500 Caddy/Monte Clip into El Camino

[dogsht]

Just some thoughts. An in-tank electric is far more reliable & safe than an out of tank electric. The Walbro I suggested I have used for 10+ years and its what comes in a new Vette. I have peace of mind with the two I have used, one in my GN the other in my 509ci Caddi powered Q-jet 442. I have not lost any sleep in out of state trips. I have put 9,000 miles on the Walbro Mallory Q-jet Caddi with not so much as a hickup. Many more on the GN. A mechanical plus an out of tank electric seems very inefficient power / fuel consuming and more places to track down troubles to. Maybe I am entirely off base just my way of thinking. The limited fuel pressure adjustability would still bother me. Also would a pressure guage in line before the carb give an acurate reading with this setup? Not saying it won't just that I am not sure. The first Cutlass that I put this setup on I mounted the fuel pressure regulator as they suggest on the corner of the intake with maybe 5" of fuel line between it and the carb so not much fuel to heat soak between the constant flowing fresh supply at the regulator and the carb. The second car the 442 I mounted the regulator down out of site on the frame either way no heat issues. Also I used the Edelbrock aluminum intake and blocked the hot coolant passage under the carb base as the electric choke carb really doesn't need it. I can see wanting the 22 gallon tank over the 17- 18 gallon tank. Wish you the best regardless of which way you go. BTW my thoughts on reliability and power are the same as yours which is part of why I chose the Caddy. Big power/torque on stock over the counter parts without being stressed or spun hard like a sb would be to do the same job. A stockish well tuned Cad 500 will make more torque at 2,000 rpms than a well built 350 at 3,500. No need for a big heat big slip stall converter no need for crazy gears to move the weight quickly no need for a big cam with big spring pressure and high dollar valvetrain components to keep it alive under stress and while haveing the snot spun out of it.

I am sure you know good cooling system setup but some things I have learned and some Cad specific or sensative. Take extra effort to make sure you clean your block coolant passages well. You may need to chissel some of that crude out. Seems to be a Cad problem and people try to make up for it other places and have a hard time. A clean cooling system is far more efficient at transfering heat. I have had real tangible results with RMI-25 at keeping your whole cooling system clean lubricated and properly PH balanced. On www.cadillacpower.com and Potters pictures there are pics of them tapping the back corner of the drivers side head to run a cooling line over to make the cooling system flow better. I never got it done but I am told and its logical that it helps an on the edge of detonation engine especially. Naturally any cooling system improvement is good even if its not necessary. I used two high powered electric but you can also use a good 7 blade clutch fan. Make sure shroud is placed half way in the blade for best suck. A vented engine bay helps. I could actually tell the difference in underhood heat when had my headers coated. You can see in my pics that my intake air is all fresh air sealed from the hot engine bay heat. Use a Cadillac specific thermostat they are different. Last a good headered engine oil cooler is a most undervalued longevity plus engine cooling upgrade. Oh yea for some good pics on fuel system etc plus check out www.robertpowersmotorsports.com Lots of good pics ideas and info. Check out his tech info on the fuel system, engine oil cooler, transmission & rear end.

 

[Doober]

Looks like you've made some progress since I was last able to check the forum, sweet 😀

We just got into Tucson today, came in on I-10. Things will probably be fairly hectic the next week & a half, looking at a house tomorrow, and after she finds a place we have a 24' box truck to unload, plus I'm looking for a place to start work (may transfer to one of the Tucson Best Buys, I'm not sure yet) as well.

This is only my 2nd time ever in AZ (my first time was when I was 17, about 10 years ago :shock🙂, so I definitely have some adjustment as far as the lay of the land/climate goes :lol:

 

[Mike P]

Yeah Darren I got a little done, I'm just kind of setting up the little stuff right now. As you can see Vern and I spent most of last weekend discussing fuel systems :lol: I don't think either of us will completly comvince the other but the nice thing about these forums is the ability to exchange ideas.

Probably not going to do much on it this weekend, I've got the wife's El Camino in the shop.....upgrading the TH250 to a 350.

Welcome to AZ....land of rust free sheetmetal and sun rotted interiors. On the bright side it should start cooling off on in a month and a half or so. Did you bring the Malibus down?

 

[dogsht]

Mike I did think you would address my last post but it ok if you don't. Only real question being would a pressure guage work accurately in your setup? I am really not trying to be argumentative. I know the factory type setup I use works properly and I am not saying the setup you have designed won't. I am just questioning and seeing if there is any reason not to do it that way and or if there are any benefits of doing it that way. The other info I just thought you might find useful. All the best on your project & sorry if I offended you.

 

[Mike P]

No Vern, you did not offend me (I’m, sorry if I gave you that impression), and I'm sorry about not replying to your question earlier. You provided some very good input and another option that might work equally as well. It just seemed we were going back and forth re-explaining or respective positions over and over.

