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

 

[Turbo Monk3y]

im following on what you guys are saying about how it is a bad idea for switching Cam caps, But what about switching Cams themselves??? wouldnt that be kinda the same thing??? Or are cam caps machined a little different then the cams themselves??? I have 3 6 bolt heads lying around and i was thinking about switching the Cams over to another head because they are brand new. is this a good idea of i use the original cam caps to that head????

 

[RoasT BeeF]

Switching cams is fine. The caps should always stay with the original head because they are line bored to that specific head. Cams are all the same size.

 

[Diplomat]

Buy a new/used head and sell the one you have on eBay or something. Let someone else deal with it. Either that or get the sucker align honed. Don't take chances with stuff like this on a motor build. Especially on a vehicle that you know is going to see severe duty.

You can pay now or you can pay later.

 

[1fast97gsx]

yea but if you drop the cams in and the clearances are ok then why worry?

 

[chris90gsx]

im following on what you guys are saying about how it is a bad idea for switching Cam caps, But what about switching Cams themselves??? wouldnt that be kinda the same thing???

I want to know the answer to this question as well. Ok so you keep the original cam caps with the original head. I will not argue against that and that is good practice. But here is where my problem lays. You have stock cams in a head that has say 100k miles. So the cam journal bores (half of it on the head and the other half in the cam cap) have been wearing down for 100k miles. You then decide to put a set of brand new cams in the head without doing any machine work (this has been done by countless individuals and I myself have done it as well). You now have 100k miles worth of wear in the cam journal bores and you decide to put a brand new set of cams in. Wouldn't the journals be distorted slightly and worn needing machine work for a brand new set of cams? I guess it is similar to the main bores when doing a block rebuild. Would you put a brand new crankshaft in your block without align honing/line boring the main journals?? Granted we're talking about greater force loads and heat intensities at the crank compared to the cams, but I know I wouldn't. Someone with good machining background and engine rebuild experience please elaborate on this.

 

[Dallas J]

Think of it this way. Is youre stock cam out of spec? If it has half the wear that the cap has then by your theory a old stock cam should be all wobbly in the head .J/K

A new cam would take that journal back to stock spec and bring the actual gap between the cam and bearing back closer to factory spec. That is if their were wear in it. On a good engine with good oil pressure you should have any wear. I bet it doesnt change .001 after 100k on a good motor, but thats just speculation.

-Dallas J

 

[pboglio]

The journals are made of aluminum obviously. The cams are some kind of hardened steel alloy. I can believe a good amount of wear on the journal, I had a few gouges when replacing the cams. The stock cams on the other hand looked unblemished. When I pulled my stockers off I mic'd it, I don't think I could even measure .001" from factory spec. The journal bearing surface on the head had some pretty deep scratches on one journal, the others looked real good. I didn't bother measuring the journal internal diameter with the caps torqued back on minus the cams. With the oil film all over the cam and journal bearing, it was a snug fit, thanks to prelubing the journal bearing surface. I'm not too worried about journal bearing wear, even on my 100,000 mile motor. I would think the hydrodynamic oil film will take up the gap to a certain extent as long as the journal is fairly round. I'm not losing sleep over it.

 

[bastarddsm]

It's not the diameter of the hole that were talking about here it is the two halves of the holes lining up with each other.

 

[pboglio]

I was responding to chris90gsx's last post, which referred to wear on the original journal bearing surfaces and swapping to different cams. I wasn't responding to swapping different cam journal caps. The factory casts sequenced numbers on them for a reason, that I already know. If the journal bearing caps were co-axial from the factory, more than likely they will still be that way after 100,000 miles, unless the head warped. I'd also expect any new cams to have co-axial journal bearing surfaces as well. A little increase in gap within tolerance might allow for more of an oil film thickness, maybe not a bad thing, especially with some guys running stiffer valve springs.

