See this post if you want a more detailed history of what's been going on with my car lately: (Old Post)

I've got a freshly rebuilt L98 engine in my '89 IROC and, basically, it can go from cold to redlining the temp gague (and boiling over) in ~20-25 minutes at idle.

Here's what I've done so far:

- new high-output water pump
- new radiator (with metal tanks and three rows)
- new radiator cap
- new high-flow 180 degree thermostat (from EMP Stewart Components)
- adjusted the valve-lash on all valves with the car running
- changed the coolant
- manually forced the fans to stay on
- adjusted the timing (although it won't really idle with the base timing set to spec)

If I force both fans on, I can get the temp "down" to a little more than 220 degrees, but that's still rediculous for all that I have done. So, we've pretty much tried all of the easy stuff that I can think of and that has been suggested to me. I've talked to several mechanics, and there are currently two theories:

1. The timing chain is not "set" correctly. That is, relative to the crankshaft, the camshaft might not be on the right teeth. I don't know if it helps the argument at all or not, but again, the engine will not idle with the base timing set to +8 deg. At best, we can pull it to ~+10 degrees, where it will idle smoothly--albiet at about 1200 RPM. Also, when it's "idling" like that, if I put the car into gear, it will simply die.

2. We might not have put the intake gaskets correctly. The theory there is that, if one of the gaskets were to be put on backwards in any way, then the coolant channels could be blocked, causing a head to not get any coolant flow.

What do you think? As I see it now, I can choose to either pull all of the intake off (not fun) and check the intake gaskets, or I can pull off the accessories, drop the oil pan (to get the timing cover off), and check the timing chain (also not fun). So, which sounds like the *best* guess for what the problem might be?

As far as having a professional look at it... I'd really love to, but it's not in the budget at all. I'm barely 18 and working two jobs (as well as going to school) just to help pay to get this car on the road. (Sorry if I sound pissed, but that happens when you've spent the last several months and have everything all shiny and put back together, only to have a large driveway paperweight).

As always, I appreciate any help at all...

 

Blow on it?

 

Sancho,

Never mind Xeno. He's just playing with you a bit, trying to lighten it up. I know you're not having any fun with your toy, but here is a rather long thread that relates to your problem:

https://www.thirdgen.org/techbb2/sho...307&perpage=20

Many of the symptoms were the same:

1. Overheating quickly;

2. Lack of power;

3. Lack of good idle;

4. Inability to run at stock timing setting;

5. Valve noise.

What I found was a bent valve (cause still not ascertained) and a timing chain that was installed 18° off (one tooth on the cam sprocket). The valve may have been bent by the piston chasing it to the seat, but there was no evidence of that on the piston head.

The major issue was the late valve timing, which caused low intake vacuum, poor performance, and overheating. Sound familiar?

Anyway, this was what we found:

 

First evidence I've seen that Vader is human.

 

Did you check your fuel pressure? Are you running too lean or too rich? Just a thought.

When I first started my stroker TPI last month the engine would overheat real fast also, and the manifolds were glowing red hot. I adjusted the fuel pressure and now the car barely goes over 180.

 

Hey there guys--thanks for the replies.

Vader: I was hoping sub-consciously when I originally posted that you would reply; I've seen you help many other people on this board and you definately seem to know your stuff.

I've been late to reply to my original message because I've been reading through the post that you linked for me. I'm still reading it (I'm a very slow reader ). I'm not ruling that out the possibility that I could be in the same boat as ChevyKen. I will say that when I was putting the new timing chain on, I was disappointed with the amount of "slack/play" in it--it had about as much "slack" as the old chain with 160K miles. It was enough slack that I wasn't completely confident that I had put it on correctly. I posted about that before I dropped the engine in a few months ago, and the replies I got simply suggested that the chain was supposed to be like that as it was "pre-stretched" at the factory to reduce chain stretch in the future. I think I might have the video(s) of my dad moving it with his hand to show how much slack the new chain really had; I'll post them if I can find them.

