bad cam shaft, pictures of damage

[oren hughbanks]

So I have been battling alot of valve train noise lately. Finally cracked into it today and see what's going on and noticed the end of the intake cam looked a little funny, and discolored. Popped off all my cam caps and found this.

I attribute the carnage to be from a bent cam, probably warped from being over heated. I bought the head used, but was immaculate, cleaned and recut from machine shop. Never had been run, still had the assembly lube in it. Sure wouldn't mind finding the guy who had sold it to me and taking that cam shaft to him, but it's my fault too for not checking the cam journal surfaces when I bought it.

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[GST with PSI]

Before you do anything, establish what your goals for the car are. Forged internals are great if you plan to push the car past the limits of the stock bottom end. But, if you'd be happy with 400 hp give or take, a stock bottom end will gladly get you to where you want to be.

The point here being, build toward your goals, not toward pipe dreams. 400 hp doesn't sound like much, but it's a much harder number to attain than people realize. I'm definitely not knocking what 911 is saying, but things like budget, time, and overall knowledge of the platform should all be taken into account when deciding on a build. The biggest failure I typically see with people who start building the 4G63 platform is not being realistic with themselves. It's nice to stack big turbos and nice parts, but making them actually perform on the car is harder than it seems. This is also where knowledge counts, because it takes know-how to make complicated setups actually perform. Not to mention, it takes plenty of cash to build a forged motor.

Lastly, don't kick yourself over the head. If you stick with the DSM platform, I promise you'll spend plenty more money making mistakes and learning in the process. This kind of stuff happens, and you can't let it get you down. You learned a valuable lesson, and the importance of being able to double check the work of others. That's why forums like this are so awesome. If something ever seems off, be sure to use the group of knowledgeable individuals here at your disposal. Good luck.

 

[oren hughbanks]

Thanks bro for your help! And to everyone else, I guess it's a good excuse to build better and faster[DOUBLEPOST=1416274635][/DOUBLEPOST]The original goal of my build was 350 to 400hp. I wanted to strengthen the bottom end weak points, so I went with ARP fasteners for the mains and rods, and acl bearings. I went with the 2g 1g rod combo, they came in my box of parts when I bought the car so that's what I had available, and my budget didn't have any extra cash for forged internals.

Over the last few years I've had my car I've jumped on any chance to get parts on the cheap, and I have a extra block on my stand I've been debating on what to do with. I think my next goal is going to be a Holset build, with all my research I've done that's definitely a good bang for your buck. Where I live in az I have no access to E85. So I'm looking towards maximizing a build to where I can get the most out of pump 91.
I kept my balance shafts this time, but on my next build I'm planning on eliminating them. Mainly for this next build I want it to be as versatile as It can. Having no E85 really puts a cramp in my plans

 

[tmoney20g]

You went with ARP mains, did you have the block align-honed ? and was the block bored/honed with a torque plate ?

 

[GST with PSI]

That's really the way to do it for most people. Stack parts, wait for deals and make things work where you can. Going balls out on a build is great and all, it's just not feasible for the average joe. The majority of guys out there don't have a million dollars to spend on a build all at once (myself included).

The 1G rod / 2G piston combo is a proven winner, and is good for 400hp easy if you build and tune properly. You're in a good position since you have a spare block, and hopefully you can build slowly over time and reach your goals as time and budget allow.

Find a reputable machine shop to do your machine work. Sadly, this is one area where you can't really cut costs. You pay for experience and quality with a good machinist. However, knowing what your goals are can save you some cash by building a motor that supports your goals without going overboard. A forged motor properly balanced and blueprinted will run you far more than a stock-ish rebuild. Know what you want BEFORE you walk into the door of the machine shop. Establish a budget with the shop, and get all estimates up front. Make sure the shop notifies you anytime they need to go outside of the agreed upon budget, and get your approval before proceeding beyond it. Although some situations legitimately warrant it, I would try to avoid deposits and paying up front before your work is done when possible. A reputable machine shop typically won't bill you until after they have completed their work.