 

[gsxitement]

what the hell are the numbers on the cap?...is there any way to locate cam caps from the head you have if they got all mixed up while you were moving a long distance with other caps from other heads. the number on the cap i'm refering to is not the location code i.e.: I-1 through I-5 and likewise for exhaust. i'm talking about the number just below that.
i've noticed the number on the cap that varies with different caps of the same location code. can that tell you what head the caps belong to?. just a question. i have many heads, and all the caps got mixed up when i moved back to new york. i've been plying with caps with the head i decided to use. the cams were locked when i first installed them, but i've managed to get the exhaust cam to spin well. i still need to find an e-5 that will work. theres no excessive runout that i've found. any info would help. thanks.

 

[1fast97gsx]

so if need be ... if one were to put the non original caps on 1 by 1 and see if the cam spins freely and if its too loose and it all feels fine then one could swap the caps? Or is a line hone still neccesary at that point? How long are we talking before we see engine failure .... will this happen 500 miles down the road or 80000 miles down the road?

 

[pboglio]

so if need be ... if one were to put the non original caps on 1 by 1 and see if the cam spins freely and if its too loose and it all feels fine then one could swap the caps? Or is a line hone still neccesary at that point? How long are we talking before we see engine failure .... will this happen 500 miles down the road or 80000 miles down the road?

I'm not sure you would get engine failure from a slightly sloppy bearing cap, especially if its one of the interior ones. You've still got 5 other caps supporting the semi-vertical thrust loads. Now running a tight cap is another story. Oops sorry, thought you meant running just ONE non-original bearing cap.

 

[Defiant]

im following on what you guys are saying about how it is a bad idea for switching Cam caps, But what about switching Cams themselves??? wouldnt that be kinda the same thing??? Or are cam caps machined a little different then the cams themselves??? I have 3 6 bolt heads lying around and i was thinking about switching the Cams over to another head because they are brand new. is this a good idea of i use the original cam caps to that head????

The cams are dead straight, aren't they. So are the head and its original caps, because the caps were cast, the head was cast, the seating point of the caps were faced and the cap locations on the head was faced. Then the caps were bolted onto the head, and the cam bearings surfaces were cut. Right where they're supposed to be. Specific to the head itself. Lined up all nice and straight. So long as they're not separated from their original home on the head, you're fine for the life of the car. When you swap cams, the bearing surfaces on the cams are made to fit the head specs. But you're putting the caps back where they came from.

Other caps were cut to fit their native head. They probably won't line up with one another on a different head.

I don't see how this isn't obvious to you guys.

 

[rebuilt65]

The cams are dead straight, aren't they. So are the head and its original caps, because the caps were cast, the head was cast, the seating point of the caps were faced and the cap locations on the head was faced. Then the caps were bolted onto the head, and the cam bearings surfaces were cut. Right where they're supposed to be. Specific to the head itself. Lined up all nice and straight. So long as they're not separated from their original home on the head, you're fine for the life of the car. When you swap cams, the bearing surfaces on the cams are made to fit the head specs. But you're putting the caps back where they came from.

Other caps were cut to fit their native head. They probably won't line up with one another on a different head.

I don't see how this isn't obvious to you guys.

CORRECT!!!!!!!!!!!!!!

 

[Tallen]

The cams are dead straight, aren't they. So are the head and its original caps, because the caps were cast, the head was cast, the seating point of the caps were faced and the cap locations on the head was faced. Then the caps were bolted onto the head, and the cam bearings surfaces were cut. Right where they're supposed to be. Specific to the head itself. Lined up all nice and straight. So long as they're not separated from their original home on the head, you're fine for the life of the car. When you swap cams, the bearing surfaces on the cams are made to fit the head specs. But you're putting the caps back where they came from.

Other caps were cut to fit their native head. They probably won't line up with one another on a different head.

I don't see how this isn't obvious to you guys.

Dammit, I was going to be the first one to input a logical post, but no!
Anyway, the man is correct.

