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lamans71 · 03-08-2021, 07:31 PM

Unfortunate news on the setback and the need to pull the engine back out, but good news that nothing major was damaged.

Two questions for you on the EFI system. Did you install new fuel lines or find a way to reuse the stock prebent lines? I'm guessing that the stock lines are not up to the challenge of the EFI pressure but curious how you went about it. Also did you bypass the charcoal canister/standpipe system (assuming you had those in your car), or find a way to incorporate all that in.

HWYSTR455 · 03-08-2021, 08:02 PM

Quote:

Originally Posted by lamans71

Unfortunate news on the setback and the need to pull the engine back out, but good news that nothing major was damaged.

Two questions for you on the EFI system. Did you install new fuel lines or find a way to reuse the stock prebent lines? I'm guessing that the stock lines are not up to the challenge of the EFI pressure but curious how you went about it. Also did you bypass the charcoal canister/standpipe system (assuming you had those in your car), or find a way to incorporate all that in.

You can reuse the original lines to a degree, especially if you are using a deadhead system.

With that said, OE lines were 5/16 or 3/8. 3/8" is kinda like AN -6, but not 100%. It's more like 85-90%, due to slightly smaller inner diameter, and production variances. Personally, I would never run OE lines, especially if they are 50+ years old.

If you are replacing lines, ordering the OE 3/8" size totally makes sense, but again, you will be limited to HP and deadhead system.

Some try to use the 'one-size-smaller-line' for return systems. That works, but about as good as using the OE 3/8" line, just 'kinda' works, and again, you would be limiting power and system design.

Some companies bend 1/2" line to OE shape, but with larger diameter, you can't do as sharp of bends, so they never really fit like the OE ones. And unless you're running deadhead, the return would be on the other side of the car, would still have to fab something to reach the return on tank. So might as well drag 2 1/2" lines on whichever best path you can find, and run a bypass/return system. (It's the best solution, and the OE argument is only because there was a cost factor of like $6 they were trying to save, and run higher psi).

On the standpipe thing, That's what I do, I delete the charcoal can, and use whatever vents the tank has, run to it, and the return 'pipe' I use the largest line back to the tank. Leave the remaining 'tall pipes' venting into the air. All my 'garage gas smell' issues went away doing this.

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Scarebird · 03-08-2021, 10:20 PM

I ran repop OEM style lines in the stock location. I also reused the stock 71 vapor/liquid separator and charcoal canister with new charcoal in the existing return line. I was concerned about the gas smell as my older cars had the issue. This one does not. The carb line I will put a port on the air cleaner for this

lamans71 · 03-09-2021, 12:29 AM

Thank you both HWYSTR455 and Scarebird for explaining how you both went about doing the fuel lines for your systems. Great thoughts and information, and apologies for hijacking your thread for a bit Scarebird.

Scarebird · 03-09-2021, 02:08 AM

not an issue - it is why these threads exist.

My LS3 swap did kind of the same thing - would not be emissions compliant without the charcoal box and separator loop

Scarebird · 03-13-2021, 09:25 PM

Yarded the engine out. One of the few times I wish it was an automatic!

Seat belts arrived. Will see if I can get them to fit correctly.

Ram Air III manifolds and 2-1/2" exhaust are not a good fit - getting those nuts on is a pain in the ass. I am thinking of doing what the factory did but not happy with a 20% flow reduction in that section.

roger1 · 03-14-2021, 08:11 AM

Glad to see you are moving along with fixing the issue. I know how it goes when you have a disappointment along the way in a project. Once you get get going dealing with it, you quickly forget about the frustration.

Btw, I just bought the RARE large opening ram air exhaust manifolds and 2 1/2" down pipes. Can you explain what kind of difficulties that will present? Does it make any difference that my '69 GTO is an automatic?

Scarebird · 03-14-2021, 10:46 AM

Roger, I do not know if the large opening manifold has a larger retainer - the nuts hit the pipe and forget about using a socket. You will need a stubby wrench and a Crow's foot to get these in.

According to Rocky Rotella's new Firebird book, GM inserted and welded a 2-1/4" elbow with flange on the Super Duty's which had 2-1/2" exhaust - I am thinking that speedy installation was the issue.

Image courtesy Rocky Rotella's "The Definitive Firebird & Trans Am Guide 1970-1981

I will contact Ames Monday and see if they will let me ask their exhaust vendor if they can make a pair of these stub elbows. IIRC the guy is in Nebraska and makes them per order. His quality is superb; the set we installed on a 1968 Firebird fit almost perfectly.

roger1 · 03-14-2021, 11:11 AM

Thanks for response.
I ordered and just received my RARE manifolds and Pypes 2 1/2" down pipes w/flanges. With the parts on the bench, I mocked it together and I can get a socket on the nuts just fine. So it seems I should be OK.
As far as those stub elbows you show, I don't think you will notice any degradation in performance. It is such a short length, it will hardly add to the total pipe friction of the entire system.
I studied fluid mechanics in college and I've actually seen situations like this actually make an increase in flow due to the fact the smaller section increasing the flow speed of the fluid and then dumping into a larger section. Anyhow, don't get bummed out at all with having to do this for the convenience you will get.

