Bottom End Wear - Engine Out Job

[jonclancy]

Evening all,

I now have a block and a pile of bits!

The oil pump is utterly destroyed! I'll post a couple of pics later, but it's a sight to behold. The rest of it looks pretty damned good, considering. Anyway, I'll be taking it all to be checked and rectified next week - diary permitting.

Just goes to show what a strong little engine the A-Series is.

[jonclancy]

Here we are...

The full pic collection is here:

http://s94.photobucket.com/user/jonclan ... t=3&page=1

[Westfield 129]

Those pumps are usually pretty stout. It must have ingested something...

If the crank journals are OK (of proper dimensions, and able to take a polish), you will still need to remove the main oil gallery plugs so that the block can be properly cleaned and flushed. Then the galleries are threaded, and pipe plugs installed. This will ensure that all that metal wont be fed to your new bearings. There really is no way to properly clean the galleries without removing the end plugs.

I have not had to de-coke an engine for, well, ever. I found that some fuel system additives that promised to "clean combustion chambers" actually work, rewarding clean piston tops and chambers after pouring a bottle in the fuel tank. I used a borescope to check the results in my heavily cartooned 948 A series a couple of decades ago. The stuff works! It took only a single bottle in the 6 gallon Lotus 7 fuel tank to clean out the old A series.

I am going to order a new oil pump for my old 1380...

[erictharg]

My oil pump looked similar when my last cam wore away the first two lobes to practically nothing. Last time I use a re-profiled cam! Recommend you choose a cam on a new blank for your rebuild Jon (I'd guess you owuld anyway). And lots of assembly lube on the lobes and the followers. I used Graphogen last time and it seems to have bedded in fine (touch wood).

[Westfield 129]

I have used re ground cams, and new billets. Usually I choose new, but my own engine has a re grind, and has over 20K miles on the APT reground scatter pattern race cam. As I have had minimal need to adjust the valves, I figure that the cam is doing fine. The power output of the engine remains, stout as well, and there is no metal in the oil (so far...).

I agree that a fresh cam is better, but if the new billet is not properly treated after grinding, it is no different than a re grind. Also, it is important to check the valve train geometry if the head has been milled (my latest Longman required .030 shims to get the roller rockers back where they belong). Occasionally, incorrect geometry flattens the cam lobes. So does a lack of sufficient cam lube, and incorrect pushrod length. Even a mild cam might require a different suite of valve train parts.

It is amazing how many engine builders will let geometry errors slide, and don't notice the rockers hitting the valve springs/retainers. My first engine (the one that came with the car) had this problem. I found out about it after the sintered rockers started breaking... I corrected the problem when I rebuilt the engine to its current specifications.

The lesson is to always choose a cam by a reputable cam grinder/supplier. We have quite a few here in Southern California, and I am sure that there are several in the UK. I am also sure that your cam grinders will alert you to any geometry problems if you give them the cylinder head measurements and the rocker type you are using. Shims are cheap, and can really help with the power output and longevity.

I am planning to build another short block assembly in 1380, with a hotter cam and 7 port head. That cam will be ground on a fresh billet. Maybe it will be dry summed.

[erictharg]

The valve train is the most highly stressed part of most engines, and the A Series is no exception,especially when increasing lift for performance. It's always going to be marginal, so anything you can do to help it make it ("...though the night" te tum) has to be good.

[jonclancy]

Yep-I was looking at new blank, followers eitc. I am hoping the bores are in spec and reuse the pistons, as they have less than 3K on them. Bearings will of course be refreshed. It's all worthwhile experience gained. I'm hovering between assembling myself and p(r)aying. Budget limitation might mean it's me...

[erictharg]

Give it a go. A series is straightforward to build. Stick to the book and you'll be fine. Save you a ton of money and be very satisfying when its done. And unless you got to someone with a good track record (and therefore expensive) you'll never know how good a job they do.

[jonclancy]

Update:

Original crank will need a grind as it's a few thou worn (with surface marking). Not a problem, and it'll be a 030/030 item when done. Hardening as desired/required.

The good news is that my spare crank is std/std and pretty much bob-on. It'll just have a polish and std shells. Pistons etc look good. Flywheel will get lightened and have a new ring-gear fitted. The whole lot will be balanced.

The bores look ok. The block will get de-bunged, a hot bath and pull-through with a flaming duffel-coat. The head is going to get a mild gas-flow and we're looking to get an uprated cam. Rob suggests a Piper 270.

Finally, we're going to revert back to a stock sump. I'm reluctant to put the project sump back on until it is absolutely certain that it wasn't the source of the contamination that got into the engine. My funds are now depleted, so it'll be a while until I can get a run of cassettes folded and try again.

I have asked Rob to reassemble to a 3/4 engine. I'll do the rest and refit it. Going to change the carb anyway. I was very tempted to assemble it myself, but my garage is a grit-pit, has no room in it, and wifey would probably have a fit if I did the job on the kitchen table.

My next engine, though, I hope to have a bash at myself when timescales are less limiting.

Righty-ho, I'm off to look at the "Bible" and price up a cam kit.

[jonclancy]

Hurrah!! Some good news to report.

I collected my engine from Rob yesterday. Luckily, it is a rebuild short block, with the head and sump to refit. A fully reassembled engine would have been hernia-worthy for both the Subaru and ME!

I need to degrease the outside before applying the Granville Satin-Black paint I have procured (hi-temp curing). I'm going for revised induction and exhaust manifolds. With the list of works completed, I'm sure you'll agree this is going to be one sweet 1275. I am now, officially, broke - but can't wait to get it fitted and back on the road for testing.

Car will be advertised once we know everything is A-OK, but take this as a preliminary announcement...

Invoiced engine works are:

Debung, clean and degrease block

Check and polish crank

Lighten flywheel

New ring gear

Balance bottom end

Hone bores to STD

Reface block

degrease/beadbalst block (supplementary)

Gas-flow head

Head - resurfaced for 10:1 CR

New Cam Bearings

New Piston rings

New oil pump

New Payen gaskets

New timing chain

Recut valve seats (three-angle)

Reface valves

Reassemble head

New valve springs, seals etc

AC Dodd RS camshaft



I'd be interested to see the power output, but this set-up should produce a torquey little lump. Hoping for around 80 bhp, but we'll have to see.

I'll be fitting the new brake drums and friction material front and rear, changing all fluids and checking the rear bushes when I get the engine refitted.