F14CRAZY

Supercharging (this time, it's real)

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If I may add my two cents: Although I admired your enthusiasm and all the effort you have put into the project thus far, I must also encourage you to put the parts back on the L-67. Another point for doing so is the fact that the bottom end of that motor was built for the extra power. The conn. rods for example are different, for a reason.

We're all still pulling for you. cool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gifcool.gif

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Thank you Padgett and Maui.

I agree. Pointless to keep doing something over and over when you keep getting the same result. I've done this with the gaskets, but am figuring this out.

I wonder what 2seater's experience with head gaskets has been. But you know, very possible mine was weak to start it, whether boosted or not. It probably blew due to the boost. His engine has pretty much stayed together while making 260-280 hp. What may be the fastest non-prototype Reatta is based on an LN3. What I wish to say is that I don't think my efforts are in vain.

Yet.

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Willren seems to be a knowledgeable guy that has experimented extensively with s/c engines although not exactly what you have done. The oil problem does sound like a head gasket, the leaking coolant in the throttle body wouldn't have any direct path to the oil. It would either leak externally, or possibly get sucked into the air inlet path. The PCV system is somewhat divorced and even if it pulled some of the leaking coolant it should be into the intake tract? I can't imagine you developed enough boost to have bothered the head gaskets up to this point unless a pre-existing condition existed, or it got into detonation but that should have showed up on the knock sensor? Head gasket might show up on a conventional compression test but a leakdown tester would be best. I don't see any giant advantage to the L67 heads unless they have roller pivot rockers but I suspect they do not. They would allow the integrated PCV system to be fully functional, which would be neater and cleaner regarding appearance, but of no real advantage as long as the external system is working. I do not know if the head gaskets are different, and it is possible they are. Only comparing them would tell, or check the part numbers? If so, my fingers are crossed on mine too, although I have 25k miles on my stock vin C rebuild with up to 10+ psi of boost on occasion frown.gif Curious situation.

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Thank you 2seater. Support is good.

Do you think that the head gasket leak would let coolant up into the intake manifold and throttle body? I'm thinking I've got that and the throttle body heater leak.

I suppose my PCV system, with the front valve cover being connected to the throttle body, and the rear valve cover getting vacuum from the tree, could be the source of the leak. I guess the only way to know if my head gasket is bad is to go ahead and do a leakdown test. I'm going to check on the hardware to do this tomorrow.

Your words seem positive 2seater. But note to all...I don't at all mind criticism. I'm one of those that find it "constructive." You guys know tons more than I do when it comes to this stuff.

We'll see. Thank you.

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Well, my PCV intake is in the Fernco in front of the throttle body. I really don't think my vacuum for that is enough to draw coolant upstream, through the throttle body, and into the engine via the front valve cover tongue.gif

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I do not know if the PCV system could possibly pull coolant from a leak in the throttle body. If I remember the photo of the engine in the car the air filter is fitted directly to the MAF, right? The air inlet line from the front valve cover should be into the air tract ahead of the MAF/throttle body, I don't think there is a fitting for that purpose on the body itself since it wasn't designed for an external system. I would guess the line is attached to the flange on the big side of the filter. If that is the case, I don't see how coolant could get to it. I cannot think of any path from the head gasket to the intake that would leak coolant to the intake. The cooling system is under a pressure higher than anything you will see from the blower, so if a path exists, the coolant would have the pressure advantage. The only way I could see the coolant leak at the throttle body getting to the oily side of the engine would be if the inlet to the PCV system is somehow connected to a point close to the leak and vacuum from the PCV valve from the vacuum tree on top would tend to pull it into the engine. The throttle body gasket is a pretty good design with discrete silicone ribs to crush down and seal everything pretty well. A missing bolt could cause a leak, but unless the gasket is physically damaged, it looks to be reusable, and would likely seal up fine if all the bolts are tightened evenly.

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It's not all bad. A leakdown test will give a good idea of the internal condition of the engine, not just the headgasket. Rings, valves and of course into the coolant system will all be revealed.

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Philip, don't let this temporary setback get you down. Chalk it up to a learning experience instead.

If you go ahead with a leakdown test, make sure your radiator cap is on and you have some coolant or water in the overflow tank. If you have a blown head gasket, air bubbles will come up in the overflow.

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93+ series one 3800s had roller pivot rockers with a solid tip, but are not interchangable to the LN3 head unless you drill out the pedestol to a 3/8 hole from the 5/16 hole other wise they are a direct application

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I picked up an Actron compression test kit at Advance. I used it without the gauge. With the radiator full of water, radiator cap on and locked, and the coolant tank mostly full. I removed the spark plugs and threaded the hose into each cylinder, attached the air compressor hose (around 115 psi) and turned the harmonic balancer clockwise by wrench/hand until the valves closed and I felt the engine to be in the power stroke. Could tell when the valves were closed cuz the crankshaft was really hard to turn. I held the wrench so the cylinder would stay in the power stroke for at least 30 seconds each. I could hear a tiny bit of air movement I suppose because of blow by but I think it's negligible.

