C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

1990 Engine Swap

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Old Apr 26, 2015 | 04:25 AM
  #201  
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I got it in the car tonight. The input shaft on the transmission went into the clutch disk, and I believe the tip of the shaft went partially into the pilot bushing, but there's still about a 1/4" gap. I think it's an alignment issue with the clutch disk (even though I used the alignment tool when installing it) so I plan to hook up the slave cylinder, bleed it, bolt it on to the housing, and push the clutch in to see if that helps.
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Old Apr 26, 2015 | 01:11 PM
  #202  
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When I assembled my flywheel / clutch; I left out the trans until the very end.

with the input shaft/ clutch alignment tool installed, assemble the whole darn thing, pilot bearing,flywheel, clutch disc, pressure plate, bellhousing, throwout bearing , throwout bearing fork, clutch save cylinder, hose, etc, etc, everything EXCEPT the trans. It also makes reaching the upper bellhousing to motor bolts much easier.

now you can bleed the system and visually verify that everything works, the main thing being that the throwout bearing moves a sufficient amount to release the clutch disc. If you run into problems now is the time to deal it. If you install the trans BEFORE all this is sorted out, you'll probably end up repulling the trans which adds a heck of a lot of work to an already labor intensive job.

when you do install the trans, find 4 really long bolts that are the same od and thread as the four bolts that hold the trans to the bellhousing; cut off the heads and install these into the bellhousing as "guide pins"; slide the trans onto them and the trans will slide right in without all that wiggle motion that normally accompanies trying to "stab" the transmission with possible damage to the clutch disc or pilot bearing.
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Old Apr 26, 2015 | 08:55 PM
  #203  
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In retrospect it may have been better to pull the trans with the engine. I might try that if I ever do it again.

I suspected the issue was misalignment of the clutch disk and pilot bearing, so I bled and hooked up the actuator cylinder then pressed in the clutch (first I aligned the engine and transmission so the engine moved forward and backward freely on the input shaft). My dad pushed back on the engine as I did so, and as soon as the clutch disengaged the engine slid right back onto the trans.

I'm working on getting the motor mounts, ground wires, and bellhousing-transmission bolts all installed.

My new engine has taller valve covers, so my dad noticed the section of the EGR pipe that goes over the valve covers now won't fit (it's not long enough). If I have to, I'll cut it and weld in an extension, but I'd rather not. Any easy fixes other than just buying shorter valve covers?
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Old Apr 26, 2015 | 09:19 PM
  #204  
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Originally Posted by C4ProjectCar
My new engine has taller valve covers, so my dad noticed the section of the EGR pipe that goes over the valve covers now won't fit (it's not long enough). If I have to, I'll cut it and weld in an extension, but I'd rather not. Any easy fixes other than just buying shorter valve covers?
;

you live in California, you're installing a non stock engine in a vehicle that must be smogged, and passing the tail pipe sniffer isn't the usual problem, the problem is the visual; while the tail pipe sniffer is completely objective, it either passes, or it doesn't, the visual is HIGHLY subjective. In other words you want that engine to look 100% stock, no gobbered up egr pipes, no aftermarket, especially taller, valve covers UNLESS you have a CARB decal exempting that particular part. Don't mean to rain on your parade but those are the facts. Yeah I know it isn't fair, but I've been there, done that, and have a stack of failed smog test to prove it.

p.s. aftermarket taller valve covers may not clear the accessory drives, so check all that out before you become too attached to them.
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Old Apr 26, 2015 | 10:38 PM
  #205  
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Yes california is getting tougher with smog. Just a couple of years ago they passed new smog laws that were so tough they scared many smog tech out of the business. Problem was they random pulled over cars tested less than six months previously and the cars had a high rate of failure. Lead the smog enforcers (whoever) to believe a lot of older cars were adjusted just enough to pass the smog test (or worse maybe a stand-in car was used to check the exh pipe). I think they changed the $400 limit on repairs also.

So last time i tested there they even tested the gas cap for leakage. Of course all the numbers (headers and cat). Though i dont think they check the cat location as i didnt see them measure anything with a tape measure. Im sure most smog techs dont recognize every part on the engine so u may have some grace with the plumbing and vlv covers as long as it dosent look to trick. My advice is to go the the cheapest smog test only shop u can find on a busy day. Also remember the smog tech is more worried about fines and penalties than passing your car so u can expect a rigorous exam regardless.
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Old Apr 26, 2015 | 10:38 PM
  #206  
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Yeah... CA smog

Do valve covers really affect smog? I was thinking it was just parts that can affect emissions, like cam, heads, cats, AIR pump, EGR, etc.

$400 limit on repairs? Not sure I've heard of that. I do know they test the gas cap; think it's called the evap test or something. Didn't see them check cat location when I had it tested, but then again the guy was a total idiot (he started it, drove it onto the dyno, then couldn't restart it; I told him you had to push in the clutch and he said, "It's a manual?").

