What makes these trucks destroy distributor caps/rotors?

[evilunclegrimace]

United Motor Products;
5.0 & 5.7 engine,DCR820X vented cap includes rotor. Brass contacts. $29.79
4.3 engine,DCR66X vented cap includes rotor.
Brass contacts. $27.79
Info from Rock auto.

 

[99xcss4]

United Motor Products;
5.0 & 5.7 engine,DCR820X vented cap includes rotor. Brass contacts. $29.79
4.3 engine,DCR66X vented cap includes rotor.
Brass contacts. $27.79
Info from Rock auto.

the dcr820x is also for the 454 right?

 

[L31MaxExpress]

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[L31MaxExpress]

The little plastic vent dome on those caps is pressed on to a vacuum nipple, hook up a vacuum vent system as shown. Each piece has a function. Check valve keeps fuel fumes out of the distributor for obvious reasons. Filter ensures no dirt or contaminantes enter or restrict the orifice or check valve or find their way into the engine. The orifice has a small metered hole to restrict the flow and prevent the system from being too large of a vacuum leak. Small amount of air purging through the cap all the time makes a big difference in preventing ozone buildup and corrosion from the ozone buildup. Vans and SUVs already have one port of the PCV adapter taken for the HVAC system. The Dorman PCV cap has dual smaller fittings allowing for the distributor vacuum venting system to be added without affecting the use of the other port. Trucks with air injection will already have both ports and both in use.

 

[Scooterwrench]

The little plastic vent dome on those caps is pressed on to a vacuum nipple, hook up a vacuum vent system as shown. Each piece has a function. Check valve keeps fuel fumes out of the distributor for obvious reasons. Filter ensures no dirt or contaminantes enter or restrict the orifice or check valve or find their way into the engine. The orifice has a small metered hole to restrict the flow and prevent the system from being too large of a vacuum leak. Small amount of air purging through the cap all the time makes a big difference in preventing ozone buildup and corrosion from the ozone buildup. Vans and SUVs already have one port of the PCV adapter taken for the HVAC system. The Dorman PCV cap has dual smaller fittings allowing for the distributor vacuum venting system to be added without affecting the use of the other port. Trucks with air injection will already have both ports and both in use.

So that puts a little oil vapor into the dist.?

 

[L31MaxExpress]

So that puts a little oil vapor into the dist.?

Not that I have seen. In that setup the vents are still in the bottom of the distributor base. Adding the filter is more preventative, GM had a filter on the vented optisparks too, so I took the same play from their playbook. Mine has the GM LT1 optispark vent kit that was available and inexpensive 15 years ago. What I drew up does the same basic thing. On my L31, I drilled and tapped the vents on the base, added a 90* hose barb fitting to each, 1 line to the OE air intake duct off the air cleaner behind the MAF, 1 line to the vent system and RTVd the cap to the base. The way thebabove system is setup is just easier if running a vented cap anyway. I wanted to make sure idle fueling would not be thrown off when I first did mine and at the time nobody made a vented cap, however I later discovered that it makes practically zero difference even at idle with that tiny orifice in the hose.

 

[Scooterwrench]

Not that I have seen. In that setup the vents are still in the bottom of the distributor base. Adding the filter is more preventative, GM had a filter on the vented optisparks too, so I took the same play from their playbook. Mine has the GM LT1 optispark vent kit that was available and inexpensive 15 years ago. What I drew up does the same basic thing. On my L31, I drilled and tapped the vents on the base, added a 90* hose barb fitting to each, 1 line to the OE air intake duct off the air cleaner behind the MAF, 1 line to the vent system and RTVd the cap to the base. The way thebabove system is setup is just easier if running a vented cap anyway. I wanted to make sure idle fueling would not be thrown off when I first did mine and at the time nobody made a vented cap, however I later discovered that it makes practically zero difference even at idle with that tiny orifice in the hose.

Yeah,probably less than three steps subracted from the IAC.(ha-ha guys,got it right this time).

 

[Scooterwrench]

I wonder if the old coil in cap CCC distributors of the early 80's could be used in our trucks? Anybody ever tried it? They were just as tough as the mechanical advance HEI's but with ECM timing control.

Hey Max,What's your thoughts on this idea?

 

[L31MaxExpress]

Hey Max,What's your thoughts on this idea?

It is too large to fit behind the manifold. A small cap TBI/TPI HEI EST barely clears. I have run the CSFI Vortec injection with both a TPI and TBI ECM.

 

[Sean Buick 76]

Which engine are you looking for?

Mines a TBI 350