im planning on getting a new cam, comp 70-123-6, i was wondering if id be okay with just swapping the cam or if i should get the cam lifter combo kit. according to comp cams because its mild its okay with mostly stock components but ive got no experience on it either. can anyone shed some light on this?
Depending on mileage the stock springs may be a little weak but will work for a driver. Just swap cam & followers unless it's gonna see a lot of upper RPM use
ive only got 40k on it, so i cant imagine anything would be very weak. its really jsut a daily driver, although i do have a heavy foot at times
40K isn't too bad. Just swap the cam & followers & see how it runs. If you start getting valve float when you beat on it then look at springs.
with the followers, is that something that will need to basically be matched with the cam or is it just one of those swap it because its a good precaution kind of thing? the only followers im really finding are made by melling and are nothing exactly "special"
Yeah the followers need changed. Like lifters they wear with the cam lobes & can't be reused or mixed up if a used cam is installed. Stock Ford or aftermarket is fine as long as they are new. I've seen reground ones on Ebay but a new set is only $40-50 so why bother.
I'll overemphasize that, the cam will go flat unless you use new followers...............after that happens they are matched to lobe and must never be mixed up. Use the supplied break-in lube as well. Any good quality stock replacement follower will work on that low lift cam, the main thing is to get brand new wear surface there. Have a look at the middle 2 cam bearings too, they can sometimes be dead in 40K miles.........
With extra lift you should consider doing the 'collapsed lifter check' since you were apparently rebuilt 40K ago. If someone did not check then and left alone then you may run out of lifter internal movement and then valve be held slightly open to not run right, needless to say the cam goes bad pretty quick too since oil gets continually wiped off the lobe then. Back in the days when these were common many mechanics put together dead stock engines with valvejobs that raised valvetips and no regard for that and the result was the engine became known as one that 'could not be rebuilt successfully' which was a load of crap. Simple ignorance ruined all those engines.
That 40k isn't rebuilt miles. That's total on the car, not that that's necessarily relevant. I was planning on maybe doing new lifters anyway, they sell the cam kit which includes them for only about 30 more. I did end up ordering followers when I was at work today.
I'd still do that collapsed lifter check, I don't build a head on one of these engines without doing it unless all known working together parts going right back in. That one thing lost plenty of engines back in the day. Best friend worked at a machine shop that got blamed for 'faulty work' every time somebody failed a cam after not checking, it happened all the time.
What year? You wanna make d-mn sure the head has induction hardened exhaust seats, and may still show wear on exhausts early since that was done only to run with low lead, with zero lead now the exhaust seats will go right back to wearing more especially if ethanol added. With zero induction heat treat and zero lead fuel mine only went about 12-15K miles before brand new exhaust valves were DEAD, no way were you gonna grind them back into shape, nothing left to grind. '74 model, the year right before Ford began to do it.
its a 79. after a quick search online, im 99% sure that ive probably got a collapsed lifter. ive basically got a tick (some days) that gets better when i let off. In any case why do you recommend i check them if i'm replacing them?
That tick could be from a wiped lobe on the cam too. Sometimes a stuck lifter will take out a lobe.
That CAN happen however I should point out that the collapsed lifter check is not searching for collapsed lifters at all.
A collapsed lifter will make itself known pretty quick. The test actually describes the state the lifter is in to get the result which is a check that the running tappet has a range that lets the valve stay closing properly at all times. When you do head work the valves raise higher in head and the tips must be addressed by cutting them in varying amounts to restore the running clearance of the lifter top inside the lifter, idea being to keep it somewhere in the middle. If not some valves may be too long and then use up all the adjust distance inside the lifter, then the valve starts hanging open and engine running goes to crap. Left alone long enough and cam lobes begin to tear up since no oil on lobes now, the never having any clearance wipes all oil off.
AMC,
Can you explain the 'collapsed lifter check' with some detail? I'm at a point now with the rebuilt 2.0 for my Yellow Runabout I could do this- having this info in the thread will likely help many folks.
I'm thinking that this is only for the 2.3 since the 2.0 have no lifters? Is there something similar for the 2.0?
ONLY for a 2.3. On a 2.3 you remove the spring from the inside of an old lifter. You then install the lifter and check the gap between the rocker arm and the cam lobe. Should be .035 to .055 with .045 ideal. If its too much you will need to add shims under the lifter to get the ideal clearance. You now need to do the other 7.
Easier to simply squeeze the lifter oil out with a simple c-clamp if lifter out of engine and by hand. No dirt inside that way too, lifter internal valves very susceptible to dirt of any kind.
Idea is to get the lifter valve around the middle of the travel to make sure it is nowhere near the ends. When starting up a new engine you bleed the lifters down again by c-clamp also as if the valve tips have lengthened and lifter not collapsed then valve again held open possibly long enough to drive you crazy as lifters fill up to get tighter far easier than they drain back down to close down a bit. They are designed to not do that, why overrevving engine pumps them up to run like crap too.
The check is done with cam lobe nose directly opposite the follower contact point, or on the base circle. I have used a screwdriver to then slowly pry the lifter closed internally, then stick your feeler gauge in the gap between lobe and follower to check. The numbers as stated by dick1172............
No need on 2.0 as solid lifter already has clearance when you set the valves. Or it better have...........no real lifters on either engine per se, more like adjustable stands, one engine manual, the other hydraulic.