|02-26-2013 09:29 PM|
I had the same problem a long while back. come to find out that the lifter was not letting the valve open. I would check the lifter or you might have a bent valve or guide.
|02-25-2013 06:17 PM|
|stewd8||JUST A BACKWORDS THOUGHT,,,, while cleaning the garage today i found a stock 351w cam shaft,,,,,lose some power but it will run smooth, till the roller rockers come in.....|
|02-25-2013 12:12 PM|
From the appearance of the wear pattern on the push rods and the rocker arms, you should get rid of the push rod alignment plates and use self aligning rocker arms. That is evident by the round push rods holes that are about 1/2" in diameter, which indicates the heads are designed for self aligning rocker arms. Unfortunately, lash caps will not help because they are too large in diameter to fit self aligning rocker arms, therefore you must use 351W Ford long tip valves with self aligning rocker arms. Long slot, self aligning rocker arms that are designed for high lift camshafts are available from specialty auto parts retailers such as Summit or Jegs. In short, you're screwed.
The wear pattern on the push rods indicates they are binding against the alignment plates. Never use two methods of push rod alignment due to alignent problems.The wear pattern on the rocker studs indicates the rocker slot is too short for the amount of valve lift.
|02-25-2013 11:19 AM|
|stewd8||yesterday i removed all the rockers and studs,,,there is wear marks on all but one of the studs,,,i'm looking at some nice roller rockers 1.6 3/8 ,,,if and when i get them, i'll put them in and double check the geomitry is right, and all should be good|
|02-25-2013 07:53 AM|
good post 1
i am in favor of not pumping lifters while asembling.Bolt the rockers up then with spark plugs out turn the engin to #1 tdc,you can manually compress the lifter to insure (a) it is off the snap ring( b) it is not at the bottem of travel( c) )ther is no clearance at the valve. then go threw the fireing order check them all.you can use a soft wire to be sure each cyl is tdc.with plugs out easey to turn engine. if lifters are pumped up with a big screwdriver and slow constant presure you can collaps the lifterand make same checks,just harder.pros will chuckel at this methed but it is fool proof.just my thoughts cliff
|02-25-2013 06:16 AM|
everybody take a good look at there sbf's. since the late 60's ford has used positive stop rockers in all of there small blocks until 1986 where things slowly started to change. 1 there pedestal mount meaning that they are a positive stop and you tighten them down all the way, and how is the difference made up? when the lifter pumps up! same way as your Chrysler small blocks with the rail rockers.
In 1986 ford started with the efi engines to start changing them over to roller motors, and even then they were still positive stop rockers. its when there are those who try to convert the stock cast iron heads over to a fully adjustable, which there's nothing wrong with, unless its done wrong.
there are those who say that pumping up the lifters is wrong, but I can argue the same point without pumping them up, I guess its your preference. after all we're looking for advice, not a darn lecture of what everyone else is doing wrong. everyone has opinions and advice just like buttholes.
|02-24-2013 12:21 AM|
hay thanks guys, i learned a lot from you,,,, i found this that explains alot
i'll let you know, when i get it all figured
one thing,,,,how do i know if the pedistals have been machined down,,,
do you have a stock height, or a machined height that i can measure mine
|02-23-2013 08:29 PM|
|02-23-2013 05:33 PM|
this motor came in a boat, i just bought, that was windowed,,,the previose owner blue a piston into 80 pieces,,,the wrist pin went through the cylinder wall,,,,i got a used block and put all the pieces in and on, with new matching piston, wrist pin, con rod, all new bearings,,,
i do know he put $7000.00 into the boat, most into the engine...
i then put all his parts into this newblock,,,# match block,,,
just guessing it was all done right couse he had 500 hours on it, from his rebuild....there are other factors that coused the engine to blow,,,like running with no water and over heated,,,,,,,
where can i find out more about valve train geometry,,,in laymans terms
|02-23-2013 04:49 PM|
The earliest Windsors had the same "adjustable" valve train the 289 and early 302s had. There was an engineering change called "Change L-4". It was mid-69, when all the small blocks got the "positive stop" nut/stud combo and a specific valve stem "height". In the "machine shop", we have a book with the spec in it, as to how tall the valve is in relation to the spring perch. Theorhetically, if you hit that number, torque the nut to 20 lbs. (or is the Ford 15?), and have the "stock" pushrod, the lifter will "self-center". Most V8 engines from the late '50s-on, used this method for hydraulics. Unless the head(s) has been milled significntly in the past, this method is pretty much fool-proof. We use a dial indicator, but there are other tools, "Swifty Gage" being the most popular for a mechanic. Some shops aren't aware, or don't take the time. Any GOOD builder knows all about it.
From looking at the pics, the holes I spoke of are okay (can't tell the year of the head from the pic). The stud bosses LOOK okay, but I can't tell if there's an "angle problem" from a pic.
The assertion that coil bind could cause this is valid. It's rare, but I HAVE seen it. Usually, they pop the tip off the valve at the keeper groove, the valve "drops" and BOOM!
The installed height needs to be measured and the spring checked against it. You can remove the spring without pulling the head using compressed air and a "lever type" valve spring compressor. Having an experienced engine builder on hand to do the measuring may be called for.
|02-23-2013 02:44 PM|
Seems like only us old farts Know these little things I guess in this new age even Ford enthusiasts never learned the old ways!
I forgot so much since those times, from the early Chrysler & Ford engines, but I remember the valve trains!!!
|02-23-2013 02:33 PM|
|02-23-2013 01:56 PM|
Their are non adjustable rockers and adjustments are made with longer or shorter push rods or lash caps!
There are Conversions or some stock that you can adjust like Chevy small blocks, but the valve train geometry has to be right!
We have no Idea what size cam came out and the difference it would make to the geometry! The OP didn't Know what spring bind was so I'm guessing He is a novice, I'm guessing that's why he chose an auto cam instead of marine cam!
His old cam (I'm guessing) was a solid he stated he couldn't compress the lifters even after 2 months, on a hydro lifter they will at least compress between the pushrod pocket and the plunger down off the lock ring!
I worked for Fords for many years and was sponsored by Ford during the 60s during the FX Thunderbolt era, and never met or saw a Ford guy install pumped up lifters!!! unless they were the used ones going back on the old cam! And to say they can't be adjusted dry is a wrong statement And lifters will not make up the difference when pumped up that's why Ford checked valve train geometry by the compression method and had lash caps and push rods in our parts room to make the alterations, some engines could have longer push rods on just 1 or 2 cylinders. Right from the Factory! That was one of the reasons you put push rods back in the exact order you removed them from and the same with lifters, and with lash caps! If the OP just threw his parts together and didnt set them out in order he may have trouble and now the push rods are bent so you cant compare lengths!!!!
On a dual grind cam if that's what the old one was the last blue printer may have had different length push rods on the exhaust then the intakes!!!!! The other thing to consider if he went to a bigger cam is valve to piston clearance especially at 5500 RPM all day long on a close tolerance engine! If that engine was blue printed for the last cam there may not be clearance for a bigger lift? You cant just stab any cam in a custom blue printed engine ,If thats what he has?
|02-23-2013 01:51 PM|
|02-23-2013 01:07 PM|
yes i found wear marks on the studs, from the rockers,
silly question , but can i die grinder the rockers in to long slots, couse these rockers are new and unreturnable, and i don't need them sitting around here...
i did not buy them,,,they came with the motor
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