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-   -   351w valve train (http://www.hotrodders.com/forum/351w-valve-train-229811.html)

stewd8 02-20-2013 09:47 PM

351w valve train
 
hi guys, 351w problems i need help with.....the rocker wants to turn, forcing the push rod against the pushrod guide, wearing the pushrod in 1 miniute,,,then it bends,,,,
this is a fresh motor that i just built, the cam is a comp cam 06318
grind is xe268h,,,,its suppost to be prity lumpy, stock pushrods and rockers,,,any ideas

JeffB 02-21-2013 12:15 AM

Quote:

Originally Posted by stewd8 (Post 1648715)
hi guys, 351w problems i need help with.....the rocker wants to turn, forcing the push rod against the pushrod guide, wearing the pushrod in 1 miniute,,,then it bends,,,,
this is a fresh motor that i just built, the cam is a comp cam 06318
grind is xe268h,,,,its suppost to be prity lumpy, stock pushrods and rockers,,,any ideas

Stock pushrods? :nono: Stock valve springs? :nono: Order the Comp pushrod to check for proper length,you have a couple of ways to go you can order the correct length pushrods or get the shim kit http://www.summitracing.com/parts/crn-99170-1 for your rockers or get a good set of heads with screw in studs so you can run adjustable rockers.

stewd8 02-21-2013 10:50 AM

as far as i know they are stock, but how do i tell if there stock or not,,the heads have been modified with the screw in studs and are adjustable...with hyd lifters
this motor is in a small boat, and the guy that owned it before me put a lot of money into it,,,like 7000.00 ...i don't know what is stock and what is performance...the pushrod giudes are comp cam 4816,,so there not stock,,,wich leads my to thinking the springs and pushrods are not stock....but i don't know,,how can i tell???

Mr. P-Body 02-21-2013 11:20 AM

Rockers twisting and rubbing guideplates usually indicates a stud that's either bent or intalled at the "wrong" angle. If your valves have at least 1/4" above the locks, you can discard the guideplates and use "rail" rockers (later model Fords and Chevys have rocker s with "rails" to keep them centered on the valve). It's important to understand, only ONE method of "alignment" can be used. If more than one, it WILL "bind".

It's also possible, when the heads were machined for screw-in studs, the "slots" used to guide the pushrods weren't "opened". They should now be about a 1/2" diameter hole, NOT a slot. That too, WILL cause "bind".

Lastly, be certain the pushrods are "hardened" for use with guideplates. It will SAY SO on the package or in the product description. Generally, if not noted, they're NOT hardened.

FWIW

Jim

MouseFink 02-21-2013 11:49 AM

If your 351W has self aligning rail type rocker arms, you must use valves with .395" tips.
If your 351W does not have self aligning rail type rocker arms, you must use valves with .250" tips.

Make sure the valves are the correct type for the rocker arms you are using. Using valves that have .250" tips with self aligning rail type rocker arms will cause the rocker to run off the valve tips.

stewd8 02-21-2013 12:17 PM

Quote:

Originally Posted by Mr. P-Body (Post 1648905)
Rockers twisting and rubbing guideplates usually indicates a stud that's either bent or intalled at the "wrong" angle. If your valves have at least 1/4" above the locks, you can discard the guideplates and use "rail" rockers (later model Fords and Chevys have rocker s with "rails" to keep them centered on the valve). It's important to understand, only ONE method of "alignment" can be used. If more than one, it WILL "bind".

It's also possible, when the heads were machined for screw-in studs, the "slots" used to guide the pushrods weren't "opened". They should now be about a 1/2" diameter hole, NOT a slot. That too, WILL cause "bind".

Lastly, be certain the pushrods are "hardened" for use with guideplates. It will SAY SO on the package or in the product description. Generally, if not noted, they're NOT hardened.

FWIW

Jim


so, just to get this straight,,the comp cam rod guides, slots have to be widened, or machined bigger,....there is no rail or tube that runs the length of the head...i will buy new rods, just so i know there hardened
these rods i'm using were the ones out of this motor,,,used,,,will they have marks indicating hardness

Mr. P-Body 02-21-2013 02:53 PM

Stew,

No, usually not "marked". If there's a part number on them, we can certainly "find" which they are.

Machined into the castings, below the rockers, where the pushrods come through the head, there's a "slot" machined from the factory (if early heads). If that slot hasn't been "drilled" to a 1/2" hole, the pushrod WILL bind in the guideplate. If these heads were original with "bolt down" rockers, something is "out of whack".

