3.0L Conversion: Belts -- Serpentine or V?

[jangell]

I noticed that the 3.0L engine seems to use serpentine belts. I'm wondering if I should use serpentine belts in my conversion, or if I should stick with the V belts from the 2.8L engine.

Pretty much all of my engine experience comes from the DeLorean, so I don't actually know that much about serpentine belts, beyond that there is a single wider belt that snakes through the pulleys rather than the two belts on the 2.8L engine.

I assume that if I decide to go with serpentine belts, I'll have to replace the pulleys on the A/C compressor and the alternator (and find a second idler; my engine only came with one). And if I stick with the V belts, I think I can use the 2.8L timing cover (so that the idlers will mount properly), the 2.8L's water pump (or at least the pulley) and the 2.8L's main crank pulley.

What would be the best way to go? Thanks!

-- Joe

[Bitsyncmaster]

The nice thing with serpentine belts is the spring loaded tension idler pulley. So belt tension is always correct with no adjustment needed.

[David T]

The nice thing with serpentine belts is the spring loaded tension idler pulley. So belt tension is always correct with no adjustment needed.

The best thing about serpentine belts is that you can use the back and the front of the belt to drive pulleys and because of the width you can run lower belt pressures and still transmit the same amount of power. Cobbling together the right pulleys can be expensive unless you can buy a kit and then you have to buy the exact correct size belt. Much easier (and cheaper) to do that with "V" belts.

[jangell]

I've seen some other 3.0 swaps that seem to have used serpentine belts, so I'm tempted to go that way. I want to convert my A/C to R134 (it's already leaked down and needs to be overhauled anyway), so I guess I can get a new compressor with the right pulley already on it. Then I'd have to find an alternator shop to do the pulley on the alternator. Maybe use a cloth tape measure (like they use for measuring clothes) to figure out the belt length? I plan on moving the alternator to where it is on the DeLorean, so I'll need a custom belt length anyway.

I'm a little fuzzy on the tensioner; since I just got the engine, I may be missing a few pieces besides the idler. There seems to be some bracket similar to the one that tightens the A/C pulleys on the DeLorean, so I expect that the missing pulley may be related to that.

Thanks guys!

-- Joe

[Josh]

I would recommend a newer serpentine belt setup. Here is what I did:

Buy new idlers (3) and install.
Use 3.0 a/c compressor
Use 3.0 waterpump (88-90)
Use 2.8 alternator with a swapped 6 rib pulley OR buy a 93-95 3.4 v6 camaro alternator. Both have the same CS130 casing.
Use a 6PK2120 belt

Everything is almost ready to bolt up... Now take the 2.8 alt bracket down to a machine shop and remove 9mm off the rear of the bracket as shown. You will need to use a longer bolt and a spacer (I used a bushing) to hold the alternator in position, which is also shown. Reinstall the old tensioner or opt for a new adjustable one.

[jangell]

Thanks -- I'll have to find a 3.0L A/C compressor (or an R134 compatible one... did they use R134 on the Premier/Monaco? Google suggests R12, but it's not entirely clear if that's true), although I expect that won't be overly difficult.

My engine is from an '89, so I have the right water pump. I was tempted to swap it with the fairly new 2.8L water pump I have, but it doesn't seem worth the trouble to swap the pulley.

Amazon shows the 105 amp Camero alternator (http://www.amazon.com/ALTERNATOR-FIREBIRD-CHEVROLET-10463624-10463375/dp/B007AMAVPU) for $75. Not sure how that compares to swapping the pulley, but it sure is convenient.

By "old tensioner", do you mean the one used to tension the alternator belt on the 2.8L, or some other tensioner on from the 3.0L?

You say you bought three new idlers; I only have one, and from pictures I saw where one other would go. Where's the third one go?

Thanks!

-- Joe

[Josh]

Thanks -- I'll have to find a 3.0L A/C compressor (or an R134 compatible one... did they use R134 on the Premier/Monaco? Google suggests R12, but it's not entirely clear if that's true), although I expect that won't be overly difficult.

My engine is from an '89, so I have the right water pump. I was tempted to swap it with the fairly new 2.8L water pump I have, but it doesn't seem worth the trouble to swap the pulley.

Amazon shows the 105 amp Camero alternator (http://www.amazon.com/ALTERNATOR-FIREBIRD-CHEVROLET-10463624-10463375/dp/B007AMAVPU) for $75. Not sure how that compares to swapping the pulley, but it sure is convenient.

By "old tensioner", do you mean the one used to tension the alternator belt on the 2.8L, or some other tensioner on from the 3.0L?

You say you bought three new idlers; I only have one, and from pictures I saw where one other would go. Where's the third one go?

Thanks!

-- Joe

I believe the premier uses r134. I haven't got around to a/c yet so ill learn that at a later date.

Good for the water pump. Since you have everything apart I would recommend you install a new pump as the history on the last one is unknown and these engines need all the help they can get in terms of cooling.

The alternators use the same casing so in terms of externals they are the same. So its up to you if you want to just get the alt or swap pulleys.

Yes I am referring to the original delorean one. None of the 3.0 related charging system is used (brackets, alternator, wiring)

One idler is on the passenger side as shown. the other two are on the drivers side downstream the a/c compressor. They are all the same part.

[jangell]

The water pump is still on the engine (I haven't needed to take the manifold or anything off yet), but I was planning on taking it off anyway since I'll have DPI's seal kit soon, and should probably look under the manifold anyway.