I usually don't install a gauge unless I'm trouble shooting a system. When I have done this I've found that an accurate reading can be obtained anywhere between the mechanical pump and restrictor (provided there is not restriction between the gauge and the carb inlet) however the closer you get to the pump the more chance of reading the pump pulsations. If I need to check pressure on this system I would probably put a T fitting instead of the 90 degree elbow into the carb and take the pressure reading from there as it will show exactly what is at the needle and seat.

In the same light (and not to be argumentative) as far as the safety and reliability thing you raised, I locate my supply pump in front of the tank up on the frame (not behind the tank). It’s as safe as any other system. As far as reliability the last time I used this type of system I did have to replace 1 electric pump at about 75K miles, but due to the redundant pumps it did not leave me walking.

There are 2 main problems I have with in-tank electric pumps. Unless the normal design has changed they are positive displacement meaning that if they fail they don’t pass fuel, there is no roadside work around, you are stopped until you drop the tank and replace the pump. The thing that normally kills the pump is heat, and one of the things that causes the pump to over heat is running the tanks low enough that the pump is no longer submerged. Around town it is usually not a problem to keep at least 1/2 a tank of fuel and even if you run the tank low the trips are generally short so the pump does not have time to build a lot of heat. On a long road trip however, I usually don’t start looking for a station until I hit 1/4 tank of fuel, meaning the pump will have a chance to run hotter longer. Don’t get me wrong I’m not saying the in tank pumps are inherently bad or un-reliable (people drive cross country with them every day) they are a lot bigger PIA to replace if you have to.

Would I ever use an in-tank pump, sure I would. I actually think that for the fuel demands if/when I build an E85 only engine it would probably be the way to go due to the higher fuel demands. It’s just not for this project.

 

[Doober]

I haven't brought the Malibus down yet, I'm on my 4th night in a hotel, my aunt's in the process of a major life change, and I'm going to give the change a shot as well, so long as I can find a decent job (I'll be living with her & my two cousins, at least for a while). I don't have place for storage (didn't have the means to get them here either), but my parents are planning on making the move within the next couple years as well & my dad has a '38 Chevy pickup that will be coming with them. My plan is to probably fly up, migrate the parts I'll be able to use from the '81 to the '78 (pretty much all things mechanical) and trailer it, then work on it down here.

 

[Mike P]

Re: 500 Caddy into El Camino

There hasn’t been a lot going on with my project, I’m still waiting to get a good title on it (the state seems to be taking a bit longer than usual on this one). I’ve been doing some little stuff and collecting some more parts, but that’s about it

Looking over the 500/G Body swaps I’ve come across, most indicate there is an issue with the front sump and drain plug sitting directly above the crossmember. Depending on the builder, some of have the engine sitting to low to access the drain plug and have eliminated the front sump, others are high enough to get to the plug but it then drains directly onto the crossmember and some had cut and welded a channel into the axel relief between the 2 sumps. I had a spare Eldo pan laying around so I decided to see if I could use some heat, a length of pipe and a big hammer to make a drain trough. I think it worked out pretty well.

I normally leave the exhaust until much later in the project and up until the last couple of years would usually sent it to a muffler shop. As some of the local shops have closed or changed hands the quality of the remaining shops has gone down and the prices up, so lately I have been building my own systems or buying pre-bent pipes when they are available. I came across what I thought was a pretty good deal on a pair of 2 1/2 “ G Body tail pipes. After reading some discussion here and seeing pictures of the fit of the Pypes X Pipe for the G Bodies, I went ahead and picked up one of those also. I will actually need the X pipe for mockup so I know where to put the exhaust reliefs in the crossmember I’ll be building. Depending on clearance issues I may have to include some ball and socket joints in it to allow the X Pipe to be dropped out for drive shaft or transmission removal, but we’ll see when I get to that point.

 

[brian]

Re: 500 Caddy into El Camino

looks like fun, What I did on an eldo pan is wrap a piece of sheet metal around the high spot and weld it in then cut out the high spot from the inside with a zip disc. As long as it can drain back fast enouigh that the sump doesn't run dry! Are you going to be running factory manifolds? If so you will likely have to cut a notch out of your cross member on the drivers side as well, unless your motor is mounted really high. good luck
Brian

 

[Mike P]

Re: 500 Caddy into El Camino

"......Are you going to be running factory manifolds? If so you will likely have to cut a notch out of your cross member on the drivers side as well......"

The plan right now is manifolds and looking at other peoples builds have kind of resigned myself to the possibility (probability) of having to do the notching.

 

[Doober]

Re: 500 Caddy into El Camino

I had good luck getting the Pypes system in my Malibu. Pretty much everything slid right together... I bought a full header-back system though. That system included a ~15" pipe that's supposed to connect to headers, but I'm guessing you'll be putting a set of cats on this one. I like the sound of the mufflers that were included as well (Pypes RacePro, straight-through design).
http://www.youtube.com/watch?v=GhN7NHru--Y

I'm still out here in AZ, getting a little more familiar with the area, we're up at the north end of Tucson in Oro Valley.