ok, so i am in the proccess of rebuilding a 4.5 liter for my 87' seville. i have the block clearded out, including the camshaft. when i pull the cam, i look it over to inspect it for wear. i find some pitting on 3 of the lobes, and the pitting is pretty noticable. i know now that i have to replace the cam. thing is, i have not had to replace a cam from one of these motors for over 2 years, so i know things will be a little harder to find. imagine my suprise when i am told by just about every auto store that the cams from all 4.x series engines have been discontinued! there are only 2 places in town that i can get one, and they arent cheap. the local dealership has them, and a rebuilder supply shop does too. the prices range from $275 (shop) to $400 (dealer), all without matching lifter kits. the lifters require an extra $180! needless to say, the block still needs cleaned and new cam bearings pressed in.

i seem to have exhausted my resources, including a few places online for a cam. i am wondering if anyone here knows where i can find a new camshaft for a 4.5 liter engine. and for a decent price. any links or info would be greatly appreciated. thanks, illuminaP :cool:.

not a good sign that there discontiueing parts for these engines

what about craine cams ? seems like i heard they can make one off cams from cores

luckily the delvac oil has quited my valve train down enough for me to not think about it so much (im a little paranoid of pushrod engines)

BTW do your service manuals say anything about redoing valve lash at certian intervals in the engine's life ? ie 75k 125k or whatever ?

crane cams will do a regrind, though expensive. when i redo my 4.9, i will call them up and see if they can do something for me.

as far as the valve lash, i think we don't have to worry about our engines, they are hydraulic self-adjusting lifters.

thats what i thought on the lash deal , just wanted to make sure ........

Maybe i should just say "Damit its running fine dont touch it" .....if i wasnt such a stickler for preventive maint......

are you having some valve train noise?

yeah, i'm a stickler too. i could re-use that cam, but the pitting though just does'nt cut it with me. every machine shop i have talked to told me it needs replaced without even seeing the cam: i was considering a re-grind.

i know one more place to talk to, and i am taking the cam in so they can see it first hand.

here, this is the problem. can you see it? badcam2.jpg

just took the old cam to the shop, they said it cannot be fixed for cheap. so i ordered a new camshaft kit. thing is though, the supply store i got it from said it "might" not be availiable too!

i have worked on quite a few engines, including many 4.x engines, and this is the first time i have ran into these problems. however, the last time i had to replace a cam was over 2 years ago.

Which cam are you using?? The flat tappet cam from the 87 or the roller cam from the 4.5??? The picture looks like the roller cam. If so, it is fine. I have never seen a lobe fail on a roller cam. The roller cams get that "micro-spalled" look from the roller rolling over them and they stay that way for several hundred thousand miles. Forget replacing it. Waste of time and money. The micro-spalling happens relatively quickly during the early life of the cam and then the micro-spalling actually seems to aid in lubrication retention at the roller/lobe interface and the micro-spalling stabilizes and stops and stays the same forever.

The re-man engines that GM contracts for actually re-use the roller cams from the cores coming in from the field. We looked at the core engine cams and they were so good that they passed re-validation tests as new. The reman 4.5 and 4.9 engines with roller cams get the cams cleaned and inspected. The lobes are polished with crocus cloth and the distributor gears are burnished with a brass bristled wire brush and they are cleaned and reused. The steel roller cams are hardened and will run forever unless a lifter fails or turns sideways and totally destroys a lobe. You cannot wear one out in your lifetime. This is the only re-man engine situation that I have ever heard of that allows re-use of the old cams !!!! They are that good.

pics small but she doesnt look very good there does she ?

noise is gone now with the delvac but before it sounded almost like i had a lazy lifter , i imagiune the beatter oil pressure with the delvacs heavier weight helped that lifter . Also must have imporved lift as it runs beatter . probably the first time ive seen an engine run beatter by chengeing the weight and type of oil used

BTW....the roller lifters are equally bulletproof. Inspect them carefully and make sure the axles are still tight in the lifter body. The only reason I would replace a lifter would be for a loose axle....something that randomly and rarely happens with a lot of miles. Otherwise, they are fine.

geezus bbob! you may save me money yet :worship:. i sure hope everything goes fine with the cam. i will just cancell the order i made this morning and get my cash back. i spent $465.00 for the new cam. i'll just tell them i found a "cheaper" deal.

i forgot bbob, yes, that is a roller from an 88' 4.5 liter. the only concern i had was the roughness of the spalling or whatever it is called. it is'nt that bad, but i figured i needed to replace the cam. it's not like i can stick my finger through the thing, just a little gritty or whatever. but if you say it is normal, then i will take your word for it. i just hope the turbocharger i plan on installing soon after the rebuild won't kill it :lildevil: .

