Perkolator

Looking for some assistance with getting my engine issues resolved.

I inherited my dad's '68 Delmont 88 convertible this year and just had it transported to me last week so I can finish the project. He had a neighbor "car restorer" guy working on the car for him for ~2yrs, up until my dad passed away. The mechanic has been relieved of this project due to many issues which I won't get into and the car is now in my possession. Since I have gotten little information out of the mechanic regarding what work was performed, and because I don't know much about cars; I am going at this project pretty much blind and am in need of help. Until I can get the car driveable, I can only work on it during the weekends since it's not at my house. Willing to spend the whole week researching my issues so I can learn and be able to DIY these repairs.


Longblock was built up from the original 350 by a company called "Machine Tech" in Oceanside, CA (reputable racing engine machine shop from what I understand). I called them today to see if they could help me get my hands on the build sheet for this engine (since I didn't get one from the "restorer") and he said he may be able to find me some info in the next week or so once he goes through paperwork. I have no specifics, but do know that the engine was upgraded with: 455 heads, new pistons (flat?), a cam, edelbrock intake, and a new carb. I don't know anything about distributors, so don't know if I have points or an HEI - assume it's HEI since it's not stock engine? Currently has stock exhaust setup, but I have a driver's side manifold that will supposedly let me do true duels if I get a smaller starter installed. Transmission I think is a TH400.

Earlier this year, the car had an Edelbrock/Carter AFB carb on it and it ran like crap. Wouldn't idle correctly, wouldn't run when put into drive, etc. After giving up on adjustments, the "restorer" sent the car to Machine Tech to see if they could tune the carb and diagnose since he is having family issues and no time to work on it. After several different carbs it was determined that the Carter was either a defective unit or not enough adjustments to compensate the idle vacuum problem. The solution was for me to buy a new carb - I bought a Quick Fuel HS-580-VS 4bbl carburetor. Over the phone, I spoke with Machine Tech and they said they were able to get it running enough to set the timing and "set the top end" (no idea what that means...yet!) He mentioned to me that the car will need a few more things to get it finished properly, but they weren't the type of shop for these repairs and couldn't do any more for me. It ran good enough to drive the car 10 miles, so I guess it's WAY better than it was previously.

Off the top of my head, the items he mentioned was that the electronic choke needs to be hooked up. Something about the accelerator pump needing to be matched to the engine/carb. And lastly something about setting the "curve". When all that is taken care of the car should run good. Since I still know very little at this point, I want to learn and be able to fix my own junk since I don't have $ to pay people to do things I should probably learn to do myself if I'm going to own a classic car.

Electric choke questions:
I did research and found a thread regarding setting up an electronic choke. I did see in some pics I took last week that my choke isn't hooked up to anything - likely explains the hard starting issue. This carb's choke has a ground going to the carb, and another tab which is where I assume it needs power from. I think I will go with the oil pressure switch wiring, but need clarification. From everyone's pics of this upgrade, I see a brass "Tee/splitter" coming off the block, where they connect the PS64 pressure switch, but no mention of buying this part with the switch -- is this splitter something I'm going to have to buy also, or should it be there already? Also, does it matter what style of wire connectors I use, or is a plain female spade connector ok? I guess I need to go back and look at what is actually in that spot on my block.

Accelerator pump:
Still researching this one. Understand that if I hammer the throttle, this will shoot extra fuel to compensate for the lean condition when carb opens up? This sounds like the issue I have with the car - motor stalls out when you step on the gas in-gear or when try to go up an incline. Still not even sure of location of this part. Where can I get more info on the accelerator pump and options for replacing it?

Lastly, setting the curve - assume this is a carb tuning after I've resolved my choke and accel pump issues?

Don't have time to work on the car until next week as this weekend is booked, but all help in the meantime is appreciated.
For those interested, all my pics are in my intro thread

oldcutlass

fxFQwRG.jpg

Perkolator

Thank you.

Figured the tee was not a stock setup, I'll get one when I get the pressure switch - what does the other outlet go to? An oil pressure gauge or sensor? I will research again to get specs on the tee needed, I didn't see it before.

The carb is a quick fuel HR-580-VS. It was an alternative to a more expensive Holley 4bbl carb I was told. The accelerator pump is a part on the carb, right? Will I need to exchange the part or is it adjustable?