However, I did not get any water movement or air bubbles from the two ports that go to the S/C and throttle body (were otherwise filled to the top), the coolant tank, or the top of the raditor. I checked the radiator last. When the compressor wasn't on, I listened closely and couldn't hear any air bubbles anywhere in the system. Did this for each cylinder.

I really don't think my head gasket is faulty. What do you suggest next?

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Forgot to say: the hose I got with the kit had a schrader check valve. I did remove this and made sure air was flowing through the hose before threading into the cylinder

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Think we are back to the possibility that despite everything bolting up, there is a difference between the "L" and "C" heads that is causing the problem. Either that or the s/c manifold is damaged.

Now that everything is apart again, how difficult would it be to put the original N/A manifold back on (after flushing the engine) and try that ? Since you have the original computer, just replace the original PROM.

Never know, something may jump out at you, is just an itch I have.

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Thank you Padgett. I'm going to take off the L67 manifold tomorrow and inspect it closely. It may be damaged and leaking into the area right below it in between the two banks. Don't know what this area is technically called. Are the intake manifold to head gaskets reusable? Not being cheap but I wouldn't have to order them.

Page 1 of this thread has a photo of the L67 with the manifold off, and page 2 has a few relevent photos with the gaskets and manifolds side by side. I took a few minutes to review them and rethink things, but I can't figure out why our L67 manifold wouldn't be compatible. I'm thinking that unrelated to compatibility, the head to manifold gasket is leaking. I've got more or less important stuff to take care of tonight but will pull off the manifold tomorrow.

If all else fails, I can try the LN3 parts again and see if it runs. Problem is that I no longer have a stock '89 Reatta memcal. Closest I have is a '90 Lesabre, which ran the car fine, but instrumentation and the ECC were "out there". And that's a lot of work.

There's something wrong, somewhere. It can't be that difficult. We'll find it.

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I was under the impression that the intake from a later model, 1991 and up would not fit the earlier engine blocks. When I had asked about putting on a

later model fuel injection manifold I was told this by someone, I don't remember. Can anyone verify this for me?

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Jon, all I can find in previous posts was an answer to your question about swapping to the '91 injection was that to do the swap you also had to use the '91 heads. That came from Greg Ross.

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Which means that they don't match. So am I wrong in saying that

is what the problem is with the Supercharger setup??

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I'm going to closely check again, but like the photos show on Page 2, there doesn't seem to be an obvious reason why it wouldn't work.

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Maybeso.

Remember that Greg started with an "L" crate engine.

Have also heard that due to different PCV routing, you cannot put "L" heads on a "C" block.

Sounds like to supercharge a Reatta, it is best to start with either an complete L-67 or a turbo(supercharger).

BTW the area between the banks is called the "valley". Some engines (like Pontiac 400s) have an open manifold between the runners and a seperate "valley cover".

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Yes, the PCV is different. I guess it's the extra round port in the head to manifold gaskets. But, so what? It should just dead end there. How would it be an issue?

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From 63viking's thread, this is what 2seater said about manifold and head compatibility:

<span style="font-weight: bold">I have a '92 aluminum TPI manifold and it will fit just fine. All the bolt holes and such are in the same place. The difference is in the PCV port in the opposite corners of the manifold that would be blocked on a Vin C head although it appears a hole could be drilled in the earlier head to make that functional</span>

So, I'm thinking my gasket just failed

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Theoretically the intake gaskets with the silicone o-ring style sealing is reusable, but if there is a possible coolant leak, or you see any evidence of such into the valley, it isn't worth the money to try to reuse them. I do not know if you have run into this problem or not, but I have had a couple of problems with the valley end seals splitting, meaning the clearance is smaller than it should be. The recommended fix from other 3800 users was to apply a solid small bead of silicone instead of the end seals. I was told to let it firm up a bit but still pliable before installing the intake. It would be a long shot, but maybe insufficient clearance exists on the ends to allow the gasket at the heads to pull down properly? If that was the case the end seal should be split in two. The deck height of the two engines is supposed to be the same, so the spacing between the heads should be also, but subtle differences could exist and be tough to spot. The intake gaskets are big and thick and should allow for a fair amount of manufacturing tolerance. The coolant ports in the intake aren't eroded are they? This is a fairly common occurance, and usually some does exist. The gasket does a good job of sealing but only if the erosion hasn't progressed outside the seal area. This could leak coolant into the valley and thence the oil.

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Will be opening it up tomorrow. If the coolant leak has taken place here, it should be obvious once I get it off

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Due to some goofy scheduling today, I think I'm going to "dip out" of my afternoon classes and commence the investigation of the manifold

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