Spitfire Crank Endfloat and Oil Pumps - Spitfire 1500

[dklawson]

I'm going through an internal exam of the donor 1500 that will be taking the place of the 1300 in my project '72 Spit.

The crank endfloat is measuring 0.008". I believe that's at the upper end of the limit. Can I slip new thrust washers in without pulling the crank? If so, is it possible to pin them or otherwise secure them without pulling the crank and where would I find information on that process?

The oil pump looks to be in better shape than I'd hoped. There is little to no scoring of the lobes or rotor and the pump endfloat is about probably about 0.003". The existing pump is an angled head type. I have a brand new straight body pump. I was considering putting the new pump in with the angled pickup head. Am I correct that there is no problem with that? On other cars I've had it was beneficial to have as little as 0.001" oil pump rotor endfloat. Is it worth removing a bit of the pump body height to minimize the pump endfloat before I install it?

Thanks in advance for the advice.

Doug L.

 

[aeronca65t]

0.008" isn't too bad. But if you're working on it anyway, it's a good time to replace the thrust washers.

I've heard both schools of thought on pinning them. I think, if you're the type of person who really lets your car maintenance go, pinning might be a good idea (so they don't fall into the sump). For those of us who keep an eye on things, I personally feel it's unnecessary. It's easy to check end float on the crank.

The thrust washers in my racer are not pinned (I change them about once a year).

The side plate on my oil pump had a bit of wear allowing some end float. I put some fine grit paper on a piece of glass and worked the plate back and forth on the paper until it was decent. I'd estimate it took me two beers-worth of time to get it pretty smooth. :laugh:

I forget the deal on the angled oil pump head, but I *think* that's for 1500 Spitfires only. 1500 Midgets and 1500 Spits have different oil pans and the pickups are different as a result. Maybe someone else can jump in here and provide better info (it's been a while since I did this....my Midget has a Spit engine and I kind of recall that the angled pickup didn't sit deep enough in the Midget pan).

 

[dklawson]

Thanks Nial.

The engine was given to me by a friend who took it out of a car he totalled. He assured me the engine was strong but I really wanted to open it up and check the condition of a few things before installing the engine. On the other hand, I wasn't interested in starting a complete rebuild either.

In addition to replacing the thrust bearings I'm also considering replacing the mains and rod bearings just because it's a good time to do it. It looks like the crank is 0.010" under on both the mains and rods. I had no idea there would be at least three types to choose from with at least as many different vendors. I've come across shells just listed as "bearings" then I've come across bi-metal and tri-metal bearings. Since I'm working on a street engine is there any advantage to going with the dual or triple material bearings?

If I do replace the thrusts I found that they are also in "sizes", typically steps of 0.005". I haven't found what the standard thickness thrust washer is yet to know what I need (if anything). Does anyone have a thickness spec for a 1500's standard thrust bearing?

 

[booley]

wasn't the purpose of the angled pickup to just move it towards the center of the pan? the oil could move away from the straight pickup in a hard corner...

aren't vandervells suppose to be the best bearings?(if you can find them)

 

[aeronca65t]

I *think* the standard thrust washers are 0.090" thick (again, maybe someone else can come in here and verify that).

If I get a chance I'll look at my old ones and see it that makes sense.

Absolutely change rod bearings! They are are weakest link in the 1500 engine.
If the main bearings look OK and you don't feel like really pulling everything apart, you can probably run the old ones.

 

[Tinster]

I *think* the standard thrust washers are 0.090" thick (again, maybe someone else can come in here and verify that).

I think the .090" is correct stock. Order a set of stock
and also a set of .005 oversized. They cost little money.

Try different combinations, measuring endfloat as you do.
Once you get a combination that is close to spec., you can
use a glass plate and 800# grit wet paper to "shave" .001
or .002 off the BACK side of one of the TW to attain
dead-on spec. DON'T shave the oil grooves side!

hope this helps,

tinster

 

[dklawson]

Thanks for the additional input.

The angled pump was what was on the engine when I removed the pan so I assume it would be correct. I have lapped the mounting surface of the angled pickup head as Nial suggested and will use it with the new pump assembly.

The main bearings did look good so I will use them as they are. The rod bearings looked... well... a little scuffed. That's the best way to describe their appearance. Their wear surface was darker grey and had some minor abrasive marks on them. However, both the crank's main and rod journals look very good with no marks at all.

It has been 16+ years since I bought bearings for the GT6 but at that time I believe Vandervell bearings were the ones to have. I did not see these listed by name at the usual parts suppliers. However, BP Northwest's tri-metal bearings are listed as being of the same composition and construction as the Vandervell bearings. I'll add them to my parts order.

Dale, it's been a while. Thanks for your advice on the thrust bearings. At this point I'll pull the lower half of the thrust bearing and measure it. Then I'll have an idea which I'll need. I'll modify the thickness as necessary to achieve the desired minimum endfloat.

Thanks again all.

 

[Tinster]

There are two thrust bearings and they ride on the top side
of the crankshaft with their oil slots facing away from each other.

Here's what a thrust bearing looks like being
"shaved" down 0.002"

Here's a Thrust Bearing as it would be installed wrapping
the top of the crankshaft. Again, oil grooves face away from each other.

Here is a photo of the engine upside down with crank removed.
This shows you where in the block the Trust Bearings are located. The crank does NOT need to be removed to install TBs..

Your quess Doc!

 

[MDCanaday]

I would NOT go to the 1500 since the 1300 made as much power with better reliability.Plane the 1500 head to get the same cc in the chamber. Get Kastners book so you dont re-invent the wheel.STD GT6 pistols are 1mm over stock bore and cheap.Nicely balanced and cammed this 1350 makes for a blast to drive and wont jamb a rod out the side of the block if you rev it up!!! In any case a 1500 without a fresh lower end is only good for a few miles....(IMHO)
MC(mad dog)

 

[dklawson]

After re-reading the endfloat specs and re-measuring what this engine currently has, I will leave the thrust washers alone. The specs call for 0.006-0.014" and I measured 0.008" so this is an area I won't touch. However, the rod bearings will be replaced. I found a very good web page discussing the bearing types. Several sites confirmed that on the 1500 the mains can easily outlast the rod bearings.

See here:
https://visn2.com/Flash%20Website/1500_Replacing_Main_and_Rod_Bearings.html

MC, thanks for the advice, however, the 1300 I have removed from the car is in need of a complete rebuild. It is not my intention to invest the time or money at this time rebuilding the 1300 (or the 1500) when the 1500 was given to me for free in running condition. I am investing the time to inspect and address a few areas prior to installing the 1500, but I'm not rebuilding it. As mentioned above, the mains and thrusts appear to be in good shape and it appears replacing the rod ends will be sufficient for now. Again, thanks for the advice but rebuilding either engine is not in the cards at this time.