Thanks for the info on the HEI - I guessed it would be. Dunno what the timing is set to, but the guy at machine tech said it was correct, whatever that means. I think I still have a harbor freight timing light somewhere in my tool collection. I can find out when I work on it.

olds 307 and 403

That Quickfuel should be a good carb but on the small side. You need to find out the curve by revving it up. You want about 34-38 at 3000 rpm but that requires a dial back timing light. The facyory spec for HEI is usually around 20 degrees base but an aftermarket distributor will be different.

joe_padavano

The use of big block heads on a 350 Olds is not necessarily an "upgrade". There are two problems. First, you need to be sure the CR was properly set, either through significant milling of the heads or different pistons. The BBO heads have 80 cc chambers vs 64-ish ccs for most 350 heads. Second, the larger ports on the BBO heads require specific manifolds that have enough meat to seal properly, and manifold port matching. Without this, the flow disruption will negate most of the benefit of larger ports. Of course, you're still stuck with smaller runners in the intake, which make up the majority of the flow path.

I'm not sure this builder was particularly cognizant about Olds engines.

Perkolator

As for the carb, I was told they were ideally looking for a 600, but the QF only came in a 580. I was also told it's a good carb with lots of adjustments and the capability to be upgraded later to a larger CFM - by changing out the jets?

Yes, when the BBO heads were added to the 350, they also had to add in new racing pistons to boost the compression ratio back up. I believe he said they were flat-top pistsons and they were required to bring compression to around 9-10:1 instead of the 7:1 like it would have been without them installed. I do recall them saying that the manifold is a beefy one so that there was enough mating surface - this is the intake manifold, correct? Haven't looked at part numbers, but know it's an Edelbrock. Gaskets for it I guess were "special" and came from Mondello in Paso Robles (olds specialists?)


Since the "restorer" didn't provide me with any paperwork, I called Machine Tech and asked for a copy of the build sheet since they put together the long block and also installed the Quick Fuel carb when it was brought back to them - they're going to get back to me since they're a busy shop and the info is buried in their notes somewhere. Here's the shop website: http://www.machinetechracing.com/ Though I don't personally know these guys, my dad's best friend knows them (and knows cars) and they say they are one of the best shops in that area. I trust the shop 500% more than I do the "restorer".


BTW, I ordered the oil pressure switch so I can wire up the electric choke next week. Skipped the brass Tee since I think I only have a regular oil light, no gauge. Can always get one locally if need be.

Perkolator

Found a guy on Craigslist who is a mobile mechanic and specializes in classic cars, going to have him come by on Friday and help me get a baseline on all of what's going on. I figure $80 for a diagnosis from someone who knows what he is doing and has all the tools, gauges, etc, is not a bad idea since I know very little about engines at this point. Checked his Facebook page and he works mainly on older classic cars and supposedly comes from a racing background. Spoke with him over the phone and he's already got some ideas on what to check out. I'll update after he takes a look.

joe_padavano

Just be aware that many self-proclaimed "classic car specialists" are really Chevy specialists. Make sure this person understands that there are differences (like the Olds distributor turns in the opposite direction from a Chevy).

Perkolator

Guy came out. Opened hood, took off air cleaner and immediately said "this carb needs a spacer underneath..." More specifically an adapter to go from spread bore intake (Edelbrock performer 7111) to a square bore for the carb (quick fuel), and the carb is sucking air underneath. Also said that the intake manifold has a slight leak too and that needs to be fixed as well. Sprayed starter fluid all over with it at idle and it definitely idled up in those two areas. Seemed like a definite obvious issue to me, now that I know about this.

Said intake gasket is an Edelbrock and they're crap, also someone added in a tad of sealant. suggested buy a Felpro gasket for the BBO heads and some black RTV for around the water ports. Also change the oil after doing these gaskets because of possibility of coolant getting inside. Makes sense.

The carb spacer/adapter should have gaskets in the kit and that task is straightforward. Hook up carb choke wire from a different source than what I read here on CO - the alternator wire has constant 12v which is no good and it needs a power source that goes on/off with key. He found a yellow wire on the firewall and it is where he normally gets power for choke on carbs. This wire goes on/off with ignition. Seems like a cleaner location too, I may go with this wife for my power source.

Once these two major air leaks are resolved, then hook up the choke wire, it should run significantly better and only need slight adjustments.

Now I'm really pissed at the guys down in SoCal - dunno how something as simple as an air leak under carb got past 2 different guys with 60+ years combined experience. Morons. I kinda like the mobile mechanic concept - get to see everything he does in person and help out, unlike shops that don't want you in the shop. Also, yes he is licensed and insured, etc.

Will update as I get more done.

oldcutlass

That manifold is for a square bore or spread bore carb with no adaptor required. I'd run a good quality gasket under the carb.

Perkolator

Yes, the intake is spread bore and the carb is square bore. It's definitely sucking air underneath. Idled way up with fluid sprayed under. I even looked on quick fuel website and they have an adaptor going from spread to square. Why would they make it if you're not supposed to use it? If I can get away without it, great - because I'm worried about going taller and having hood clearance issues with the air cleaner.

joe_padavano

This comes up a lot. The E-brock intake is actually dual-compatible. The problem is that the contouring of the carb opening to fit both square and spreadbore carbs can cause a vacuum leak on some carbs if you only use the cheezy paper carb gasket. Get E-brock part number 2372, which is a 0.100" metal spacer that covers the edges of the carb opening. Under $9 at Summit.