Look around, and you'll find tons of horror stories where machine shops go way above a customer's budget. Typically, the customer forfeits their parts after not being able to pick up the tab...Of course by this point, the customer probably has a substantial amount of money invested...All of which is also lost in the end.

Be smart, build toward realistic goals, and stay within your budget and you can't go wrong.

 

[Lou98GSX]

I would think that if the cam caps were on wrong you would not be able to turn the motor by hand . don't know if he even tried first to turn the motor by hand before starting it.

 

[911gdsmboostin]

That's really the way to do it for most people. Stack parts, wait for deals and make things work where you can. Going balls out on a build is great and all, it's just not feasible for the average joe. The majority of guys out there don't have a million dollars to spend on a build all at once (myself included).

The 1G rod / 2G piston combo is a proven winner, and is good for 400hp easy if you build and tune properly. You're in a good position since you have a spare block, and hopefully you can build slowly over time and reach your goals as time and budget allow.

Find a reputable machine shop to do your machine work. Sadly, this is one area where you can't really cut costs. You pay for experience and quality with a good machinist. However, knowing what your goals are can save you some cash by building a motor that supports your goals without going overboard. A forged motor properly balanced and blueprinted will run you far more than a stock-ish rebuild. Know what you want BEFORE you walk into the door of the machine shop. Establish a budget with the shop, and get all estimates up front. Make sure the shop notifies you anytime they need to go outside of the agreed upon budget, and get your approval before proceeding beyond it. Although some situations legitimately warrant it, I would try to avoid deposits and paying up front before your work is done when possible. A reputable machine shop typically won't bill you until after they have completed their work.

Look around, and you'll find tons of horror stories where machine shops go way above a customer's budget. Typically, the customer forfeits their parts after not being able to pick up the tab...Of course by this point, the customer probably has a substantial amount of money invested...All of which is also lost in the end.

Be smart, build toward realistic goals, and stay within your budget and you can't go wrong.

To add and disagree a tiny bit workin in a reputable machine shop we don cut corners and we do good wrk think about this though a lot of good machine shops (quality work not quantity ) will always look or your best interest even if you can't see it your self we will talk customers down a road that may seem more thn you need but is usually for your protection if you set your eyes a little high reasons being is to make sure te motor doesn't blow and you blame us if you say your building a moor for 350-400 and years later put big turbo big injectors and start turbo the boost up and so on te motor fails due to parts that Wernt ment for it and you look at us that we built te motor or we did th work and it blew due to insufficient oiling we machines it but you change things this is why we dot typicly warren tie motors unless we build and dyno them and if you change anythig like time it way up and use e85 and fry rings in on you but we will typicly help you eing you brough the work to us.. This part is regular ding the quote te reason good machine shops are smaller is exaist we take our time and make 5 jobs right eater then take 10 jobs an rush hast is waste and a note on the deposite we take them yes look at our point of view we have many people stoped by dropped parts and block off say yeah go ahea and can't pay for it mean while we did the work an have no money for it keep in mind you have to pay employees lights electric taxes and so on and ibdono bout ou a lot of shops don hve hundreds laying around to pay for you work an pay for you earrings and do it for 5 jobs think about it you take 5 jobs takes 4-6 weeks to do them all you didn take any deposits how do you pay your guys tey did te work used the electric you gotta pay insurance it's cold out te gas bill will go up so these are some reasons business owners have to think about plus if you drop a block and head for work we do some work and find out the block was cracked crank is useless and te head is junk we did te work and you don't pick up the phone now an we lost out on a few hundred dollars now I'm not saying anyone ere is that kind I person but I am telling you these are the people that ruined it for everyone else the reaps we take deposits is so we know you are seirous and it pays for some f the work start you own machine shop and try runnin it any other way my father has been in business for over 30 years and this is the reason we still are in business how this helps you understand why a little bit or atleast gives you a better respective or another poin of view some shops are bad shops but some of use are good an we take our rep. Very seriously. And our business too do goo work and work will come to you. If you are anywhere I'm the western pa area you can always look us up

 

[GST with PSI]

I'm sorry, but I can't understand half of what you wrote. Your paragraph is difficult to follow. I believe I get what you're trying to say, though. I suppose we'll just have to agree to disagree.