However, we're going to go ahead and pull the intake mainfold off tomorrow just to make completely sure that we didn't screw up the intake manifold gaskets and that we are not blocking any coolant ducts. We're just going to check it so that we can rule it out, and if it turns out that that wasn't it, then we're going to go ahead and pursue the idea that our timing chain is off. At least this way, we don't have to go breaking our fresh/new seals around the oil pan and timing cover when we're not 100% sure that's what it is.

I'm continuing to read the post though--I'm still at the point where I'm waiting for you all to figure out that it's the timing chain.

felo72: I have not checked my fuel pressure, but I need to. Assuiming that I can get money for a FP gague, that will go near the top of the "TO-DO" list. I will say that the exhaust smells rich--but, then again, the exhaust on my V6 Camaro smells very rich as well, and it's my daily driver (I put ~250 miles a week on it, and it's pretty reliable). Thanks for the suggestion.

I will keep you posted--expect a reply Sunday (hopefully) after I finish tearing down and putting the intake back together...

 

Okay, just finished up pulling off the intake manifold, only to find out that the gaskets were set correctly in the first place. It's a bit disappointing to know that I have to get new gaskets now and put it back together, but at least it's one less variable that I have to worry about.

I've gone ahead and posted a picture of what I found--obviously, everything looks good in there. Looking at the gaskets, however, did remind me of something. Look at the part of the intake gasket towards the firewall. Notice how that last port is largely blocked, with the exception of one smaller-than-a-holepunch sized hole. Now, on the intake mainfold, I know that that port doesn't actually flow anything (why, I don't know). But that reminded me of something that I thought was odd a few months back when I put the head gaskets on (also blue Felpros): between the cylinders, where the coolant ducts are, I ran into the exact same deal (one of those little holes instead of a hole cut out to the shape of the actual port). I think that *has* to impede coolant flow between the heads and the block--but I figured that FelPro knows what they're doing.

What's FelPro's rationale behind putting such small holes instead of actually cutting out a port there? Or did I put the wrong head gaskets on?

 

I fished up a picture of the head gasket before the engine was completely reassembeled.

The parts circled in red are what I'm talking about: beneath those tiny holes are coolant ports about 10x larger in diameter than the tiny holes in the gasket.

I'm wondering if mabye this might be why I'm overheating.

 

Before you go removing oil pans and timing chains try to get a degree kit and simply degree your car. If the timing chain is OFF your camshaft will be OFF compared to your crank. Thats the easiest way I can think of... visibly if the chain is off 1 link you can almost watch the valve move and check your cam-card... you should be able to tell if its off 18*~

As for coolant flow, did you ever take off your radiator cap and just LOOK and SEE if water was flowing? I think that would be the easiest way to check for proper coolant flow. Especially with a high-output water pump...

And remember AIR can play a role in your water jackets. on a new engine with no water in it, I find I somtimes need to "prime" or squeeze my radiator tubes to force some water into the engine block to get it flowing. I did an engine rebuild and it would quickly overheat right after starting, the oil would begin to boil off the head! I pulled the intake off, checked my timing, etc... A simple squeeze on the radiator hose and it was fixed

Personally, Even if water was not flowing, An engine should still run good for the first few minutes even with no water at all... It shouldnt have problems going into gear and idling.. If it does, its somthing besides just the water... overheating however... can play a role in spark timing, but not necesarily engine idle quality... It sounds like you may have 2 different problems, and your searching for the reason your car is overheating when actually there is ANOTHER problem you may have yet to discover, Like the timing chain or ... .??

Just trying to help! good luck with it, I know how frustrating it can be.

 

Sancho,

Just to attempt to address your question about the head gaskets. I felt the same way when I got the felpros. But after looking at the factory ones from the old engine it had the same tiny holes. I figure both gm and felpro can't be wrong right? Well anyway I am running those and not having the problem you are.

Also my timing chain was pretty tight when I put it on and it was very obvious the marks lined up. I think a timing chain set is relatively inexpensive. Maybe someone will correct me here or enlighten us but I would not think a loose timing chain from the beginning would not be a good thing. If it was pre-stretched why not design it so that after stretched it would be tight.