MouseFink, I've seen the roller-tipped versions of the "rail" rockers used with success on the shorter tips. They "clear" the retainer. If "stock" rockers, I agree.

Jim

JeffB 02-21-2013 02:58 PM

At this point try to post some pictures of your heads so we can better evaluate what is going on.

cliff tate 02-21-2013 04:19 PM

351 winser
 
It is my understanding 351 w never used heads with slots to guyd push rods.they used rail rockers ,then went to capscrew holding a fulcrom. If heads converted to screw in studes and guides the head must be machined wher the screw in studs go by the width of guid plate. cliff

MouseFink 02-21-2013 04:30 PM

Stock 351W engines came with self-aligning rockers or with non-self aligning rockers. The long tip valves were only used with the self-aligning rockers for additional clearance of the keepers, not the retainers. The outer edge of the retainers are low enough to clear the self-aligning rocker arms, but the rails (nubs) on the self-aligning rocker arms will hit the keepers if the short tip valves are used.

Stock 351C engines only have non-self-aligning rockers with short tip valves.

stewd8 02-21-2013 05:51 PM

4 Attachment(s)
ok heres some pics,,,,hay thanks for all your knowlege...i have ordered a hardened pushrod and a new comp cam rod guide..$15.00...its a 14 foot sidewinder jet boat, that will be running 5500rpm all day

prumora1 02-21-2013 08:46 PM

the stock 351w heads are not slotted in the pushrod valley. so if its a large cam it will cause the pushrod to go against heads and bend the pushrods, second check for coil bind need about 80 to 100 thousandths for clearance.
third make sure your valves are set with pumped up lifters, especially on hyd. lifters, if set non pumped up can be set to tight and when lifters do pump up it will be to much and put you in to coil bind.

my question? are they a Rhodes style lifter, a anti-pump up.

stewd8 02-21-2013 09:50 PM

Quote:

Originally Posted by prumora1 (Post 1649105)
the stock 351w heads are not slotted in the pushrod valley. so if its a large cam it will cause the pushrod to go against heads and bend the pushrods, second check for coil bind need about 80 to 100 thousandths for clearance.
third make sure your valves are set with pumped up lifters, especially on hyd. lifters, if set non pumped up can be set to tight and when lifters do pump up it will be to much and put you in to coil bind.

my question? are they a Rhodes style lifter, a anti-pump up.

?????coil bind????
don't know what type lifters, but when they were out for over 2 months, i wanted to pump them up , i put them in some oil and put a pushrod in it and i could not get it to pump,,it would not move up and down,,,but they are not solid lifters,,,,as there is a oil hole in the side
it ran great, 50psi oil,,,oil coming out of the rocker, back of till click, tighten 1/2 turn, did the other side, and heard it snap from one of the first ones i did

painted jester 02-22-2013 12:58 PM

1 Attachment(s)
You must run long slot rockers on the 351 with that cam Or the rockers contact the stud and break or bend the push rods! I am a little curious as to how they stay aligned. If my memory serves me - the stock rockers have lips on either side of the valve stem contact area that keep them from jumping off to the side ( I cant remember)? I can't see in the pic if yours do! And your pics are blurry And ford solid forse oiling lifters do have a hole in the side!!!!!! You cant tell looking at a lifter if its solid or not:nono:!!!!!!!! There should be a hole in a solid lifter side just like a Hyd. and out the top through the push rod and the push rod end of the rocker to get forced oil to the rocker, ball, stud, and valve tip and to flood springs for cooling of springs and lubrication some lifters have holes in the bottom to force lube cam lobes!!

Jester
Best way to set Ford HYD. lifters!!!!! Compressed method do not pump them up:nono:! See pic posted!
Collapsed Hydr. Tappet Gap
8-CYLINDER Ford ENGINES lifters that are not pressurized yet will have slack and that is expected there is a spec for the actual end of the rocker to the tip of the valve when the lifter is bottomed out...


8-302 (5.0L) and 8-351 (5.8L) Allowable: 0.089-0.193 in. (2.260-4.902mm) Desired: 0.096-0.163 in. (2.438-4.140mm)


http://www.hotrodders.com/forum/atta...1&d=1361562899

stewd8 02-22-2013 07:28 PM

LONG SLOT ROCKERS..... is that what i ask for at the parts store???? even if i have the short tip valves


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