bent pushrods

#1
ok well it seems the nomad needs repair.

60 nomad 348 250hp 4bbl

Well those who have seen the for sale forums know the story already

On a recent drive the car devolped a upper end tick on the left bank. I drove it home and pulled the vavle voer off and found 2 bent pushrods 2 almost wore though rocker studs and some messedup keepers.

Ive been serching the forum and internet for hours and got some ideas on what to do nexted. So ive come to ask the exprinced knowlegable people on 348-409.com.

I want to convert it to screw in studs and i was thinking of using mr gasket screw in studs due to its lack of head work. I plan on taking the heads of to install new vavle seals and to lap the vavles as well. o and what are some ideas for removing old studs is apretacted to.

I want to make it as relible as i can (well i would actually like to make it as strong as i can , bbc vavles and springs, 1.75 roller rockers and a 409 425hp cam but it to orignal to molest)

I need ideas for stock pushrods can i just use later one piece bbc pushrod as i hear the welded ball ends are crap and can i use bbc keepers as well.

Any ideas are very aprecated
 

Ronnie Russell

Well Known Member
Supporting Member 2
#2
250hp348,,,,,,,,,, There is only one way to do this job right. Take the heads off, take them to a machine shop. Have the old studs removed and replace with 7/16 big block screw in studs. The stud bosses need to be shaved the thickness of the screw in stud nuts. Order some Isky 5/16 chrome moly push rods. Roller rockers are available at a very reasonable price. Others can comment on which brand fit under the stock valve covers without clearance issues. Good luck ,,,
 

09Jud

Well Known Member
Supporting Member 2
#3
I agree with Ronnie and recomend push rod guide plates,dont forget to float them in before you tighten them all the way. Also check the top of the valve stem for flatness, and slop in valve guides. best of luck
 
#4
Thanks for the quick replies

I like the idea of guide plates to correct some vavle train geometry but where would i get a hold of guide plates looks like i could just make some.

Now where would i get some isky pushrods or do i just get some bbc rods. actually i i should get the machine work done and measure them myself ( but that would be the right way).

Ok i guess ill just contuine the taredown.

I still dont see what caused the pushrods to bend in the first place.

till later
 

Ronnie Russell

Well Known Member
Supporting Member 2
#5
You can try Phil Reed ( a member here) for the chome moly pushrods, if he does not carry these , you can order from Showcars. There is controversy as to the advantages and disadvantages of guide plates. They are available , should you choose to use them. I would imagine the bent pushrods were the result of rocker arms that were out of adjustment for a long period of time. Not uncommon for people that dont do regular maintenance. BTW, the pushrods are available in 348-409 std length replacements.
 
#7
Well we plan on driving to shows and swap meets till it sells. I would hate to sell a car and have it start ticking on the guy a week later. Also the market doesnt seem to be jumping on a 4dr wagon. well it would sell if I excepted some of the redicus offers ive been getting. The car has been in the family for a long time weve been talking about saying screw it and turning it into a restomod.

Mostly I would want to drive it to pomona at least once a month even just for fun and I work on it for fun not profit. I probaly wont get a chance to work on a w engine again.

O and it broke on me i almost feel guilty.

I dont know you guys are probably right well i just got both heads off 15 mins ago so least just say i took it apart to reseal it. (I think the intake was heavier than the 379 castings.
 
#8
Found 4 more push rods that are bent. After taking to my dad this motor was post o have been rebuilt 4000 miles before we got the car. We have never driven car more than 20 miles since we got it 14 years ago. This motor is very clean inside I guess some parts were carryed over that shouldnt have been. Or mayce all the once in a while starts put its toll on the vavle train. Later
 
#9
99% of the time, bent pushrods are due to mechanical interference or "unnatural" misalignment. HIGHLY unlikely that they're bent because they're old.
I'd be checking for coil bind at the valve springs.
 

09Jud

Well Known Member
Supporting Member 2
#10
Did you replace the springs and or push rods prier to this. Ive had problems with stock replacment push rods. if you put stonger springs that will bend push rods also. but do check the things talked about in the rest of this thread. Its not easy for anyone to find your problem with out seeing for themselves. check the wear pattern on the rocker tips ,the wear should not be much wider than the stem of the valve. If there is, more than likely the push rod guige holes are warn allowing the push rod to get at a bad angle.
 

1958 impala

Well Known Member
Supporting Member 5
#11
:cheers :cheers 250HP348
I think you should keep the car,:cheers get someone to adjust valves thats done it before.I think with new pushrods and afew rockers youll be happy with car again.Just my 2cents worth.
 
#12
Ok well i striped the heads of there vavles and springs and cleaned the head that had the damege. I ended up finding worn pushrod guides and i tryed removing the worn studs anyways, but ended up breaking both of them (i tryed twisteing them instead of pulling them ops i guess) so i tried drilling them but i dont like the results. Sooo... I need some new heads.

Anyone have a set of useable heads that they want to sell or trade for the only thing i have for a w engine a 3x2 intake i picked up. I would like to pick up in person as shipping would be expensive. So please if anyone is intersted with in 100 miles of plam springs would be great.
 
#14
I think ive seen that wagon before red? If its the one im thinking of is almost identical but the only place ive taken mine to was on a tralier at the pomona swap meet.
 

dq409

Well Known Member
Supporting Member 3
#17
Ok well i striped the heads of there vavles and springs and cleaned the head that had the damege. I ended up finding worn pushrod guides and i tryed removing the worn studs anyways, but ended up breaking both of them (i tryed twisteing them instead of pulling them ops i guess) so i tried drilling them but i dont like the results. Sooo... I need some new heads.

QUOTE]

:eek: :eek: :eek: Take those heads to a GOOD machine shop and quit butchering them !!!!:doh
 
#18
QUOTE]
:eek: :eek: :eek: Take those heads to a GOOD machine shop and quit butchering them !!!!:doh[/QUOTE]



WHOA!, JIMMM!;) ... you're sounding like ME:takethat :p


However, 250HP.... please try to bear in mind, these are not just generic, belly-button, nothing small block parts. You might want to be a bit more careful:coffee:
 

tripower

Well Known Member
Supporting Member 2
#19
Ok well i striped the heads of there vavles and springs and cleaned the head that had the damege. I ended up finding worn pushrod guides and i tryed removing the worn studs anyways, but ended up breaking both of them (i tryed twisteing them instead of pulling them ops i guess) so i tried drilling them but i dont like the results. Sooo... I need some new heads. .
I'm sorry but, when I read your post yesterday I had to bite my lip. I think you would be way better off letting a qualified machine shop do the necessary work on those heads. Removing the studs is not something you can do on the work bench and, finding another set of heads is not something that is just lying around under someones work bench. :doh
 

1958 delivery

Well Known Member
Supporting Member 2
#20
I think ive seen that wagon before red? If its the one im thinking of is almost identical but the only place ive taken mine to was on a tralier at the pomona swap meet.

Now that you mention it it may have been red. The guy was way over priced for the condition ($13000approx). It was in pretty bad shape, I talked to him briefly he was under the impression the this year of Nomad was as rare and sought after as the 1955-57 ones!
 
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