I mean we are talking about a part that is responsible for ensuring your valves open precisely(spelling) during piston revolutions that could destroy your valves. That is probably what bent ChevyKen's valve that Vador mentioned.

Let us know what you find.

 

They put those holes in different places to regulate the relative amount of water flow to various points in the motor... that part of the engine on the intake side generates very little heat, and so needs little water; the hot part is on the exhaust side, especially at the center where the 2 exhaust ports are together. Note how there are 2 large holes over there.

There's a clue in your original post... "won't really idle with the timing set to 'spec'". Have you tried setting the timing to where the engine wants it to be, i.e. as far advanced as it will go without pinging, and see if that makes a difference? Your entire problem may just be that your balancer is even more fornicated than they usually are, and when your mark says your timing is at "spec", it's really somewhere way retarded.

 

MMMM, very, very familiar.

The last year, my engine was rebuilt for a mechanics, and a pinging & knock was on.

Then, I started with a search and i tought that I need do a timing retard. I did the timing retard changing the spark advance tables into the EPROM.

How much timing I retarded for no pinging or knock??? = 18º !!!!

Now, I'm understanding and I'll review the timing chain.

(Other bad condition was : the rocker arm NUTs are bad, I'll change too).

Regards,

Denis V.

 

Do not always trust your balancer! The outer ring on the balancer can slide and cause the timing mark to be off. That same problem happened to me on an engine that I rebuilt. I used the original balancer and set the timing with my light to 8 degrees and in five minutes of initial startup and brek in procedure my engine was at 200 with a 180 thrmostat. The fix: I bought a chrome degreed balancer cover from proform and installed it. The exhaust gasses were so hot it turned my header wrap jet black in just 5 mins.

 

Kingtal0n: Well, if there's a way that I can confirm my suspicion that the timing chain is off a few degrees *without* removing the timing cover, I want to try it. Where can I get some info on/buy a degree kit, and how much does it cost? I'm not at all anxious to drop my oil pan, break all of my fresh seals, and risk an oil leak on this engine if that's not even the problem...

There's definately flow through the radiator--in fact, it's noticably more turbulent than it was before the rebuild.

jimmy_mac: Regarding the timing chain, I've not been too pleased with it. It's exactly like the one I pulled off (although new, of course) and, like I said, had about the same amount of stretch in it. I wouldn't have been my first-choice, but that's what we got from the machine shop so I stuck with it. I would have liked to get something a little more "fancy" (i.e. something that would be potentially more reliable).

RB83L69: That explanation about the head gaskets makes sense--actually pretty smart on FelPro's part. Although, interestingly enough, I can remember that the original GM gaket allowed for much more flow through those parts (the holes were the same size in the gasket as on the block/head).

Regarding the "won't really idle with the timing set to 'spec'" issue... I should probably clarify. I actually *can* get it to idle at the spec base-timing, albiet not as smoothly as if it were to be advanced beyond the stock base. The stipulation there is that it will only work like that when it is warm/hot. If I leave it at spec and it's running one night, but then I turn it off and try to start it in the morning, I'll have to go and advance the timing quite a bit just to get it to start. And when I have to advance the timing like that, the idle won't go below ~1100 RPM--so I have to wait for it to warm up for a little while, and only then can I set the timing back to where it "should" be (which will also lower the idle a bit closer to earth). That's what's confusing me and making me think it's not just a simple "I can't find the sweet-spot": I can either time it so that it will start cold and idle irregularly high (and overheat), or I can time it to spec and not be able to start cold (and it will begin to overheat after its warm enough to sustain an idle on its own). Being able to both keep a reasonable idle speed and being able to start cold shouldn't be an "either-or" timing situation...

Thanks for the replies; keep 'em comming.

 

Sancho,

The King is right. A degree wheel would reveal any valve timing issues. Since the degree wheel mounts to the crankshaft, you can check the valve timing with the timing cover in place. The degree wheel instructions can be found here:

http://www.cranecams.com/instruction...ing/degree.htm


That's how I founds Ken's problem. However, once I did, the timing cover had to come off anyway to repair it. Actually, the difference of one cam sprocket tooth is 17.75°, but 18° is close enough for argument's sake.