What's the difference between the tall valve covers and stock, height-wise? Looked through the breather hole and I have about 1.5" clearance from the top of the rocker studs to the valve cover. These are nice aluminum valve covers, but if I need the short ones (and they will clear my rockers) then I guess I'll have to shell out the cash to change. Honestly not sure I would have gone with tall ones, but these came on the engine (bought it from a guy in MD).

Last edited by C4ProjectCar; Apr 26, 2015 at 10:41 PM.
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Old Apr 27, 2015 | 08:22 AM
  #207  
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Depressing the clutch for the final mating is normal.

Your new heads have perimeter bolt valve covers?

Adaptors are available from Summit they convert perimeter bolt valve cover heads to center bolt = use the Vette covers from the old engine. Check rocker arm to cover clearance the oil drip tabs may need to be removed.
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Old Apr 27, 2015 | 02:22 PM
  #208  
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Yeah, the new kind have the perimeter bolts. Just looking by eye though, I'm not sure the old valve covers will clear my rockers. If they will it will be tight.

I've got 1.6 roller rockers and AFR heads, if that tells you anything about clearance.
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Old Apr 29, 2015 | 12:45 AM
  #209  
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Got the motor mount bolts all torqued down and got the exhaust manifolds mostly on.

Now that the manifolds are in place, I can see the EGR tube will be an issue. I did a little research, and it looks like the spacers that allow the use of centerbolt valve covers are pretty expensive and also have a bad habit of leaking.

I'm thinking I'll end up welding a spacer or two into the EGR tube.
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Old Apr 29, 2015 | 08:32 AM
  #210  
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Cover adaptors may work to pass visual inspection.

For the modified EGR tube I wrapped mine with a product similar to this:
http://www.motosport.com/product?psr...V58aAjIx8P8HAQ
Then covered it with HVAC silver tape = looks similar to factory install.
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Old Apr 29, 2015 | 10:32 AM
  #211  
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Does the tube need to be elevated to cross over the valve covers? If so, by how much? If you talking 1/4-3/8" on each side, I might be able to build you a spacer to fit under each end of the tube were it bolts in place. You would need to give me a tracing showing the outside of the fitting and where the bolt holes are located and the inside diameter of the tube.

If it needs to be taller than this, you might have to cut the tube on both sides and weld or braze in a piece of tubing as an extension.

-John
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Old Apr 29, 2015 | 03:22 PM
  #212  
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I wrapped mine in header wrap, with hose clamps on each end to hold it on.




John, there's about 1/4" gap on one side but on the other it's more like 1".



By the way, here's a picture of my old transmission fluid (with a fairly bright flashlight shining into the side of it). I'm not sure what the GM stuff looks like new, but I'm pretty sure this has been in there for a while.

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Old Jun 7, 2015 | 06:42 PM
  #213  
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Okay, finally finished school so I have time to work on it.

Among other things, I'm working on priming it with oil (using the proper tool with a collar to ensure oil flow to the heads).

I've been using a regular 18v drill, and have gone until the drill got too hot to continue several times, rotating the engine occasionally while doing so. At best, I was able to get oil to come out of all 8 pushrods on the driver's side and 2-3 on the passenger's. As far as I can tell, it is normal for it to need several minutes of continuous priming using a heavy duty drill to prime it, so I'm not too concerned about that.

By the way, how fast should I have the drill going to prime it? The drill's max is only 1600 RPM, about 1/2 oil pump speed at redline, so I've been going fairly quickly.

Anyway, as my dad and I were trying to get it primed today using a stronger drill from a neighbor, I stuck my head under the car, and heard a strange pulsating mechanical noise coming from inside the pan: something along the lines of buzzing or scraping. It is not apparent at lower drill speeds, and does not pulsate directly in correlation (1:1) with drill rotations. (Edit: When I prime it, the drill has a little bit of wobble to it, I think just because of the intermediary shaft not being perfectly in-line with the oil pump drive. The noise coincides with this wobble.) Since the only thing in motion when I hear the noise is the oil pump, I'm nearly positive it has to be coming from the pump itself.

I'm hoping this noise is just air bubbles being pumped through the oil pump, or perhaps vibration from the drill. However, I'm concerned that something could be wrong. I read in a single post on a forum that downward pressure - even the weight of the drill - on the priming tool could cause wear, but was unable to find mention of this elsewhere. As far as I could tell, the guys demonstrating priming in the several videos I watched did not seem to hold the drill up, and none mentioned a necessity to do so.

The oil pump is a fairly new M55HV, with only a few thousand miles on it, and it did not appear to have any problems before I installed it in this engine. If I turn it with a screwdriver down the distributor hole, it turns smoothly, with no binding or interference.


On a much-needed positive note, the "low-profile" Edelbrock Elite II valve covers I got clear the rockers and the EGR tube.

