Leece-Neville Or Delco:

[Rob]

My 1980 R model has a L-N alternator and most of the othe trucks use a Delco 25si series. Nothing wrong with the Delco units other than the pull in rpm is very high before they start to charge. The L-N starts to charge as soon as the engine is turning. What I mean is if you don't rev the engine to about 800-1250 rpm, the Delco units do not start charging, where the L-N does not even require a foot to be applied to the accelerator to start charging. This must be normal for the Delco units as all four of them do this although the rpm's to start charging vary. My 74 RL has an external regulator type L-N and it performs like the Delco units, but does work well.

I'm wanting to replace the external voltage regulator type on the 74 RL with an internal regulator type alternator. From the field I'm asking which is a better unit? I've really had no experience with either on the road.

Rob

[bullhusk]

I would pick the one made in the USA if there is one?? But in 1987 my R Model's had the LN an I wound up switching over to Delco after changing them a few times, but your talkin about trucks workin every day an pumpin cement

Ernie

[bobo]

I hate L-N as much as wilson starters! GO WITH THE DELCO! up here we buy alt's and starters from the either Mack or Sterling/FL dealers, the cheapest around and not off shore junk! b0b0

[rhasler]

My 1980 R model has a L-N alternator and most of the othe trucks use a Delco 25si series. Nothing wrong with the Delco units other than the pull in rpm is very high before they start to charge. The L-N starts to charge as soon as the engine is turning. What I mean is if you don't rev the engine to about 800-1250 rpm, the Delco units do not start charging, where the L-N does not even require a foot to be applied to the accelerator to start charging. This must be normal for the Delco units as all four of them do this although the rpm's to start charging vary. My 74 RL has an external regulator type L-N and it performs like the Delco units, but does work well.

I'm wanting to replace the external voltage regulator type on the 74 RL with an internal regulator type alternator. From the field I'm asking which is a better unit? I've really had no experience with either on the road.

Rob

Hi Rob, I think the Delco are usually lower in price. I've seen problems with the Leece alternators on newer trucks overcharging and burning out sensitive electronics on a few occaisions, something I haven't seen happen with the Delco. The Delco on the other hand seems to have a higher rate of replacement, but that could be just a matter of them being used more commonly. Keep in mind this is on newer chassis with quite a bit more electrical apparatus drawing power and with higher heat rejection from the engine.

[Rob]

I have an "extra" 25si Delco with unknown condition, and an L-N on a spare engine. I know nothing about this one either but it is on a very good running E6-350 I bought out of a wrecked Western Cruiseliner truck. This engine also has a L-N starter. Either one would go through rebuild before use and the shop I use does not use the offshore stuff in their rebuilds. They really don't want to see the unit again. A little more expensive but I've never had problems.

Thanks,

Rob

[b61mack]

My 1980 R model has a L-N alternator and most of the othe trucks use a Delco 25si series. Nothing wrong with the Delco units other than the pull in rpm is very high before they start to charge. The L-N starts to charge as soon as the engine is turning. What I mean is if you don't rev the engine to about 800-1250 rpm, the Delco units do not start charging, where the L-N does not even require a foot to be applied to the accelerator to start charging. This must be normal for the Delco units as all four of them do this although the rpm's to start charging vary. My 74 RL has an external regulator type L-N and it performs like the Delco units, but does work well.

I'm wanting to replace the external voltage regulator type on the 74 RL with an internal regulator type alternator. From the field I'm asking which is a better unit? I've really had no experience with either on the road.

Rob

I like the old Motorola built by (Prestolite) i think Leese-Neville bought them out Mod.# 81HA2070VB, the tag on mine says ( made in USA by Prestolite }, i had better luck with those. where i work they put on a new Delco lasted about 1 month( made in china } ended up putting a new L-N no problems Ron

[41chevy]

If you want the Delco to charge at a lower rpm , change the pully down to a smaller diameter. I recall a 15% undersize will kick the charge in about 600 rpm . Paul

[leversole]

If you want the Delco to charge at a lower rpm , change the pully down to a smaller diameter. I recall a 15% undersize will kick the charge in about 600 rpm . Paul

If it (the Delco) has an internal regulator, and is anything like the 10SI internally, when it "kicks" in is based on the resistance in the the circuit that runs from the keyswitch through the "idiot" light, you can put a small resistor, or bigger bulb, to make it kick in sooner and start charging at a smaller rpm...the one I have (10SI) doesnt start charging until it reaches about 800 rpm, but after starting, I just blip the throttle, and it kicks in, charges, and stays charging even it idle (550rpm).

[41chevy]

If it (the Delco) has an internal regulator, and is anything like the 10SI internally, when it "kicks" in is based on the resistance in the the circuit that runs from the keyswitch through the "idiot" light, you can put a small resistor, or bigger bulb, to make it kick in sooner and start charging at a smaller rpm...the one I have (10SI) doesnt start charging until it reaches about 800 rpm, but after starting, I just blip the throttle, and it kicks in, charges, and stays charging even it idle (550rpm).

I wasn't thinking of the I.R. unit. Mine all have and external regulator not the internal.except my AC which now has a Hitachi in the generator case....but the increase in alternator RPM with the smaller pully sends a false signal through the regulator circut. Telling it the engine speed and demand is higher then it is. Like blipping the throttle.