stock hyd. roller lifter failure

[ybslowrun10s]

I have a stock bottom end 5.0 with FULLY ported e7te's. I milled the heads
.040" to up compression. Then fly cut the pistons to gain proper piston to valve clearance with an x303 cam and 1.7 crane roller rockers (from a 93 cobra). I also have 1 5/8" full lenth bbk's, 3.73's, 3500 stall, reverse manual valve body, fully ported 289 torker intake, holley 750 vac sec.
I put about 2000 miles on motor shifting at 6500 easily. It only ran 13.95's at 100 mph I havent had time to dail in the carb it was incredibly lean the plugs were bone white. anyway one day im on my way to town i dont get a 1/2 mile and i here an awefull noise and the motor starts to miss badly. i turned around got it home and tore it down. #7 intake broke a corner of the dog bone off and rotated 90 deg and the cam knocked off the roller. then i found other lifters about to loose theyre rollers also like they couldnt take the abuse of all the lift. i was at 3500 rpm when it let go but because of other lifters going bad id say they been getting weak for a while. sorry so long just wanted to try to give all the info. any help would be greatly appreciated. this motor ran and felt very strong. oh yea the heads have after market springs and retainers on stock valves. and the valves wasnt floating at 6500 rpm so i think all of that was ok.

 

[LarsD]

You knocked .040 off the heads, did you make sure the push rods were the correct length?

 

[BlownFiveLiter]

You knocked .040 off the heads, did you make sure the push rods were the correct length?

That's my first thought, too. The X cam isn't too radical a grind for the factory hydraulic rollers to handle. Something is binding up somewhere, or you're having PTV clearance issues. You said they're E7 heads and 1.7 rockers with an X cam? What valve springs are you running? You have .576" of lift, that's quite a bit if you're not running some sort of upgraded springs.

 

[2000xp8]

This combination sounds mismatched to begin with, then you are running it up to 6500rpm?
I believe the max suggested rpm for the x is 6200rpm, and i don't think ported or not e7's make any power up that high.
Flycutting the pistons isn't worth the trouble either for a set of e7's.
This setup sounds like a valvetrain disaster.
If you get it back together i'd tone the cam down to like an e with 1.6's.

 

[larrym1961]

I concure!

 

[ybslowrun10s]

well i found someone running almost the same cam just a little more dur. shifting at 7800 rpm with the same lifters. I thought the valve springs were for .600 lift but as it turns out this means nothing. the spring pressure isnt right. the lifters were coming up off the cam and slamming back into the cam. almost every lifter has wear and is ready to break. hard lesson, learned check everything. thanks for the help.

 

[2000xp8]

You sure you are getting accurate info? Keep in mind there are guys here with completely custom setups that run nowhere near 7800rpm. Then throw hydralic lifters into the mix, and i'd say there are none that do it.
Remember it's a stock block mustang, not a ferarri.
Almost nobody here even removes the stock limiter, not because they can't, but because there is really any point to it, 6250rpm takes more airlow than most parts will allow, so 7800rpm is insanity.

 

[Shaolin Crane]

You sure you are getting accurate info? Keep in mind there are guys here with completely custom setups that run nowhere near 7800rpm. Then throw hydralic lifters into the mix, and i'd say there are none that do it.
Remember it's a stock block mustang, not a ferarri.
Almost nobody here even removes the stock limiter, not because they can't, but because there is really any point to it, 6250rpm takes more airlow than most parts will allow, so 7800rpm is insanity.

Yeah 7800 is up there. I'd say the highest common RPM range is the 7000-7200 range. My combo is going to be a 7000rpm engine, but morel linked lifters, custom grind and a good flowing intake was needed.

 

[NIKwoaC]

Yea, I think someone is yanking your chain if they're telling you that they are running 7800 RPM on the stock lifters.

 

[ybslowrun10s]

no this guy is legit i have read so much i cant remember his name but its a 331 with brodix heads and an anderson 111 cam ( funny how i can remember that but not his name lol) and i have seen my best friend hit 7000 rpm with a stock 5.0 and a procharger on the street when it was wide open and the tires find a dip in the road or a slick spot. But that was a stock cam which requires very little spring pressure. I assumed that rooler lifters would be fine with after market springs "rated" for .600 lift. My mistake should have checked the spring pressure. also i have a carb with duraspark no rev limiter. Since i have 1.7 roller rockers im going to go with a smaller cam this time i was just using part i found real cheap, but now its not cheap. again thanks for all the input and hopefully ill get it right this time.

 

[ybslow]

I finally got it all back together. After further investigation I found that 7 other lifters were ready to break. Theyre sides were ground away. The cam bolt came loose and the cam slid to the back of the motor and was grinding against 8 lifters. $1.00 worth of lock tite would have stopped this. So I boight a new F cam and plate and roller timing chain kit that included a new cam bolt. And of coarse I used lock tite and torgued everything. Even with .040 off the heads the push rod length is perfect and it runs aewsome. the last time the motor was together it burned oil. I figured it was because it was a new block and I didnt hone it. The pistons were clean about a .5 inch in all around the edges. I have built many motors for myself and friends. I have NEVER had one not seal. So this time I honed the cylinders as usual and it is still smoking very bad espcially under wide open throttle. I was wondering if anyone has ever encountered this problem and found that it was something other than the rings. i did install new rings top one molly. it is an 1987 rotating assembly with a new 5.0 block from summit. its just wierd that it used oil before without honing and it still is using oil with honing and new rings. I changed the pvc and its the same valve covers ive had on other motors that didnt burn oil. my compression is 175 lbs on all 8 cylinders. any info would be greatly appreciated.

 

[ybslow]

oh yea ybslow and ybslowrun10s are both me i couldnt remember my pass word so i made a new name but then i remembered it. lol

 

[Rick 91GT]

I know you solved your issue but I thought Id comment. 9000+ rpm is capable with stock lifters

 

[ybslow]

WOW I did not know that. Im just trying to have a decent street car that I race once in a while at mason dixon street race nights. but this is my pacifier car my true love is my 85 notch that I have been collecting parts for for many years now. so far I have a set of tfs twisted wedge r's roller windsor block and a finished set of windsor truck rods and oil pan and pick up for a 351 windsor in a fox body. I want to build a 393 for the 85 thanks for the info I was looking at your web site I may contact you when getting closer to that 393 build. Ive seen Perky run before that motor does sound aewsome.

 

[Rick 91GT]

Yeah you are close to me if you need anything let me know I can usually beat Summit and JEGS. Im in Hanover, PA. The website is being worked on it is very out dated.

 

[f8tlfiveo]

Yeah you are close to me if you need anything let me know I can usually beat Summit and JEGS. Im in Hanover, PA. The website is being worked on it is very out dated.

wow.. I didn't know you were that close to me.. Im right outside Lancaster pa..

 

[ybslow]

yea thats not far ill keep that in mind thanks