I emphasized building toward a goal specifically to avoid over spending and over building. If you have the budget to build for "what if", then that's awesome. Go balls out, like I said. For the rest of us, realizing your end goals will allow you to stay within your budget while still getting your car to where you want it. In my experience, a reputable shop will quote you for work to be performed, and nothing more. The multiple machine shops I've dealt with didn't inflate estimates to cover things that might come up. That's crappy business practice in my opinion, and personally, I avoid places exactly like you are describing.

I've paid in advance for the machine shop to order parts on my behalf, such as rings, bearings, and other internals. However, I've never had to pay for work that hadn't already been completed, and I never would.

Sure, if I had a good working relationship with a shop, or some previous history to feel comfortable about putting money up front, I may agree to a deposit or something. But, I would never walk into a shop off the street and pay in advance or put down a deposit for work that had yet to be completed.

I'm sure that's how some places operate, but that's not how I operate. Nor has it been my experience in dealing with multiple shops; ranging from single man operations to bigger chain shops.

As far as doing quality work, that's easy for someone who know's what they are asking for. For those of us who farm out machine work and tackle assembly and such ourselves, there's no question weather or not the machine shop did things correctly. I break out my T-gauges and micrometers, and double check all the work that is done.

However, for someone who is relying on the machine shop to deliver a finished and assembled product, double checking that work that's been done can be a bit more difficult. It's usually not until after a failure and careful disassembly that the cause is found. At that point, it can be anyone's fault.

To me, it all comes down to dealing with a reputable machine shop/builder. I expressed some of the things I personally look for in a machine shop; views which may not be shared by everyone who reads this. That's cool, but I've yet to receive a sh|tty motor in all my dealings, so I'd like to think what I'm suggesting works.

 

[911gdsmboostin]

Sorry for the botched typing my iPhone and big thumbs don't always agree. Also I am gonna have to say your right we shall agree to disagree.. I'm glad your way has worked for you and our way has worked for us their prob is some Mis communications and Mis understanding of what is ment but either way this isn't a place to bost opinions its a forum for info but best of luck to the poor guy who is recovering from the carnage

 

[oren hughbanks]

Oh man it's a whole other discussion about my machine shop experience.

I called every machine shop in our area and none of them do any type of engine work. So the one shop in town that did , ended up taking 4 weeks longer than what they said. They were nice, and did a semi quality job. But dropped the ball on my crankshaft. I thought it could be repolished, but it ended up needing to be 're cut. So that took another week since he Dosent do that in house, and when they go assemble my short block, he forgot to tell me that I need oversized bearings now. So I paid next day air shipping on them, to get my block done by that weekend. I go to pick it up, and he Dosent have my main studs installed, said I gave him head bolts, not main studs. Well it says right on the side of the box, MAIN STUDS, on a brand new sealed box! So I did that myself when I got it home and back on the stand .

No I did not have it line bored or torque plate honed. I asked them over the phone and he said it wasn't entirely necessary. That he has good luck on other builds not getting that done.

I had turned the engine over by hand multiple times when I set the timing, and never noticed any binding on the valve train. So far my block has been holding up great, no problems there, but the cylinder was a mistake[DOUBLEPOST=1416316609][/DOUBLEPOST]The machine shop that did my work was a disaster zone, and I'm with everyone on here my money is important, and that shop better look a doctor office and better be spotless, but he had new equipment, and got excellent review's, so I can't give him a horrible review.