Unless a lifter guide falls off and/or a lifter turns sideways or something there is practically no way you can kill the roller cam. Like I said, the re-man guys recover the roller cams from the field return core engines and reuse them. The highest recovery rate of any part in the core engines is the roller cams. Almost all of them are OK. The reman facilities actually have a "surplus" of roller cams as they recover far more than they need for re-man engines..... That may be the reason that there is some difficulty in servicing them. The "new part" service manufacturing was moved to an independent facility using the original tooling. The assumption was that service volumes would continue for reman as reman engines typically get new cams based on past experience but the roller cams changed that idea. The service requirements for roller cams in the field was practically zero. I mean like none were required. And with reman engines using the used cams from core engines there is very little to no volume required for service from that tooling so it may have been shut down permanently....

The only thing that can usually be hurt at all on the roller cam is the distributor gear. If it is scored or worn at all the rest of the cam is junk, unfortunately. Fortunately the distributor gear on the roller cams appears just about as bulletproof as the lobes.

Clean the distributor gear on the cam carefully and check the wear pattern. It should be just a small, polished pattern that is uniform on each tooth around the cam. If you are rebuilding the same engine I would recommend a new distributor gear on the distributor. Install it with lots of moly prelube on the gear teeth, use the EOS as break in lube in the oil and keep the RPM down below 3000 for the first 15 or 20 minutes to keep the oil pump load low and allow the distributor gear to break in and burnish. That is really the only critical area in the pushrod engine for break in ....keeping the distributor gear load low (since it drives the oil pump too) by keeping the RPM down for awhile.

If you look at the cam carefully you will see that the #5 bearing journal and the distributor gear itself is actually made of cast iron while the cam itself is steel. The lobes of the cam are case hardened...check an edge of a lobe with a file and see how hard the surface of the lobe is. Each lobe was individually hardened via an induction hardening technique. The rear of the cam was turned down and a cast iron "nub" was pressed on for the distributor gear blank and the #5 journal as a result. The distributor gear likes to be cast iron for wear so the extra step was taken to press on that cast iron section just for the gear to enable long life of the cam. That is why I am so sure that it is OK. If you look carefully you can even see in the picture were the cast iron section is pressed on as there is an un-even spot on the base of the cam shaft itself immediately beside the distributor gear. A lot of care and engineering went into that cam .... if I say so myself..... LOL.

Don't ask how I know so much about it...LOL LOL

cool. i just hope the supply shop gives me back my cash, so i can purchase the rings and main/rod bearings and such. i think they will however, being that it was on some sort of back-order.

needless to say, i still have to have the block cleaned and such. i'll be having some fun :D.

Don't hot tank the block or anything. I would just wash it and leave it alone. Unless the cam bearings are really worn or scored I would not replace them. The lifter carrier that forms part of the cam bearing bore cannot be removed without distorting the main bearings so I wouldn't remove it or even remove the cam bearings. Most cam bearings are fine anyway except when people ruin them by hot tanking a block...and you don't want to hot tank an aluminum block anyway. Usually those engines just need to be dissassembled, cleaned thoroughly and reassembled with new bearings and rings. If the hone pattern is still in the bores leave them alone. Just replace the rings. Pistons are likely fine, especially if the turning pattern on the skirts is still visible. Remember to get the OEM main bearings and get the front main for the main bearing thump fix (slightly tighter clearance...use ONLY on the front main). Get the intake OEM reseal kit for the intake that includes the spring loaded bolts for the intake. The 88 did not have that yet I don't think....wait...maybe it did. If you have the spring loaded bolts on the intake (the stack of belleville washers) then that is what you want.

The only thing that can usually be hurt at all on the roller cam is the distributor gear. If it is scored or worn at all the rest of the cam is junk, unfortunately. Fortunately the distributor gear on the roller cams appears just about as bulletproof as the lobes.

Clean the distributor gear on the cam carefully and check the wear pattern. It should be just a small, polished pattern that is uniform on each tooth around the cam. If you are rebuilding the same engine I would recommend a new distributor gear on the distributor. Install it with lots of moly prelube on the gear teeth, use the EOS as break in lube in the oil and keep the RPM down below 3000 for the first 15 or 20 minutes to keep the oil pump load low and allow the distributor gear to break in and burnish. That is really the only critical area in the pushrod engine for break in ....keeping the distributor gear load low (since it drives the oil pump too) by keeping the RPM down for awhile.