Last edited by C4ProjectCar; Jun 7, 2015 at 06:52 PM.
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Old Jun 8, 2015 | 05:36 PM
  #214  
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If the oil pump turns smoothly with a screwdriver the current noise when priming is no doubt caused by drill oscillations.

Get oil to all of the rockers. Best method for non oilers: Work 1 non oiler @ a time, rotate the engine until the valve is closed, prime until you have oil @ that rocker then move on to the next one.

Since you are having problems on the right bank the oil pump priming tool bushing is suspect. If you cannot get the right bank to supply oil to all 8 rockers post a pic of that bushing it may not be machined properly.

FYI: For a priming bushing I use an old gen 1 distributor with gear & shaft removed + the top bowl is cut off. Early point type or 75 & later electronic (HEI) makes zero difference. If it fits a gen 1 block good to go.
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Old Jun 8, 2015 | 05:42 PM
  #215  
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Glad to hear that, thanks. I was worried I'd have to drop the pan to fix something.

Is the purpose of rotating the engine to align the hole in the pushrod with the hole in the rocker arm, or is it for a reason having to do with the lifter's position in the bore? (just curious)

I compared the bushing on the primer to the bushing on my distributor, and they looked identical. I think the issue is just that I didn't prime it for long enough. We'll see.

Thanks for the help!
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Old Jun 10, 2015 | 10:21 PM
  #216  
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Your almost there C4. Pretty soon that engine will be making noises. Then u get to spend your entire summer getting it "tweeked in". Take it slow and correct the problems as they show themselves.

No more mods now. Drive it.
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Old Jun 11, 2015 | 01:58 AM
  #217  
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Originally Posted by cardo0
Your almost there C4. Pretty soon that engine will be making noises. Then u get to spend your entire summer getting it "tweeked in". Take it slow and correct the problems as they show themselves.

No more mods now. Drive it.


I completely primed it tonight. I decided to take a different approach, and use the drill on a medium speed for longer with a fan on it to avoid overheating. First oil started coming out of the #3 cylinder's exhaust valve pushrod, followed by all the rest on the driver's side, and then one by one those on the passenger's side. It took about 15min total. At the end, oil was slowly (almost imperceptibly) bubbling out of all the rockers except the #3 exhaust, which had oil fairly freely flowing out of it and pooling on the rocker arm. I'm hoping nothing about that seems abnormal to anyone.

Next I'll be installing the distributor and my new valve covers.
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To 1990 Engine Swap

Old Jun 12, 2015 | 12:57 AM
  #218  
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As I had planned, I installed the distributor and valve covers today.

For the distributor, I took the cap and rotor off first, installed the distributor with no gasket, and felt for up and down play in the shaft to ensure that the shaft wasn't bottomed out.

Next, I took the distributor out, set the engine to TDC on the compression stroke of cylinder #1 (intake valve closed on that stroke, and I could feel lots of air rushing out of the spark plug hole), and installed the distributor. Because of the angled design of the gear, getting it so that the rotor lined up with the #1 spark plug tower and the shaft lined up with the oil pump intermediary shaft was trickier than I expected.

Once I got that on, I RTV'd the valve cover gaskets to the valve covers, then installed them after the RTV had mostly cured. They came with metal baffles to install over the breather holes, but the holes in the posts they screwed into were not tapped, so I left them off. After doing a bit of research, I've decided I'll pull the valve covers back off and install the baffles somehow. I'm thinking that since the covers are aluminum the screws are supposed to just tap themselves.

The last thing I did was to install the thermostat. Due to the design of the Edelbrock High-Flo intake base, I had to clearance the thermostat housing a tiny bit on the bench grinder to get it to fit.

One quick question: one of the grommets that came with these valve covers doesn't have a hole in it on the inside. My breather fits in it, but it's pointless since the grommet blocks the passage from the breather to the inside of the valve cover. Is the user supposed to cut their own holes, or is this just meant to block off a valve cover hole?
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Old Jun 12, 2015 | 10:20 AM
  #219  
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If using a functional "breather cap" you may not pass emissions testing.

Stock system uses a non vented oil fill cap, an air supply tube from the throttle body to the right valve cover, a PCV valve in the left valve cover plumbed to the intake manifold.

If the right valve cover does not have 2 holes one for oil fill & one for the PCV system get a breather cap for an early Chrysler V8. It is a sealed unit with a hose connection for the PCV system.

If your PCV is plumbed leave the grommets as is & use the breathers as cosmetic units.
Refill oil with a funnel through the PCV hole.
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Old Jun 12, 2015 | 04:45 PM
  #220  
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My new engine came with breathers that had PCV valves built into them, and the right cover doesn't have two holes. Couldn't I just pull one of the breathers out of the grommet to refill the oil?

I have the stock PVC system. I'm not sure if that is "plumbed" or not.

Out of curiosity, what is the functional difference between the line going to the TB and the line going to the intake manifold?
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