283 experts

[Larry P.]

When I rebuilt my 283 I noticed the distributer went in a little to easy. I measured the shaft and I measured the distance to the slot and it would have been to short to drive the oil pump. I took it apart and took the oil pump back and they told me it must have been for a 57 chevy? As I remember, they replaced it and said something about extra pressure. I said fine and it fit.
Now here's the problem. I can't get the CC oil gauge line to stop leaking at the gauge and when it runs the preasure gauge is pegged, over 60 lbs?
Any pump made that would do that? Is there any other reason it would give a reading like that?
Getting frustrated,
Larry

[mike mccagh]

Re: 283 experts

distrib length of pass car 283 and vette 283 the same. so is the dimensions of the oil pumps off the two engines. they probably sold you a oil pump designed for the LT1 350ci 370 hp which has same dimensions size wise but will develope a higher pressure than a 57 283(pass or vette). your problem is the oil press line male fitting or the female fitting on the back of the oil press gauge. try replacing the male fitting on the end of the oil press line first. good luck, mike

[Mike McKown]

Re: 283 experts

They may have sold you an intermediate oil pump shaft for a '63-'67 V-8 Chevy II. They are a little shorter than the standard Pass car, truck or Corvette.

If you don't like that much pressure, you can change the relief valve spring in the pump. It's held in by a roll pin. You should be able to get one from your Chevrolet dealer. Ask for a standard spring, not SHP.

[mike mccagh]

Re: 283 experts

mike: why were the chevy 2 shafts shorter? mike

[John H.]

Re: 283 experts

Larry -

Sounds like they sold you a high-volume or high-pressure pump, neither of which are needed; all you need is a plain ordinary stock replacement pump. The leak at the gauge is probably a result of a worn male fitting; that's a GM proprietary design (not a typical compression sleeve fitting). Paragon has the line with two male fittings for about ten bucks, don't know if they sell just the fittings separately; photo of the male fitting on the right below.

[Mike McKown]

Re: 283 experts

The '63-'67 Chevy II's used a unique front sump oil pan, sump pick-up tube, oil pump and intermediate shaft. If you look at the Chevy II pump in car position, the pump driven shaft sticks up about a 1/2" higher to the main cap interface than does a regular civilian pump. Why this was done, I have no idea. The Chevy II shaft measures approx. 5.25" O.L., the civilian one approx. 5.75".

You can use either pump and related parts on either block. Just as long as you use the right combination.

[Larry P.]

Re: 283 experts

John,
That is exactly what I have from CC. Even if I have the high pressure pump, what should I expect to see as far as oil pressure? Sounds like I would be fighting leaks forever.
Larry

[Joe L.]

Re: 283 experts

Larry----

Of what year is the 283 block? It makes a difference. Some folks think that all small blocks are the same as far as the oil pump system goes. They're NOT. In addition to the 64-67 Chevy II difference that Mike mentioned, there were other differences. Most apply to early 265 and 283 engines. If you don't know the version of the engine you have, the block casting number should "tell-the-tale".

With that information, I think we can figure this out.

[John M.]

Re: 283 experts

Larry,
If your oil pressure line is the original one, the new fittings will not fit. The size of the oil pressure line of all the current available ones is larger and the fittings are larger as well. If the hex size on your fitting is 5/16", then you have an original, and will have to replace the entire line and all fittings if you can't get it to stop leaking. Don't pitch out that old line however, there are many of us who look for these lines forever! If you are having the car judged, I would consider having a new comperssion fitting made to fit your old line.

Regards, John McGraw

[Larry P.]

Re: 283 experts

I still have the original old line and fittings. The one I am having problems with, line and fittings, is from CC. The block is correct for a 60.
Larry

[Larry P.]

Got it!

I checked the line from CC and it would not stick to a magnet. found another steel line I had from something and I put the fittings on it and it worked, so far. I still have about 40 lbs when cranking and over 60 when running. Is there a downside to this? Should I change oil pumps?
Larry

[John M.]

Re: Got it!

Larry,
I would change out the spring to lower the pressure. It will probably not hurt anything, but will consume more horsepower and run more oil through the engine than necessary. If you ever PV the car, it will not pass with pressure that high.
Most of the repro lines being sold out there are of the larger diameter and are either copper plated or are copper lines. You do not want a copper line since it will work harden and break. The copper plated lines are being made since the current Judging Guide says it should be, but the JG is wrong! C2 lines are copper plated, but all original C1 lines were tinned bundy weld lines. This is just an example of specs from one year migrating to another.
The flats on the repro fittings are 3/8" instead of 5/16", and this is how most Judges identify the repro. If you take a Dremel tool and a sanding disk, you can turn the fitting into a 5/16" one and will quite likely avoid any point deducts. My original line was clogged and could not be cleared. The first time I had a repro judged it took a deduct for lack of copper plating and wrong size fitting. At my next 2 judgings, The flats were 5/16" and It took no deducts. By that time the judging team leader had agreed with my position that the line was not copper plated, after we looked at his original line and it was not plated! The size difference is pretty subtle, and will in all likelyhood slip by the judges as long as the fittings are the correct size.

Regards, John McGraw

[Joe L.]

Re: 283 experts

Larry-----

If the block is a 1960 block (i.e GM casting #3756519), then things are simple. You require oil pump GM #12555284 (current p/n) or the equivalent thereof. The Melling "equivalent thereof" is known as a Melling M-55. You do not want to use a Melling M-55HV or a Melling M-55HP.

If you have a Melling or Melling-equivalent M-55HV, return it and get the proper pump. If you have a Melling H-55HP, you can convert it to a Melling H-55 by simply changing the relief pressure spring to a GM #3814903.

The oil pump drive shaft should be a GM #3998287, or equivalent. This shaft is VERY common.

All the above applies assuming that some "tricky guy" hasn't replaced the rear main bearing cap with a 58 or earlier cap. That throws everything off. It's VERY, VERY doubtful that this has occurred.

[Mike McKown]

You have obviously left bait here

What happens if somebody did install a '58 or earlier cap on this block? You've got my curiosity up. I seem to remember something but I can't recall it. '58 the last year of the "rope" main seal? Like a lot of other stuff, I can't remember.

Also, left a little "bait" myself. I noted that '63-'67 Chevy II V-8's used a unique pump intermediate shaft. You commented they were '64-'67. Do you have any parts info on the dealer installed kit for the '63 Chevy II using the 360 hp/327 conversion? Part of it was released, or at least part numbers were assigned, in 1962.

[Joe L.]

Re: You have obviously left bait here

Mike-----

Actually, I was incorrect and I was going to post a correction. So, I'll post it here. It would not be possible to install the rear main bearing cap from a 58 or older 283 for exactly the reason you mentioned. The 1958 and older 283s used the rope seal and 59 and later used the neoprene seal. So, the 58 and older rear main bearing cap would not be compatible with a 59 or newer block.

However, IF one could have installed such a cap, then the the oil pump and shaft requirement of the later engine would revert to the requirement of the earlier engine. A different oil pump and shaft was used for 1957 and earlier engines and this requirement related directly to the configuration of the rear main cap.

The Chevy II oil pump difference was for the 1964-67 model years. For 1963, no V-8 engine was installed in PRODUCTION in a Chevy II. A 4 cylinder and 194 cid 6 cylinder were the only engine options. The V-8 was first installed in the Chevy II for the 1964 model year. In fact, that V-8 engine marked the very first use of the spin-on style oil filter on any Chevrolet V-8 engine.

If there was a conversion kit available for the 1963 model year, that would not qualify as a PRODUCTION installation. Conversions are conversions regardless of their genesis, GM or otherwise.