 

I was just thinking about the looseness of your timing chain and it jarred something loose in my tiny memory about engine rebuilding . You mentioned that is a fresh rebuild on the engine. When you had the block machined did they by chance to an align bore or an align hone on the the cam bearing surfaces? If I remember right either the align bore or the align hone moves the center line of your cam closer to the centerline of the crank. Bascially it means that you will have more play in the timing chain and in the worst case need a custom timing chain to compensate for the excessive slack. I will have to do some research find out which method moves the centerline.

 

Ok here is some info that I found on both Align boring and honing.

The practice of align-boring the main bearing saddles and main caps is helpful in that it guarantees minimal drag on the crankshaft. On the other hand, it moves the crank closer to the cam by a small amount, which has the net effect of lengthening the timing chain, directly affecting cam and ignition timing. The process of align-honing removes far less material, and is unlikely to cause timing problems. If you suspect that a potential block has been align-bored, be certain to have a qualified machine shop measure the distance from the crank to the cam to see if (or how much) it differs from stock specs.

 

<b>(i.e. something that would be potentially more reliable).</b>

Then do what I did to ensure that I never have timing chain issues ever again:
Buy A Gear Drive.
lol in all seriousness, I will never go back to a chain. Edelbrock's Accu drive is by FAR the quietest gear drive I have ever heard (in my engine) and its exactly precise in keeping timing, not to mention NO CHAIN STRETCH and NO WORRY ABOUT JUMPING TEETH <../rant..>
anyways, figure this into the equation:
The timing chain controls your valves, not your ignition, So technically if your timing is advanced / retarded 18~ degrees, your engines valves will be opening 18* sooner / later right? Now, would this affect tempurature?

I have a feeling your problem is more ignition related than you realize, considering you cant get it to idle correctly with the timing the engine likes...
Did you put a hotter cam in? radical cams like alot of advance or they will cause very crappy idle quality. Also:
when your timing is retarded past or near 0* BTDC your engine will not START but it WILL RUN at negative 0* BTDC. if you even TRY to give it throttle though, it WILL backfire...
Piston location VS ignition timing must be correct in regards to your balancers mark, or you will never dial in your engine. To rid MYSELF of these problems I dropp $140 on a streetdamper/fluidamper its case is laser welded and has no ring to slip and throw off your timing. In your case, I would recommend:
Find some way to get piston #1 at TDC (i.e. Piston stop / feel for compression stroke etc...)
With piston #1 at TDC Check your distributor's rotor. Its pretty easy to tell where 10-15* BTDC is on the rotors, and if you use a protractor to find (360 / 8) degrees (45*) you can almost perfectly guage out where your distributor should be. This is how I time all my engines, (protractor) because I have no timing light. I then control mechanical advance using an advance kit from MSD, But thats ONLY for msd distributors (another good reason to buy one). If you dont have a piston stop, just remove a plug and feel the air rush out as the piston goes up, then right when it stops your at TDC. Remember there are 2 TDC's #1 Compression and #2 Exhaust. Simply look at your valves to see which is which, the exhaust valve will be open on the exhaust stroke. They will both be closed on the compression stroke, and even if your timing chain is off 1 tooth you will still be able to tell where the compression stroke is. This will tell you if your balancer is out of wack, and it will let you set your timing accuratelly. That would be my first step before ripping apart the front end to get to the chain.

 

Vader: That's exactly what I'm looking for. As soon as I can find one (I hope I can get a loan from somebody), that will be my next "plan of attack". Thanks for the link!

studdmstr: Interesting. I'm going to ask the guy who did my machine work what he did to my engine or, if he doesn't remember, what he usually does. If I understand you correctly, then that could explain the extra play in my timing chain (and will definately become an issue if I decide to change the chain).

Kingtal0n: Thanks for the reply. I was seriously considering a gear drive when I did this rebuild, but the thought of all the noise is what scared me away from it (even the manufacturers attest to the fact that there's noticable noise). I've actually never heard what timing-gear-noise sounds like... who knows--I may like it!