 

[GST with PSI]

Sorry for the botched typing my iPhone and big thumbs don't always agree. Also I am gonna have to say your right we shall agree to disagree.. I'm glad your way has worked for you and our way has worked for us their prob is some Mis communications and Mis understanding of what is ment but either way this isn't a place to bost opinions its a forum for info but best of luck to the poor guy who is recovering from the carnage

No worries. I can absolutely understand your point of view, and I'm definitely not suggesting your shop isn't good at what they do. I'm just expressing my personal views on the matter, which I should note, are completely from a customer standpoint. I have no idea what it takes to run a successful machine shop, so I take what you're saying as fact for your own business' situation.

Regardless, I also hope the OP gets up and running soon.

 

[911gdsmboostin]

I don't care what anymachinest tells you if you want an engine straight it starts by straighting the one part that every other measurement is taken from the centerline of the crank... Any Proformance engine an some not is almost always line jones line bore is much more intense and usually my needed unless installing billet main caps or if you and spun a crank bearing but line honed decked and torque plate home is always a better way and then you know the block is straight at allthe important parts and I gotta agree doesn't sound like a good shop kinda sloppy and forgetful not a good combo what's that say about everything else they do if their that I'll minded not to notice that they are main studs what else would thy forget... It does take a lot to run a shop but a lot f that is knowing what to do how to do it an how to preform to a customers liking billboards and reviews online don't make good machine shops an deffantly not new machines reputation word of mouth some I our machine are from the 1950-1960 still work great and do a great job jut as good as new machines just takes a little knowlage and experience from the guy running it

 

[oren hughbanks]

Yeah it's getting put back together, then parked again till I can resource a new head from somewhere

 

[lasthope05]

I don't care what anymachinest tells you if you want an engine straight it starts by straighting the one part that every other measurement is taken from the centerline of the crank... Any Proformance engine an some not is almost always line jones line bore is much more intense and usually my needed unless installing billet main caps or if you and spun a crank bearing but line honed decked and torque plate home is always a better way and then you know the block is straight at allthe important parts and I gotta agree doesn't sound like a good shop kinda sloppy and forgetful not a good combo what's that say about everything else they do if their that I'll minded not to notice that they are main studs what else would thy forget... It does take a lot to run a shop but a lot f that is knowing what to do how to do it an how to preform to a customers liking billboards and reviews online don't make good machine shops an deffantly not new machines reputation word of mouth some I our machine are from the 1950-1960 still work great and do a great job jut as good as new machines just takes a little knowlage and experience from the guy running it

My advice for you is. If you wish to be heard and for people to take you seriously, you need to start using proper grammer and punctuation.

Not only is it a rule of the forums, but nobody want to read essays that are diffecult to read and confusing run on sentences. Personally, I stopped reading after a few lines because I didnt know what you were trying to say. This goes for your other post above too. Not trying to be a forum police, but it helps others coming in looking for clear answers and solutions to simliar problems.

 

[briansmith]

The machine shop I use only does heavy equipment work. Tow boats trains and such. When I first started using them I showed up. Didn't call. Talked with the shop management told them what I was needing. I always provide them with a nice typed up paper in a clear protective cover of all the work I need performed I include all torque specs clearances I want to achieve a good list of base numbers of measurements that I have taken with the mics I own and spaces for them to write down there measurements that they return when I pick up the product and for this reason they have no problems doing work for me u rly can't expect a machine shop to know everything about ur engine unless the only specialize in it as a builder it's ur responsibility to provide them with all the necessary information on fasteners and there torque specs prior to the work and to double check that work is done correctly. All the information should go into a binder for later reference if a problem up rises and it's always good to have all the specs if u later decided to resale u have good proof of the work done inside the engine and not the ohh I've had this and this and this done only to buy it and find out later the seller out right lied about it. Personally I never take anyone's word when buying a engine. I just assume it's either stock or been assemble incorrectly and that's my bargaining chip for getting it at the low price. But if some one showed my information like I keep on all my builds and could coherently talk to me about the specs I would have no problem with paying a reasonable asking price. This may not seem like a good thing but we learn from the mistakes we make. And I have made a few . And I'm sure u will learn from this one.

