Daz

iTrader: (1)

Just replaced a broken pushrod(tip was missing),set the lash ran it with the covers off.Cylinder no one's intake rocker(or valve)was almost stationary while the exhaust rocker is barely moving the rest (3,5,7,)were moving..My guess is either a sticking lifter or a rounded cam lobe..anymore suggestions??

Daz

RB83L69

Rolled cam lobe... bummer

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"So many Mustangs, so little time..."
ICON Motorsports

ede

i agree with rb it's time for a new cam. i'd look in the lunati catalog for a replacement.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

Daz

iTrader: (1)

any idea what caused it???i dont want to make the same mistake

daz

RB83L69

Well, tell us a little history, maybe we can guess what caused it. Include what kind & year of block it is, and what cam and above all, what valve springs. If this is a performance cam of almost any sort and stock valve springs, there's your answer.

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"So many Mustangs, so little time..."
ICON Motorsports

[This message has been edited by RB83L69 (edited June 28, 2001).]

Daz

iTrader: (1)

87 IROC stock block
SCAT 93503755L stroker crank..

Cam is a Comp cams 08-305-8

220/230@50 .510/.510 lift 114 LS
Springs is the Comp cams recommended 986-16,rockers are 1.5 ratio Crane Gold(full roller)pushrods are COmp 7809-16(geometry was checked)..All of this on a 5 angle TFS heads(if it matters)3 cuts on the valve 2 on the seat...

I shift at 6000-6500 (too high?)
I did get loud bang when I try to start it without the no. spark plug installed(this it?)

appreciate any info

Daz

Daz

iTrader: (1)

to add: DOes that mean I have to pull the engine out to clean of all debris???Or is there a way around it???

Daz

Vader

There is no really good way around it. You could remove the oil pan to clean up, but since that would require at least raising the engine, you might as well raise it a few more feet and do the job right. You'll get a much better pan seal that way, too.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

RB83L69

The part selection looks right. Did anyone check the installed height of the springs? I was just looking that up on those exact springs for another motor earlier today, Comp calls for 1.75"... Also, did you check for lack of interference between the retainers and the valve guides?

It would be extremely wise to pull the pan off and clean out the metal which pretty much requires pulling the motor. Doing a cam swap will already put you about 2/3 of the way there anyway. While you're there, check at least the #1 main bearing and make sure that metal shavings haven't already gotten in there. You may also find that there are more lobes damaged than just the one, if it was an assembly problem.

That's a bunch of money, especially if there's more than just the one lobe (and therefore lifter) damaged...

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"So many Mustangs, so little time..."
ICON Motorsports

Daz

iTrader: (1)

I was told by the builder that the springs were measured..but who knows..

I dont get "lack of inteference" though ..pls elaborate


I assume that the different ride height would mean diff geometry???


Daz

RB83L69

The interference in question, is when the valve is open, how much more can it open before the retainer runs into the top of the valve guide?

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"So many Mustangs, so little time..."
ICON Motorsports

99Hawk120

You're probably not going to want to hear this, but if you rounded one lobe (maybe more than 1), there's a good chance the cam bearings are shot as well. And possibly even one or more of the mains (as RB said).

I pulled apart a 355 with 3 or 4 rolled lobes... metal everywhere. Every single bearing in the motor was toasted (some worse than others).


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