With regards to the wether the overheating is timing or ignition related... As I understand it, if there's an issue with the timing chain, the ignition would automatically be an issue as the distributor (ignition) is run off of the camshaft, which is ultimately controlled by the timing chain.

As to what cam I have (is it radical or not)... that's sort of an interesting topic. Without really getting into it, I basically don't know the exact specs on the cam--all I know was that I asked my machine shop (who also ordered all of the parts for me) for a camshaft what was the same thing that GM put in there originally. A big reason for asking for the same thing was that I was trying to have some foresight and trying to avoid having any issues that I'm not qualified to handle. So, hopefully, I got what I asked for. I will say that I "looked really hard" at both the old camshaft and the new one side-by-side, paying special attention to the shape of the lobes and their positions relative to each other, and I can say that they "looked the same". (That might sound like a joke--in reality, I probably can't tell one from aonther. But I acted like I could...).

 

Wow this thread has an incredible amount of technical content, I am amazed.

That being Said, Ill add my .02

In my limited experiance, I have never seen or Heard of an aftermarket or replacement timing chain wich was Loose. Quite on the contrary, The three that I have installed persoanlly Have been so tight as to Be quite a PITA to get lined up properly.

What type of Chain was this they gave you, An aftermarket double roller, or the crappy composite geared single Chain Stock Type ?

The Fact that you mention Visible slop in the chain throws up a red flag to me, In lieu of all your problems would be the first thing on My Mind.

Now, weather or not This will cause your Overheating problem, I am going to have to defer to Vader on this one. Haveing always gotten it right in my experiance, I don't know

Severly retarded ignition however Can and will cause excessive heat. The Ignition timing ( not to be confused with Valve timing, wich is the concern of the timing Chain issue ) Is IMO the trickiest problem concerning Getting non-stock Setups to Run right.

If you have the original balancer, odds are that it has slipped. Timing VIA light as a result is useless. You can either Purchase a new balancer ( wich you don't seem to be in the position to do ) Or, Do it by "ear"

However, enter the tricky part. And Truth is, even with all My supposed experiance, I still get all frustrated and Annoyed trying to do this.

The process you describe of advancing to start and retarding onc eit has warmed up sounds to me like your Running severly retarded.

This is a TPI motor, I trust ?

I would Adjust the timing to where the car idles most smoothly, and Then try going from there. Keep advancing it untill You can get it to idle in gear. I really think your Running quite retarded.

I hope your playing with the timing, with the esc disconnected ?

Having it Connected will play all sorts of games with you trying to get it set right. Get the car idleing properly both in Park and gear Before you reconnect the esc.

BTW, the Cam being off a Tooth on the Chain Will have no effect on resulting ignition timing. Of course if you were to Change the Cam's Position without resetting the distributor, It would. But If the distributor is set properly nowTo the wrong cam setting, then it will work fine. The ignition timing, that is.


I agree with the above poster who said it sounds like your Chasing two problems here, But I belive they are stemming from the same source.

Find out why your car will not run right, or idle solidly in gear, and you will figure out why it is overheating.

EDIT: I would just like to add, Sancho, I like your attitude. If only more up-and-coming Thirdgenners Could Follw your lead the information contained within the more experianced memebers of this site could be more easily shared and used.

Keep it up, you will Go Far.

 

I just remembered something, when I was helping a friend rebuild his 350, he bought a standard timing chain. As I put it on, the drivers side was tight, but the passenger side was loose. I called around and talked to quite a few people and they all said the standards were all that way. It has slack in the passenger side due to the rotation and torque. Now when I installed my double roller, there wasn't any slack.

On another note, if you put it together and looked at the timing marks as you put it together, you would definately notice if you were off one tooth. It might be hard to remember, but worst case scenerio, just drop the pan, take the water pump, alternator, power steering, and balancer off, then pull the timing cover. I know it sounds like a ton of work, but look at all the experiance your gaining. If anything, the next engine you build you won't have to rely on the machine shop as much. Good luck!

 

I've been doing all of this talk about how much slack my timing chain has, but I figure the best way to get my point across is to actually show you.