 

[gsxitement]

i totally understand the whole cam caps are mated with their head thing, i'm totally with that. and i wish they hadn't gotten mixed up but they have. what about this. i know this sounds bad but just think about it first. go cap by cap, seeing which ones are tight and which ones work, and the ones that are tight, try and and clean them up. now i'm not saying i'm condoning this, but i had this idea of putting on very fine valve lapping compound on the caps that are tight, spin the cam while slowly tightening down the cap. now, i know that that sounds pretty bad, but if you had the oil galley plugs out and were able to clean out the galleys well, couldn't that work? just an idea....albeit a very bad sounding one, but is it possible?

 

[1fast97gsx]

i totally understand the whole cam caps are mated with their head thing, i'm totally with that. and i wish they hadn't gotten mixed up but they have. what about this. i know this sounds bad but just think about it first. go cap by cap, seeing which ones are tight and which ones work, and the ones that are tight, try and and clean them up. now i'm not saying i'm condoning this, but i had this idea of putting on very fine valve lapping compound on the caps that are tight, spin the cam while slowly tightening down the cap. now, i know that that sounds pretty bad, but if you had the oil galley plugs out and were able to clean out the galleys well, couldn't that work? just an idea....albeit a very bad sounding one, but is it possible?

yup that's what I was told to do as well. I know getting a head with matched caps is a better way to do it ... but this may also work.

 

[Defiant]

i know this sounds bad but just think about it first. go cap by cap, seeing which ones are tight and which ones work, and the ones that are tight, try and and clean them up. now i'm not saying i'm condoning this, but i had this idea of putting on very fine valve lapping compound on the caps that are tight, spin the cam while slowly tightening down the cap.

Two things: MY GOD, IS YOUR TIME WORTH ANYTHING? DSM heads are cheap. They're giveaway. If you don't make enough to buy two of them in the amount of time you'd fiddle-de-dick away by doing this, then you shouldn't own a car because you can't afford gasoline.

But the MAIN thing is that it's not a matter of "tightness". It's ALIGNMENT. Those bores have to be straight with one another within thousandths of an inch, all the way down the head.

I just hope you don't hear about using sand through the intake to polish the manifolds.

 

[1fast97gsx]

I just hope you don't hear about using sand through the intake to polish the manifolds.

What?!?! That doesn't work????

 

[Jake_16_1999]

I just hope you don't hear about using sand through the intake to polish the manifolds.

Straight up Hilarious. Some people in this world scare me with the fact that they are willing to go great lengths in the wrong direction, when all signs point the other way.

Jake

 

[bastarddsm]

they really used to do shit like that. backin the 50's they'd take a handful of ricehulls and throw it down the carburator at 6500rpm, to clean the carbon deposits off of everything. unfourtunatly they ended up getting every valve in it stuck open.

 

[gsxitement]

listen, i understand that doesn't sound good, but it was just a question. thats why these forums are here to ask and learn. i since bought new cams of the hks variety and i am going to get the head line bored. the whole reason i'm going through this madness is because i just spent a long time doing the head i have. so while i would like to go the route thats easiest, as i'm sure most everyone would like to do, i have to go the harder way. so while i understand the outlandish absurdity that my previous statement made, it was just in an attempt to figure out as much as i can. i've been working on cars a long time, and i love working on dsm's and being a part of the community. it seemed feasible at the time, thats why i asked.

 

[Defiant]

That's okay, so long as the message got through to you. Unlikely as it may seem, some think I'm harsh. Best to ignore me, and make sure I don't miss any feedings.

 

[RedBird]

All I have to say is if any of you on this chat board must get on here to ask a question on how to put something together or rebuild anything on your car YOU should not be doing it. Two guys brought their cars through my shop yesterday wanting me to show them how to put new clutches/flywheels in and they had never done anything other than an oil change before. Anyways where I'm going with this is they still screwed things up even when I tried to go through it with them step by step. I ended up going behind them and fixing their errors. If your not a trained mechanic I'll bet you get in deeper than you want to be and end up spending more time and money than if you just took your car to a shop to begin with. Sorry for the long post guys but some of the questions I see on here baffle me and many of you people should not be working on cars

 

[gsxitement]

i like this board too much to reply to that nonsense