never did much business because I always found what I thought was a better deal elsewhere. When I look back at the 5 diff Chips I've bought, 7 Upper Pulleys, 5 Lower pulleys, 2 built motors, 2 ported eatons, 4 differant air systems, 3 cat backs, bla bla bla
BELIEVE ME WHEN I TELL YOU I COULD HAVE SAVED 15K BY GOING THERE DAY ONE.

Some get upset because Jim does have a certain set up he insist your truck has to perform correctly, but man I can not tell you how frigging amazing my Lightning drives these days. To be able to drive around with over 550 HP 24/7
"on my winter tune", 580 and over 600HP for the warmer weather and racing, is simply a dream come true for me. What amazes me daily is the tuning, the drivability, and the throttle response, not to mention amazing gas mileage, (it's actually getting better mpg around the street than my v-6 Mitsu).
My L needs each and every piece it now has on it, and there's a lot on it

But the icing on the cake was the things he fixed I didnt know were broke, the changes he made I didnt ask for, (or get charged for in some cases), the attention to detail and workmanship truly is second to none. Add to that the time, effort, and knowledge he's put into his motor program, the results he's getting out of them on the 1320 (and longevity). And belive me when I tell from experience, IT'S CHEAPER IN THE LONG RUN
I could have save A TON by doing it once, and doing it right

 

...all this information is priceless. I would probably have never learned this without reading it here. One of the finest post in f150online in a while!!
-OJ

 

Rob, thats my thoughts exactly! I learned LONG ago not to doubt his thought process! In a world where people are constantly trying to rip you off, I was very sceptical when first dealing with JDM. But they have NOT ONCE EVER led me down the wrong path!!! I may have felt like I was buying stuff on his advice that I didn't need, or could have done cheaper, but in the grand scheme of things, I can clearly see that Jim/me have made all the right choices for my truck.

BTW....Jim....you wanna throw a set of them springs in my truck when it comes in for its next tune in a couple weeks? Pretty please!!!!

 

I would like to thank Jim And Charles also. I think this information will save quite a few Lightning Owners some $$$ and Heartache.

Jim

 

We spend about 8 hours on each head during our assembly process. First thing is we get the heads back from being CNC'd. Then we use another machine to do the valve job its called certy, what it does is allow you to do each valve at exactly the same depth during the process of the 3 angle valve job. Each angle of the valve job are made exact using this machine. This way each valve stem will arrive at the same height when you set the valve in the guide. This process is done after you determine the proper height of valve stem for your lifter preload.

For those of you who want to check lifter preload, what you have to do is make sure your cam is installed in the head with out cam followers or lifters. Then you get an old lifter, there is a retainer on the top of the lifter that hold plunger in place. You pop the retainer off, pull the plunger out and remove the spring that is inside the lifter. Then you put the plunger back in the lifter with out the spring. This will give you full collapsed travel. Now you stick that lifter in your lifter hole, rotate the cam to the back side of the lobe, The back side of the cam is the side without the lobe. At this point you reinstall your cam follower where you just installed your lifter and get your feeler gauges out and make sure you have .050" clearance between the backside of the cam and the top of the roller on the cam follower. If you dont see .050" the only way to gain this clearance is to tip the valve. That means the top of the valve must be cut down. This is the reason why we use the Certy machine to make sure every one is within .001-.002." A good certy machine will run you $120,000! Factory Ford is around .020"-.025" clearance. I have seen some heads from other manufacturers that have had 0 clearance to only .010" clearance and some where the valve was actually held off the seat. A good range is between .040" and .055"

Hope this helps, I have enjoyed posting this hopefully next season we'll see alot more L's running faster out there because of this information!

Jim@JDM

 

I am honored and humble in your presence sir

I think I actually got wood reading all this stuff, Jim will you adopt me as the son you never wanted?

 

Get off the computer and have some beers birthday boy.. I mean OLD birthday boy. LOL

 

Quick question: Would stonger valve springs make a difference on a N/A engine? Such as a 5.4 with PI heads and headers?

 

Without a decent set of aftermarket cams or forced induction I would say no.

 

And at least one L running faster and a more reliable daily driver here in the UK

 

Thanks again for all the info Jim. I think I see a set of JDM heads in my future.....

 

We tested several valve springs and found the following:

Stock springs:
74.5# @ 1.640 (VC)
184.5# @ 1.090 (VO) (.550” lift)

Comp Cams PN# 26113-16
80# @ 1.64” (VC)
183# @ 1.09 (VO)

Crowler
90# @ 1.640” (VC)
242# @ 1.090” VO)

Manley
95# @ 1.640” (VC)
240# @ 1.090” (VO)

Note: Comp Cam springs are really not much stronger then stock.


Charles

 

No, it's not "certy", it's "Serdi". So, whoever the "we" is, it obviously isn't you.