Perkolator

Thanks Joe. I spoke with Edelbrock earlier today and they suggested the same thing for the carburetor adapter plate. I think this will be straightforward.

Where I'm stuck is regarding which intake gasket set will be the best choice? currently I read "edelbrock" written on the gasket - they say they only make one for the 455, so I assume this is the 7284 gasket. Was suggested a similar Mr. Gasket 405 as well. When I call auto parts stores, they have the Felpro MS96009 and MS96004 "valley pan gasket" sets. Not sure which is best for my application since I have the 455 heads on the 350.

When the guy was trying to resolve the engine issues, I recall him taking off the intake manifold and he said he got it slightly machined to see if it would seat better -- assume this is the surface against the heads? Before this, I recall him saying something about a "real good" Mondello gasket set somewhere in the engine. Not sure if it's the intake, but the current one surely reads Edelbrock. Just wondering if the 7284 gasket "could" be the correct fitting one, just that he maybe reused it? Who knows, this guy does not have my confidence. I can tell that there was some sealant used on the gasket and that the leak is generally around cyl #5.

joe_padavano

This is one of the few cases where you can't use the stock "turkey tray" intake gasket. The SBO gasket ports are too small for your BBO heads and the BBO gasket is too wide for your SBO. You will need to use an aftermarket composition intake gasket set for a BBO. Auto parts stores will likely only have the stock style metal gasket. The 7284 will be fine (though the heat crossover ports are blocked, if you care). Most aftermarket BBO intake gaskets (such as the Mr. Gasket) are equally acceptable for this application.

Perkolator

So you're suggesting I use the Edelbrock 7284 or the Mr Gasket 405? I saw some reference to these not having the middle port hole and that over time it may blow through on its own, or help it along by starting a hole. When not using a turkey tray/valley pan gasket, the oil can now splash onto the bottom of the intake - not a problem as long as the front and back of the block are sealed up right (use RTV not the gasket strips provided)?

joe_padavano

Or any equivalent brand name aftermarket gasket.

Sometimes these gaskets come with a steel shim that you put between the head and gasket to prevent the burn-through. If you don't use the shim, it WILL burn through and open the crossover back up. Frankly, I'm not convinced that blocking the crossover is a good thing on a street car anyway, so yeah, go ahead and start the hole.

The splash prevention is intended to avoid having hot oil coke on the bottom of the intake, not to prevent leakage at the end seals. If you have an old used turkey tray, simply cut the center out and snap it into the valley to prevent splash. Yes, I've never been able to get the end seals to stay put, so I chuck 'em and use RTV.

Perkolator

here is the location where i've got the leak, idled up when sprayed generally around cyl #5 port
hQ1cD9V.jpg

oldcutlass

Looks like someone put sealer in there for some reason.

Perkolator

Yes it does, but isn't there supposed to be some RTV used with the gasket? I would assume some of it squeezes out when compressed together.

Perkolator

OK, so I think I've narrowed it down and may attempt this one myself. Called and spoke to a tech, Lynn, at Mondello this morning about my engine setup. He said it's a very common setup to have 455 heads on a 350 block - was common back in the day for performance and is even more common now with available aftermarket parts, etc. Weird that not much comes up when I research it online, other than negative comments.

Anyways, he recommended Mondello IG-505-GR intake gasket to seal up the Edelbrock 7111 intake to the G-heads:


I also think I'm going to order up the Mondello HR-351 heat riser block off plates, since I have electronic choke and no need for extra heat:


Also I like the concept of the turkey tray keeping oil in place, so I'm going to order up the VT-581 valley tray and drill/tap the two 1/4" coarse thread holes to install it:



I've been watching some YouTube videos on intake gaskets and I think it might be something I can handle myself and save the $400 it would cost to have someone else do it. Since I have no manual and because it's my first time, please let me know if I have my steps correct:
- disconnect battery
- drain coolant and remove hoses on front of intake.
- detach air cleaner, fuel line/rail from carburetor, all cables from carburetor, then carb itself can come off.
- remove cap from distributor and mark the position of rotor so it gets installed in same spot.
- all items attached to intake manifold should be gone now, so loosen up all ten bolts anchoring it on.
- carefully remove intake in a vertical plane to not spill any more coolant inside valley.
- block off all ports with ***** of newspaper and cover valley with a rag
- remove all old gasket material by scraping clean, then vacuum everything and remove paper baffles
- drill/tap the two holes for the new valley pan addition, then vacuum again.
- remove oil drain plug, then cautiously pour fresh oil over the valley to wash any contaminants out through oil pan
- install valley pan baffle
- de-grease/clean all mating surfaces with acetone on a clean rag
- using fresh RTV, adhere the heat riser block off plates, then encircle the water ports with a thin (1/8") bead of RTV, add a small bead in the 4 corners where the block and heads meet
- add new gasket and again encircle the water ports with RTV, then add a thick (1/4") bead of RTV on the front and rear sills of the block as this will be the only gasket here.
- wait 5 min to allow RTV to skin over slightly, then cautiously place intake on top.
- add a little RTV to each bolt's threads, about 1/3 way up the threads, then bolt down the intake using the torque sequence I found in the Edelbrock 7111 instruction manual.
- reinstall everything in reverse order, only adding in the adapter plate for the carburetor.
- fill up with oil and coolant.
- start her up and check again for leaks with some carb cleaner spray.

