Diesel --> Towncar

[Archangel]

Castings are different, but internals are the same, to my knowledge. By the way, if the 6.2 vacuum pump is way back behind the intake, what turns it, the camshaft through a gear and input shaft like a gasser dizzy has?

[351m]

Camshaf does yeah, I was actually just looking at my haynes book today. Didn't even know GM used a belt drive one, all the 6.2s I looked at were Cam driven. It looks like the cam turns a shaft that has an eccentric on it that a pushrod rides against similar the the small block fuel pumps. I wouldn't be surprised if the belt drive pumps are identical though. I wish my scanner worked, I could upload the pic from the shop manual.

[Archangel]

Yeps, same setup as the belt-driven pumps, only instead of a pulley the 6.2 apparently uses a shaft. The one belt-driven GM vacuum pump I know for sure is Hummer-specific, which is sort of odd as the HMMWVs got a 6.2 at first and then the turbocharged 6.5, maybe it has something to do with the military-specific application?

[grandpaslincoln]

From what I've been reading a lot of folks seem to have problems with the pump keeping up with the needs of the brake booster and the anything else that needs vacuum, been reading that in some cases it takes 30 seconds to charge the booster back up after the brakes have been used. I know there were some double pumper diaphragm pumps made (I've seen them on Cummins motors, but those pumps are gear driven) I'm sure they can be found for belt drive systems too. I actually have a diaphragm vacuum pump in my basement from a Dodge, doesn't seem like it would pull much vacuum. Will have to wait and see I guess. I've been looking at electric vac pumps for applications where the cam is way too big to make vacuum, but those things aren't cheap ($200+). Maybe Ebay will yield some goodies.

Oooohh!

http://cgi.ebay.com/ebaymotors/Ford-...Q5fAccessories

Could still go hydroboost for the brakes (may have to anyway, judging by the size of the motor, the booster might be in the way) then use that electric pump to run everything else.

[Archangel]

Jon, the newer Superduty trucks all use hydroboost, the vacuum pump you found is only used to run the HVAC system, it can't pull enough vacuum to operate a brake booster. Stock vacuum pumps pull like 22" vacuum, and they're pretty good in the flow rate, I never ran out of vacuum with mine, besides you can always run a vacuum reservoir and be fine.

[351m]

Yeah, having run 4 Fords anywhere from '86 - '94, the pumps work just fine. My buddy had his '85 Gm with a 6.2 and a Muncie with a cam driven pump, but it had Hydroboost brakes so I have no idea how it would have kept up. that said My dad's cousin has a '78ish(could be newer, been years since I have even seen it) Chev crew cab with a diesel and vacum brakes and never had a problem.

[Archangel]

Well, since all vacuum diaphragm assemblies are the same on these old trucks, the only thing that makes for difference in flow (the amount of air the pump can move per given time) can be contributed to pump cam rotation speed - Chevy pumps run at about the same speed as the engine cam, which turns at half the engine speed, whereas Ford pumps being belt-driven are turning faster then the engine speed cause their pulleys are smaller than the crank pulley. So a Ford pump turns over twice faster than a Chevy pump, and therefore can move more than twice the air - no wonder why Fords have no issues keeping up with frequent brake applies.

[grandpaslincoln]

I'm thinking of doing the belt driven pump, just because of all the vacuum stuff. I think I can run a vacuum booster, maybe run the smaller booster, should fit in there on the firewall and not be in the way of the engine.

I know I've been posting more videos of other peoples 6.2's than my own, but I can't help myself and it gives me inspiration and shit lol

6.2 offroad buggy thing N/A open headers



Same rig with twin turbos added




Sounds like it was having some fueling problems at the end of the first video, having to goose the throttle to keep it running.

[Archangel]

Sounds like it was having some fueling problems at the end of the first video, having to goose the throttle to keep it running.

Actually sounds like the governor in the IP was trying to prevent an engine stall, happens when the idle speed is adjusted too low - you work with heavy machinery, have you seen a CAT do the same? It goes WOT for a few seconds, pretty darn scary when it does it to ya for the first time...

[grandpaslincoln]

Yeah I had it do it with an air cooled Deutz engine, scared the shit out of me lol

[inlinet18]

I only read a little (this seems to be a big topic) I hope you do it, I'd like to see 6.9/7.3 in it, but you have to use what you can afford. I wanna see how it turns out.

[Archangel]

we actually went over this already - the Navistar IDIs were medium-duty engines installed in light-duty trucks, they are big and very heavy and they use their own transmissions too - the 6.2 is lighter, revvs higher, and you can install about any GM trans behind it, so for a car that's a much better choice.

[dragginwaggin]

twin turboed newer 7.3 built something mild like 500-700hp 1000-1500 ft lbs dull 5" exhaust str8 piped dullie county squire with the wagion part turned into a bed it be like a el rancho grandie and you can cover that asshole tailgateing you in soot