If you look at the cam carefully you will see that the #5 bearing journal and the distributor gear itself is actually made of cast iron while the cam itself is steel. The lobes of the cam are case hardened...check an edge of a lobe with a file and see how hard the surface of the lobe is. Each lobe was individually hardened via an induction hardening technique. The rear of the cam was turned down and a cast iron "nub" was pressed on for the distributor gear blank and the #5 journal as a result. The distributor gear likes to be cast iron for wear so the extra step was taken to press on that cast iron section just for the gear to enable long life of the cam. That is why I am so sure that it is OK. If you look carefully you can even see in the picture were the cast iron section is pressed on as there is an un-even spot on the base of the cam shaft itself immediately beside the distributor gear. A lot of care and engineering went into that cam .... if I say so myself..... LOL.

Don't ask how I know so much about it...LOL LOL

i have her in my hands as we speak...looks fine to me. i usually break an engine in for about 1500 miles or so. those people who's engines i have done for them, i tell them to take it easy, but i cannot controll them :eek: .

even the bearing journals seem clean to me. i may have them polish the cam though, and get those cam bearings pressed in while they have the cam.

thanks for the help bbob!!! :cool:

Don't hot tank the block or anything. I would just wash it and leave it alone. Unless the cam bearings are really worn or scored I would not replace them. The lifter carrier that forms part of the cam bearing bore cannot be removed without distorting the main bearings so I wouldn't remove it or even remove the cam bearings. Most cam bearings are fine anyway except when people ruin them by hot tanking a block...and you don't want to hot tank an aluminum block anyway. Usually those engines just need to be dissassembled, cleaned thoroughly and reassembled with new bearings and rings. If the hone pattern is still in the bores leave them alone. Just replace the rings. Pistons are likely fine, especially if the turning pattern on the skirts is still visible. Remember to get the OEM main bearings and get the front main for the main bearing thump fix (slightly tighter clearance...use ONLY on the front main). Get the intake OEM reseal kit for the intake that includes the spring loaded bolts for the intake. The 88 did not have that yet I don't think....wait...maybe it did. If you have the spring loaded bolts on the intake (the stack of belleville washers) then that is what you want.


yeah, i know about the hot-tanking. alluminum is no good for it. good thing i have not removed the cam bearings yet! i cleaned the pistons/ring grooves and such. yanked the liners and am awaiting the new o-rings from cadillac. should be in soon.

i was under the impression though that the bearing "thump" was on the early 4.9's? not too sure about the 4.5's. i have not had any problems from any 4.5's i've done.

thanks again...

PS. time to break the karosene out and have some "fun" cleaning the block...pray for me... :devil:

The thump can show up in any of the transverse 4.x engines. It is due to the pull of the serpentine accessory drive belt. The resulting load on the crank pulley is straight up so that pulls the crank snout up and the firing loads push it down...thump thump thump.... no harm done just noise. It is never heard unless the bearing clearance is a little tiny bit on the loose side. Use the tighter clearance GM service bearing on the front main to avoid.

The thump can show up in any of the transverse 4.x engines. It is due to the pull of the serpentine accessory drive belt. The resulting load on the crank pulley is straight up so that pulls the crank snout up and the firing loads push it down...thump thump thump.... no harm done just noise. It is never heard unless the bearing clearance is a little tiny bit on the loose side. Use the tighter clearance GM service bearing on the front main to avoid.

cool. i am going to order clevite rod bearings though. as i stated before, i have a wild hair up my backside and plan a little turbo for her...
turbocam.jpg i need serious help!

this "thump" does it occur like driving in a tight parklinglot with the engine at operating temp? i get a thump at the time , wondering if it is the thump your talking about . Never surfaces at normal speeds and normal driving , just in parkinglots and slow speeds and is consistant with engine rpm untill i guess oil pressure takes up the slack?

just as long as that thump does'nt lead to this...

badbearings.jpg

illumina
If you plan on adding a turbo charger to your Cadillac Engine don't forget to upgrade and install some new H.P. Stickers under your hood to add to your increased Horsepower rating. :D

Great post by the way bbob :worship:

illumina If you plan on adding a turbo charger to your Cadillac Engine don't forget to upgrade and install some new H.P. Stickers under your hood to add to your increased Horsepower rating. :D

you don't give me much mechanical credit do you?

Been thinking the same thing, turbo on the 4.9L would be awesome.

my concerns are the high compression, and the need for additional fuel under boost.

Might be a time for a new thread....

compression is slightly lower for the 4.5 liter. i think it is around 9:1 or so. even 9.5:1 in the 4.9 liter is ok so as long as you don't go for 50 lbs. of boost or some shit. 6-8 lbs. seems to be a safe bet before you get serious ping or whatever.

i won't have the project underway for a few months, but when i do, i plan on posting a step-by-step instruction manual to the install.

7 psi is fine for even 9.5:1.... worked on sr20de engine fairly well

but we needed to go to larger 370cc (up from 240) injectors to pull it off safely ...440cc allowed for more boost when the turbo pistions and piston coolers were installed

but maybe if we can increase the duty cycle and fuel pressure.... larger injectors wont be needed ?