how does that sound?

joe_padavano

Search Lynn Welfringer and you'll also turn up a lot of negative comments.

Look, you have what you have, but I'll once again point out that if this head swap really made sense on the 350 motors, it would have been an inexpensive bolt-on for Olds to use on the W-31s.

ThePackRat

I'm gonna let someone else deal with the tech part of this but ......

You'll have to be more specific on those negative comments .....

Are you talking about the BB heads on a SB or Lynn ?.

Perkolator

Ok so besides opinions on people or the setup, I'm dealing with the lemons handed to me and want to get it running - can anyone comment on THAT?

oldcutlass

Joe, I've never attempted or have ever seen BBO heads on an SBO. So my question as the OP"s, how would you approach the replacing of the gaskets to get it back together. I know some have done this swap with the success of having a running engine afterwards. I just don't know what gaskets he would use. I know Im not particularly fond of the gaskets that were recommended as the silicone tends to migrate and leak.
Edelbrock recommends this the stock gasket:
• GASKETS AND SEALANT
1. Use only Fel-Pro Valley Pan gasket #MS96027 or OEM equivalent when installing Edelbrock manifolds for street applications. Mondello
Performance Products (1103 Paso Robles St., Paso Robles, CA 93446, phone (805) 237-8808) offers heavy-duty intake gaskets which are recommended
for high-performance applications. Use IG-490 with 350/403 cylinder heads, and IG-500 with 455 cylinder heads. M.P.P. also offers a
bolt-in Valley Tray to reduce manifold temperature, part number VT-580.
2. Apply Edelbrock Gasgacinch sealant, #9300, to both sides of the manifold as well as head surfaces. This procedure ensures a good seal.
3. Eliminate the end seal gaskets. Use RTV Silicone sealant instead. Apply a bead of sealant approximately 1/4" high across the block end seal surface,
overlapping the intake gasket at the four corners. This method eliminates end seal slippage and deterioration.

Fun71

FYI, some years ago I talked to Lynn about the VT-581 valley tray and he ASSURED me that it would fit under my Edelbrock aluminum intake manifold. I bought it and when I tried to install it, IT DID NOT FIT - the exhaust crossover hit the tray so that the intake didn't sit down onto the block and heads. When I called back and told him this, he said there were two different block configurations and I must have "the other one". Yeah, right. Then on top of all that, when I returned it they gave me store credit instead of refunding my money.

So my recommendation is if you feel the need for a valley tray (I haven't had one in decade or so), use an old turkey tray. Cut the port sealing section off and fit the tray into the lifter valley.

Perkolator

the website specifies the valley tray only fits the Edelbrock Performer 7111, which I have - is yours the Performer RPM intake? That sounds like the reason why?

oldcutlass

However as I posted in bold above it changes with 455 heads. They recommend gaskets IG-500
Edelbrock recommends this the stock gasket:
• GASKETS AND SEALANT
1. Use only Fel-Pro Valley Pan gasket #MS96027 or OEM equivalent when installing Edelbrock manifolds for street applications. Mondello
Performance Products (1103 Paso Robles St., Paso Robles, CA 93446, phone (805) 237-8808) offers heavy-duty intake gaskets which are recommended
for high-performance applications. Use IG-490 with 350/403 cylinder heads, and IG-500 with 455 cylinder heads. M.P.P. also offers a
bolt-in Valley Tray to reduce manifold temperature, part number VT-580.
2. Apply Edelbrock Gasgacinch sealant, #9300, to both sides of the manifold as well as head surfaces. This procedure ensures a good seal.
3. Eliminate the end seal gaskets. Use RTV Silicone sealant instead. Apply a bead of sealant approximately 1/4" high across the block end seal surface,
overlapping the intake gasket at the four corners. This method eliminates end seal slippage and deterioration.


__________________

Fun71

Yes, I had the Performer 350 back then but now have the RPM (with no valley tray since it was installed in 2003). I am glad to hear the catalog description has been updated to reflect reality.

Again, I would just use an old turkey gasket for a valley tray.