I have in my Yahoo! Briefcase two videos that I created back in May of my dad moving the (new) timing chain that is currently in my car. One is a close up, and the other is from farther off. You'll notice that, in the close up, you can actually see the marks on the timing gears.

As you might be able to see, the new timing chain is basically an exact replacement of the GM part (I put the old and new side-by-side, and I couldn't see any differences). If I can remember correctly, the old timing chain (before the rebuild) seemed to have about the same amount of slack as the new one.

What do you think--anything look odd?

____________________________

Bort62: I think I would agree with the "two problems from the same source" idea. Right now, my best guess is that the source is the timing chain.

As far as the balancer goes... several people have obviously mentioned that. I probably need to just go out and *look* at the darned thing, but from what I remember when the balancer was off, I really can't "see" anything that is capable of slipping. If I remember correctly, there's one key in the crank and one place in the balancer for the key to go. If that's the case, I don't really see any room for anything to "slip". I'll check it out, though.

The engine is a TPI engine, BTW.

Thanks for the comment; I appreciate it! I've realized that, when I run into problems like this, I've really got to troubleshoot and try to check all of my options before anything else... Because what I *really* want to do is get pissed and throw a wrench at this engine, but I know that's not going to help anything (and, if nothing else, at least the engine now *looks* better than it did when it had rusted coolant all over it ).

 

dear sancho.
if your overheat is while stationary as on the highway, the problem is only the plastic spoiler located below the radiator, it forces ram-air into the engine compartment across the radiator, so this being damaged will cause the air flow to be greatly disturbed and/or reduced.
as simple as that.
i hope this will help a little, good luck.
by the way, isnt your family name Sanchez? (like mine), 'cause its origins come from sancho (don quijote's friend) from Cervantes, don quijote de la mancha.
Fernando.

 

While what you're saying could be true... I'm not even to that point yet! That is, I've not been able to get the car to move yet--I've not even been able to get it to stay in gear without dying.

No, my name here has nothing to do with my real name... Actually, I got my name here from a Sublime song.

 

I also want to point out that most cam timing is pre-advanced about 4-5* from the cam manufacturer.
This means if your timing chain is off 1 tooth, you have to add in the extra 4-5* thats pre-ground in! if its retarded 18~* then + 4 would be 14* retarded. If its advanced 18~* then +4 = 22*!!

 

<b>After</b> viewing your videos I would personally opinionize that your timing chain is perfect. It appears to be a aftermarkt double roller with typical side play and from the video appears to be lined up perfectly.
Your problem, it seems, is most likelly originating from elsewhere. Start with your ignition timing, Look at the rotor VS piston 1 TDC. See just how close it is... As in my previous post. Find TDC Piston 1, and check where the rotor is pointing in regards to your #1 plug wire. very, very, simple.

 

Kingtal0n: I'm curious about the pre-advancing that you're talking about (and someone else mentioned). Is that same kind of advancing done on the cam that came with the car--or just aftermarket?

I'm assuming that the old "dot-to-dot" method of putting timing chains on wouldn't apply to cams with this pre-advancing. That makes me wonder, though... didn't Vader say that one tooth on a timing chain is ~18 degrees? That being true, how would I ever be able to offset a cam that was pre-advanced ~4 degrees?

Also, what would be the benefit of even doing a pre-advance on the cam anyway?

I'm hoping that this doesn't apply to whatever cam I got...

 

ok heres the low-down on "pre-advanced" camshafts.
Most cams come from the manufacturer with a ground in advance. This means that you IVO IVC EVO EVC (intake valve open, intake valve close, etc..) Occur a few degrees (4-5 usually*) earlier than if it were "stright up", but this leads to confusion because people think just because your "straight up" means you have no cam advance. Not true.
Lets get a few facts straight first.
-advancing your ignition timing has nothing to do with advancing your cam timing.
-Lining the DOTS up on a timing chain set does NOT mean your running "straight up". You can have up to 8-12* of retard / advance on your camshaft and still have the DOTS lined up.
-Valve events that happen SOONER (i.e. an Advanced camshaft) NORMALLY result in a smoother idle, more low end torque, less top end horsepower, and more vacuum at idle. This is the MAIN reason cam manufacturer's PRE-GRIND 4-5* of advance in their camshafts, so if WE (the un-experienced ) buy a camshaft thats just a LITTLE TOO BIG for our application, the added 4-5* of advance will give us back some of that low end we needed to begin with. this is typical with the 450 horsepower @ 6500 RPM engine, But the tranny is a stock 1500 RPM stall and the rear gear is a 2.73. obviouselly, by the time you hit your power band, the race is already over.