Amazon has a surprising number of parts for the Premier, including the A/C compressor (although I think it's the R12 model, ~$300), a few brands of water pumps ($50-$150), and the idler pulleys (~$20; didn't notice the spindle they mount on, though). Unfortunately, their search doesn't search based on the car you chose; you have to manually walk through the list of car parts in their Part Finder, which is annoying.

For the tensioner, I guess this means that the alternator tensioner is used to tension all the belts then?

Thanks again -- I'm hoping to clean up all the mating surfaces this weekend in preparation for re-assembling the engine next weekend.

Incidentally, I stumbled onto this service manual (http://www.pirate4x4.com/tech/billavista/PDFs/New%20Jun%202003/Sanden%20SD%20compressor%20service%20manual.pdf) for the A/C compressor that Amazon referenced, a Sanden/Sankyo Sd709. The manual includes information on how to determine compressor details from the model number, including R12 vs R134.

-- Joe

[Josh]

Correct, the alternator tensions everything.

Also I highly recommend purchasing parts from Rockauto.com

[jangell]

Thanks -- they're prices seem better than Amazon's, too, and it's easier to find what I'm looking for.

A couple other quick questions:

- The warranty for the engine said it's only valid if you also replace the timing chains (among other things). The engine has 36k miles on it; should I bother? I obviously don't care about the warranty, which has already been voided since I didn't have pros install it in the original car model within 10 days or whatever it was.

- What do they call the thing on the passenger side valve cover that, on the DeLorean's driver's side valve cover, would be called the Oil Filler Assembly (DeLorean part 102415)? The 3.0L has a separate twist-on cap to fill the oil on the driver's side cylinder head that's referred to as the Oil Filler Cap, so it's not that. I accidentally crushed this piece while tightening the ratchet straps to hold it into the bed of a pickup truck, but I can't figure out what it's called so I can get a replacement. I'm also wondering if I can just use the 2.8L one, but the internals seem different (the 2.8L has some kind of screen, while the 3.0L has a spiral), although I'm not sure that matters.

- Does anyone know what size the freeze plugs/core plugs/whatever are on the cylinder heads? Some googling found that they're pretty easy to replace, once you get the right size. The seller marked a bad one in the notes on the front of the cylinder head. I expect these are the same for the 2.8L and 3.0L

Thanks!

-- Joe

[Josh]

Thanks -- they're prices seem better than Amazon's, too, and it's easier to find what I'm looking for.

A couple other quick questions:

- The warranty for the engine said it's only valid if you also replace the timing chains (among other things). The engine has 36k miles on it; should I bother? I obviously don't care about the warranty, which has already been voided since I didn't have pros install it in the original car model within 10 days or whatever it was.

- What do they call the thing on the passenger side valve cover that, on the DeLorean's driver's side valve cover, would be called the Oil Filler Assembly (DeLorean part 102415)? The 3.0L has a separate twist-on cap to fill the oil on the driver's side cylinder head that's referred to as the Oil Filler Cap, so it's not that. I accidentally crushed this piece while tightening the ratchet straps to hold it into the bed of a pickup truck, but I can't figure out what it's called so I can get a replacement. I'm also wondering if I can just use the 2.8L one, but the internals seem different (the 2.8L has some kind of screen, while the 3.0L has a spiral), although I'm not sure that matters.

- Does anyone know what size the freeze plugs/core plugs/whatever are on the cylinder heads? Some googling found that they're pretty easy to replace, once you get the right size. The seller marked a bad one in the notes on the front of the cylinder head. I expect these are the same for the 2.8L and 3.0L

Thanks!

-- Joe

It is a good idea to replace the chains, tensioners, and oil pump chain while everything is apart. But if you are sure the engine has that low of milage they should be fine. But that is very low mileage.

The part you are refering to acts as the PCV valve. For the 2.8 it acts also as a filler cap (which i think is silly) and the other valve cover has no provisions for anything. With the 3.0 the PCV and filler cap are separate, just like most engines. As for interchangeability I dont see why you couldnt use either so long as it securely fits in the tube. You can also install the 2.8 valve covers on the 3.0 but this requires some machining to the internal ribbing as they interfere with the valvetrain.

Not sure about the freeze plugs. I do have a shop manual for the premeir so ill take a glace at it and see if I come up with anything. The block (upper crankcase) is the same between the 3.0 and 2.8, all prvs shared the same block. Other things changed like the lower crank case, heads, cylinder sleeves, etc

[jangell]

I was hoping to be lazy about the chains/tensioner, mostly because I'm a bit fuzzy on how to replace those parts. This engine was by far the lowest mileage one I found (most were 90k miles). Unless the Premier only has 5 digits on its odometer and it looped around. :)

Thanks for the info on the PCV. I don't have anything like a parts manual for the 3.0L, so I have to rely on the DeLorean parts manual, and there's enough differences to make that tricky.

For the freeze plugs, I figured that at worst I can pull the bad one and measure it with calipers, or bring it to an auto parts store and see what they came up with.

Also, bitsyncmaster mentioned that serpentine belts have a "spring loaded tension idler pulley." I gather that if we're just tensioning with the alternator bracket, we're not going to have that?

Thanks!

-- Joe

[Josh]

Yeah he is correct with the automatic tensioner application. It replaces one of the idlers but there are no provisions for one on a prv. I do see myself retrofitting one in the future though, I think it is do-able.