Lifters and what else?

[Da Big Blue]

Ok turns out the backfiring through the carb is because of bad lifters so i will be replacing those this week sometime. my questions are
1. On a scale from 1 to 10 how hard is this to do?
2. Anyone know of anyone who makes roller lifters for this engine?
3. While is was in there I was thinking of putting in a RV Cam or something and maybe some high pro headers.
Any suggestions where to go what brand names to look for.
4. What else should i do to booste the horse power?

every suggestion is appreciated.

Thanx

[ March 07, 2003, 02:44 PM: Message edited by: Special-K ]

[robselina]

I thought I was going to have to do this too, so I looked into it. First off, it's a LOT harder to replace the cams while you're in there. That requires removing timing chains and all kinds of stuff. It's a good thing to do, but it's not a "while I'm at it" sort of thing. Replacing the lifters doesn't seem THAT hard, just time consuming. I haven't done it though, so I'm speaking from what others told me, take it with a grain of salt. If you want more HP, I'd get a manifold from a 401 and drop a 4 barrel on there personally, that seems to be the best upgrade. Then maybe headers and exhaust, followed by the cams.

[Nobby]

New Lifters = New Camshaft and vice versa.

Pulling the camshaft isn't that big of a job. However new camshaft really should have a camshaft bearing appraisal to check to see if they are still within tolerance. There is no point in fitting a new camshaft in badly worn bearings unless you don't mind throwing money around.
Now replacing the camshaft bearings is not a quick job.

[dublt]

Nobby's right, "while yer in there". Don't stop there though, do a t-chain/gears too. In all reality tho, get your priorities straight and figure out a stoping point. It all hinges on time and money. Do what you can with what you got. BTW, I might be wrong, but isn't it bad to mix an old cam/new lifters and vice versa?

[4DWUDS]

IMHO you are just wasting your money on roller rockers on a street motor that will prolly never see over 4000 RPM. If you were talking roller lifters then you will need to change the cam to take advantage of the rollers also and then it would have to be a custome grind because I dont know of anybody that ever has or ever will makes that kind of cam for the AMC motor. Sounds like your best bet is just add a manifold, carb, and headers for the performance boost.
One clarifaction. It's OK to put new lifters on a old cam but not the other way around. If you pull any lifters out just make sure they go back in the same hole.Just dont change one or dont use a used lifter just cause your budgets tight. Change them all with new or dont change any of them.

[Nobby]

Good engineering practice would have you change the cam with new lifters. It isn't that much more expensive. So I disagree its not OK.
However putting the old lifters back wence they came is good advice, as is not mixing matching new and used lifters. To expand on this for any engine work always label mark and put the parts back to their original location.

Just out of curiosity what led you to your misfire/lifter diagnosis.

[Crazy_Jeepman]

Originally posted by Nobby:
Just out of curiosity what led you to your misfire/lifter diagnosis.I am also interested in hearing the answer to that. I have run into many flat cam collapsed lifters, bent pushrods, Can't say as I have ever had one backfire through the Carb. to backfire through the carb, the intake valve would have to be open on ignition, with collapsed lifter, wore out cam lobe or bent pushrods the valve would not be open. There are other reasons for backfiring through the carb, I doubt bad lifters would be it.

[andy d]

yeah, popping back thru the carb is usually either starving for fuel or an open intake valve during ignition. hows the timing chain? might be a stuck valve that could be freed with some marvel mystery oil or a few tablespoons of water. can you isolate the problem to a particular cylinder?

[letank]

How many miles on that beast?

you will hear collapse lifter.....

then get the tool... i did not get the tool, and with the varnish... it took me the all day to pull the lifters.... one was really stuck... i had to use a wise grip.... which shattered on lifter... i was glad i covered the valley with rags.... otherwise that big chunk of metal would have dropped down ....

What about a compression check.... dry and wet

cheers

Michel
74 wag

[4DWUDS]

Yes, Nobby is correct that Good engineering practice would say to change the cam along with the lifters and then you also should change timing chain and gears while you have it apart that far. But it is a common practice to just replace lifters if one has collapsed and or otherwise is malfunctioning. Again it is not "Good Engineering Practice" but it is still done every day.