 

[oren hughbanks]

Wow that's some good information to know. I will be going with a different shop for my next engine build. I would like to do all the assembly myself this time , I really want to learn my engine and my 4g platform, and not make another mistake. Lesson learned this time for sure

 

[donniekak]

1 of 2 things happened here, the first has been discussed, possible cam cap mix up.

The 2nd possibility doesn't get much attention.

When a head warps, the whole head warps. If you take a warped head on a bench and check the cam bores, they are not in alignment. If you bolt the head down with enough force, the head flexes, and the bores come closer to alignment. If you just cut the high spot off the deck surface of a warped head, and bolt it on a block, the cam bores will be way out of line. This is why it's a good idea to check the cam journal to cam bore oil clearance on used heads with them bolted to a block. Even just checking for easy rotation of the cams with no rockers installed, when bolted to a block is better than slapping it together and hoping.

 

[oren hughbanks]

Here's some pics of the head before I installed it

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[bmxfelon420]

Not all main bores distort when you use ARP fasteners. You NEED to torque them down and have them checked to make sure first, but on my build they were round with the ARP studs. I have another friend who did as well. So it's not always a certainty that you will need to bore them, but they do need to be checked to verify they are round.

 

[oren hughbanks]

When I installed my main studs, I spun the rotating assembly countless times to check for binding. It was the original block when I took it out. Had 167k on the clock. None of the bearings has spun or anything but there was some scoring on my crank. Everything thing was torqued down per ARP specs, I used their fastener lube, and I invested in a good quality torque wrench. I'm sure it's not perfect, but it's what I had to work with in my budget. The shop I went through did not offer line boring services.

One thing I thought was a little odd with my cylinder head, was that it was painted. Painted silver, on the sides. I figured that that it was just for looks. I prefer any shop to paint the sides of it. Atleast if they did that, I know it wasn't media blasted, filling up all the oil passages with sand. They painted right over all the little hex head plugs, which now that I look back I should have pulled them all out and hit them with compressed air, to blow out any remaining metal chips.

But why were only two of the cam bearing surfaces destroyed? Why not more? If the head was still warped from before, wouldn't more be destroyed??

And for my replacement head, should I find one at the salvage yard that's all original? That way I know it will be the original cam caps?

 

[briansmith]

Yes a head is no good without matching caps only way to swap cam caps is the have the head line bored just like u would do the block doing this might add a slightly larger oil clearance for the cam journals but oil will fill that in I highly doubt the whole head was warped from what u stated earlier most likely caps where flipped. Given a decked head I'm sure a shallower tear drop did not help the situation if u didn't grind it out prior to install when u install a new head double check the caps are in the proper position faced the right was. All dowel pins are there and use ample assy lube on each journal both cam lower. Cap and cam itself make sure to grind out the tear drop a bit. Even on a Un decked head. Top end will like a little more oil. Clean and inspect the head remove all plugs. Carb clean and blow them out if the bearings surfaces are a hair bit ruff. Use a cross buffing kit like for port and polish work with a bit of wd40 as a lube. Run the cross buffer in and out of the bearing surface in a horizontal motion to mimic the cam. This will polish up the surface and take high spots out of the face. Low spots r ok. They will fill in with oil highs will eat the cam and migrate all around the bearing face and that's a big no no I have fixed many heads with oil starved cam bores and it's always worked wonders if u really wand to make it slick mothers chrome polish and a wool buff cone will bring it up. Just make sure u clean up afterwards rinse the head with brake carb or mineral spirits I do all of my own my head work port polish of runners and combustion chambers bearing surfaces deburring oil return port cleaning and tear drop mods

 

[keltalon]

Op do you have a picture of the complete head on the cam side with the cams removed after damage? I am interested in what the other cam journals look like. Just curious

 

[oren hughbanks]

I don't have a pic, but they all looked perfect, smooth as could be, like they were just cut