cam caps [Merged 6-7] camshaft camshafts bearings bearing seizing

[Razor_DSM]

for some reason i cannot turn the camshaft freely when i put a set of cam caps on my rebuilt head from 2 other heads it makes no difference. someone lost the original caps...
i didnt think there was a difference, im stumped on this one? im not really positve what year the head is, but id was pulled from a 91 AWD 5 speed talon. but there definatly isnt 90k on it in fact its almost brand new, so it was replaced at one point.

so are there dirrerences between the caps? are they all different (line bored)? how do i tell what year head this is. it does not have a 2.0L stamped into the spot above the water neck.. g67 is there...


oh man.... maybe someone put an elantra head on a awd turbo car? what other identifying mark are there and where to look, i definaly don't want to use a 124hp head
on a 400hp motor..


HELP

 

[Razor_DSM]

all the valves have 6T on them, the same as 3 junk turbo heads that i have, there are 3 1/4" drill indents on the front, directly above the exhaust manifold, the other turbo heads i own only have 1. other than that i looks identical to what it should, non turbo valves are supposed to be different than turbo one's, are they not?, this is so damn confusing.

 

[Defiant]

You can't swap cam bearings around. They must be align-honed.

 

[Razor_DSM]

how much would the average machine shop charge to get that done?

any idea what the g67 on the side of the head is all about. it seems the valve type (6T) is the same as the turbo ones, i just want to be positive its a turbo head before i dump money into it.

also the intake cam that was in it had an E cast on it, isnt that one of the low lift cams? definatly not what a 91 should come with. ive used the cam in a different head, a known 91 TSI head, seemed to work ok, lots of low end

 

[squeak10686]

ok so one of my friends gave me a 1g turbo head right... well it has 2 bent valves and i figured whatever you know its given to me ill take it... I know your supposed to have the ORIGINAL cam caps, but is there anything i can do so i can use this head with my car when rebuilding it????
Andrew

 

[RoasT BeeF]

Not unless you have the original caps.

 

[Defiant]

You would need to have the non-original-to-that-head caps shaved and align-bored. You can't do it for the $150 another (intact) head would cost you, I don't think, but ask your machine shops.

 

[lowridin2g]

this brings me to a question. i just bought a 1g head with recently new valve seals and cam seals 9,000 miles ago. anyway i plan on using my hks 272/272 cams out of my 2g head in the 1g head. would i use the caps off of the ig head or the caps off of the 2g head? im assuming off of the 1g head.

also is there anything else i should do, its gotta go to the machine shop to get the head decked, and to get an exhaust manistud that broke off in the head taken out, helicoiled and replced. just hope they can do it, its broken off flush in the head. should i have them put in new valve guides also? but if i do that i may as well put in new valve seals also while theyre already in there correct?

 

[ItsStockOfficer]

Caps stay with the original head in the original spots, always.

 

[RoasT BeeF]

Caps stay with the original head in the original spots, always.

Yup.

 

[1fast97gsx]

not arguing or disagreeing with anyone .. but what's the big deal about mismatched caps? I know they wear over time and a set with more miles will probably be worn more ... so I'm assuming the cam will wear faster. But how much faster are we really talking? Will it only last 500 miles, 5000 miles, 50000 miles or how bad is it to really mismatch caps. The reason I ask is I was in the same situation last year so I just used my stock caps. I ran the car for 4000 miles like that and when I took the engine back out ( machining error in bottom end ) the cams appeared to show no scoring. Just wanting to learn not start an arguement so polite explainations would be nice.

 

[Defiant]

not arguing or disagreeing with anyone .. but what's the big deal about mismatched caps?

It's not a matter of wear. For the bearing area and the amount of load, cam bearings are pretty much loafing. You lose some benefit from their being aluminum, but the problem is that the bearing surfaces are carved into the head and caps at the same time. If you try to swap from one head to another, the chances that the castings came up at the same place in the jig to bearing tolerances are about nil. With mis-matched camshaft caps, you won't get distances in thousands of miles, but in dozens of feet, snapping a cam or the drive belt when the bearing seizes. In the case of replacing the caps, you must mill down the mating surface on the bottom of the cap and then align bore and hone the assembly. While this may make sense in putting together a Jaguar X-K120MC with a head worth many thousands of dollars, it just doesn't pay off with good-running and clean used DSM heads going for a hundred.

 

[1fast97gsx]

ah ... well that just sucks. I had a head built up a while back ( bronze guides, 1mm+ ss valves, crower springs, retainers, decked, ported, and painted ) but the head didn't have cam caps. I figured I'd just use the ones off my old head ( wasn't thinking I guess ) so now I have a built head but no caps . Guess I'll call my machine shop and see how much it would cost to mill the caps and align bore / hone.

 

[Defiant]

Wow. And some shop did all that work without asking? I mean, this used to be new stuff, but that was 40 years ago.

 

[1fast97gsx]

yea ... makes you wonder how some of these shops are still around.

 

[bastarddsm]

becuase of people that have more money than they know what to do with. and the throw money at shops that to what ever they want, whether it is right or wrong.

 

[bad71camaro]

Well hear is the situation I am in. Just payed way to much for a 1g and it blew the head with in 10miles because they head was planned way below specs. So I had to buy a new head which I was lucky enough to find one only about 2hrs away. We met half way and I payed $140 it seemed to be in good shape. I drop it off the my mechanic and get a call saying that it needs cam caps and they can not be swaped from my head. I called around and this seemed to be very true. I call the guy up and asked him about this and he insited that he had swaped cam caps several times and that his reputable mechanic also sayed that it was ok to do this.
He sayed that he would just swap me anothere head that had the caps. Now he is acting real shady and cut are conversation very short. This time he sayed man your just pissing me off cause I no you can swap them and im out of town and I dont no when I will be able to do this. So me being the nice guy I am I said that I will drive the whole way up there to get the head and he says he will give me a call tomorow but I highly doubt that he will. So I guess the bottom line is I am wondering if any of you guys have actually switch caps and what were the results ? Also what would you guys do if you were in my position? I guess if I cant get strait with this a hole I should just look for anothere head cause extreme quoted me 300 to have them line honed. Man I have had my dsm 1month and only put 10miles on it I dont no if im ready for all of this hassle

 

[4g63awdtalon]

i know some one that had to but he had the cam jurnals align honed an dit worked out great for him

 

[igopoopy]

i did but my car is still not done yet

 

[fp-green-95tsi]

Without doing a line bore on them, i would not recommend swapping the caps. I have seen it twice. The first time the cams were so tight they could not be spun, the second time they were too loose and scard the cams pretty bad. I live in maryland, and have a few heads laying around if you'd like to take a look at one of them.

 

[Lee'sGSX]

They say it's not good to do so but I have swapped plenty of them and no problems.

 

[soulcontroller]

i wouldnt do it.

ive tried before, and the cams would not turn at all. bad news, wasted time, wasted head. pissed off.

just make sure you get a head with caps is all.

 

[bad71camaro]

Without doing a line bore on them, i would not recommend swapping the caps. I have seen it twice. The first time the cams were so tight they could not be spun, the second time they were too loose and scard the cams pretty bad. I live in maryland, and have a few heads laying around if you'd like to take a look at one of them.

Man that would be great what do you have and what would you be looking to get for them. Keep in mind im pretty broke I only live like 30min away. Just give me a call I sent you a pm thanks mike

 

[1fast97gsx]

I actually don't have caps on the head I was planning to use either. My machine shop said to test fit the cams and a different set of caps and meassure clearances with plastiguage ... then go from there. A line hone may be needed.

 

[RoasT BeeF]

It really isnt a good idea.