So, how do we control cam advance? Well its simple... When you get your timing setup, There is a little "off-set bushing" (uh oh-tell me you installed it!) the Off-set bushing(s) can Retard / advance your camshaft a few degrees, giving you more "low end" or "top end". Its a little round piece of brass (usually) comes in different colors and fits into a little hole under the cam lock plate (usually).
If you DONT Install your cam-offset bushing, And your timing set REQUIRED that you install one (usually) then your timing chain will constantly bounce around your camshaft's timing! At least this is what happened to ME when I Forgot!
Remember cam-walk (forgettng to use a cam-button) can also affect ignition / cam timing. even if you dont have a roller cam, its posibble to have cam walk and then you really cant figure out why your engines idle wont stay still... (happened to me too!)

Do you know if you installed the off-set bushing? do you know if you installed a cam-button? did you check the clearance of the cam-button to your timing cover? Did somone else supposedly do all of this but your not sure?
Cam timing issues dont take alot of experience to understand, but its easy to forget 1 of the many things that can go wrong during a buildup. Somthing as simple as forgetting to put a little piece of brass in you timing set can mess your whole engine up.

 

Hmm... That makes me wonder, then...

If the reason that a cam manufacturer might want to pre-advance a cam shaft is to make it work better in applications that it wasn't really meant for (i.e. like you said: putting in a camshaft that's too big), then what happens if you've got (what I trust to be) a "stock replacement"? That is, you're replacing an original GM camshaft with an aftermarket that's "supposed to be" or "is very close to" the original GM part that it's replacing?

That's what I asked for, anyway--I specifically *didn't* want a radical camshaft because I didn't want to run into any issues with having to "retune" other parts to work with a different camshaft (I'm not that good yet ).

So, what I'm wondering is if mabye my camshaft--if it is what I think it is--possibly *isn't* pre-advanced (does that ever happen?).

Regarding the cam-offset bushing... I can honestly tell you that I can't remember ever seeing any such thing while pulling the engine apart and when putting it back together. On both the cam that I took out and the one that I put in, the end had three equally spaced screw holes, and between two of them there was a little pin/key to make sure that the timing gear goes on the correct way. The timing gear had exactly the same number of holes (four total) in exactly the same places. And, of course, the timing gear on the crank could only be put on such that the key in the crank matched up with the indent in the gear. So, I don't really see any way to "adjust" anything; there's only one way to put that stuff on (short of getting the chain out of timing--which can only happen in 18 degree increments). And, as we can both clearly see from the videos, the timing chain looks as if it's on correctly (dot-to-dot).

Mabye my camshaft doesn't have that, either?

 

Sancho: Then, you could try with the old camshaft "as is", later with the same old camshaft "machined" and compare the "overheating" condition with the new camshaft. Thus, you'll can "isolate" the camshaft effect in the overheating.

Regards,

Denis V.

 

Sorry I've not replied in a while. I've not really had much time to work on the car.

But, I've been having this thought... Is it possible that mabye the problems with the overheating and bad idle are both due to *ignition* timing issues? For example, if I just had the distributor off by one tooth, might that cause the problems I'm having?

The way I see it, dropping in the distributor would cause artifically advanced/retarted ignition, correct? And either one of those things could cause overheating and a high idle/reluctance to start, right?

Short of having a timing kit like Vader recommended to make absolutely sure (and I'm still trying to get my hands on one), I just don't think that I put my timing chain on wrong (based on the videos).

Mabye it's something that simple. Guess I'd better put the top of the engine back on before testing it out, though...