Scarebird · 03-14-2021, 12:51 PM

ah. Cross sectional area was down 19%, but I believe what you say. I remember HVAC elbows incurring a loss, but mainly from change in direction. SMACNA (HVAC union contractor group) had films during my apprenticeship that showed the flow of smoke in a rectangular elbow - it followed the outside wall so the exhaust may behave the same.

I will decide tomorrow - if the guy in Nebraska can make the elbows I will get them.

If not just run what I have.

fairwayhit · 03-14-2021, 02:16 PM

Hey Scarebird, The bumper on the left looks “thinner” the the one on the right. Did Lemans have two different types of chromed bumpers in 71 or is it just the camera angle?

Sent from my iPhone using Tapatalk

Scarebird · 03-14-2021, 03:53 PM

I think it is camera angle - both were identical.

Scarebird · 03-16-2021, 12:59 AM

Pulled the pan. You can see where the dent pulled the metal down away from the timing cover. Some work with a pick hammer or center punch may have fixed it, but not well.

Put a Milodon pan - nice unit, heavier than stock. Paint was the correct weird greenish-blue.

Broke a stainless exhaust bolt too, yay. Will Helicoil the exhaust manifold holes. Had some 30+ year old Eastwood Stainless coating for exhaust, reanimated it with reducer - will see if it sticks...

Scarebird · 03-17-2021, 10:49 PM

Different stuff today.

Helicoiled the exhaust manifold holes, fabbed a little tool to ensure a straight drilled hole with a machined locator.

Shoulder belts: I was still mulling how to mount these little buggers. Initially I was going to put them on the floor but realized they fit perfectly on the top mechanism pivot perfectly - no drilling. These are inertial reel type; work at any angle. The line chalked in is where the little blank off cover is.

I will need a grommet for the top mechanism shield hole I will need to cut and fab a bracket for the outer floor mount.

These may work - made for Bride racing seats but will need to clear the buckle.

tjs72lemans · 03-18-2021, 07:29 PM

I like that idea. You have to modify your side trim panel to accept this then?

Scarebird · 03-18-2021, 09:35 PM

Yes, only thing I could not get around. Made some test bezels out of billet, if we make more will 3D print them.

Scarebird · 03-25-2021, 01:07 AM

Got more of the unique 71 engine paint; it has that weird greenish cast to it. Remounted the exhaust manifolds and engine mounts.

Something else I was playing with was the ignition wire routing. I was always annoyed at the sloppy way Pontiac routed them OEM. I picked up a couple sets of these Dorman loom clips, they mount on a post. Seemed like a winner till I tried to open them - extremely brittle and they broke. I am not a chemist but note these are way too hard for the task they have. Dorman's quality control is crap also with their dust caps, unfortunately they are the only game in town for those. I ended up using a different style and mounted them to the back of the cylinder heads to clean up the wiring. This of course meant changing the wires around and making new ones too. One thing I will pay extra attention to in the 5-7 routing. GM warned explicitly in my 83 Shop manual that they are not to run parallel to prevent high speed misfire.

Engine was dropped in today which ended the day. Milodon pan cleared with no issues other than the frame engine mount lower bolts had to be flipped to clear.

HWYSTR455 · 03-25-2021, 07:52 AM

There are exhaust manifold nuts with long shoulders, those should work if the pipe flange extends too far. There are a bunch of sizes/lengths available.

For looms, you can just make some out of stamped steel, and then plasti-dip them. I at one point did this, and made bends in a bench vice, they turned out nice.

I like the Milodon pans, and you can retain the OE dip stick/tube config.

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Scarebird · 03-28-2021, 08:38 PM

HWYSTR455: I found that if I used a ratchet strap and wood wedges I could move the pipes for much better access. Also, a crow's foot wrench with extension and T-handle works really nice!

Seat belt time.

Earlier I had mounted the retractor, now for the other components. I had some 3/16 steel laser cut as shown. The first piece I countersunk where needed and rounded the edges. I bent them as shown, in hindsight they stick out 2" too far. As you can see they sit under the headrest buttons. If I decide to produce these, they will be silver zinc plated - I do not think paint will hold up. Another thought is to 3D print them too - the factory uses plastic for the guides.

The floor anchor was fabbed out of some 90 degree steel laying about, holes are offset for access and the belt anchor bolt welded in 2 placed for ease of installation. A pair of washers and a Nyloc nut finish this end of things. Depending on cost the floor anchor may get a nice little boot to cover it, but currently it is very functional.

It works very well. A local outfit will most likely 3D print up some pass thru bezels which should complete the test setup.