Richard Longman A-series, problem

[Pluscat]

My XI has a A-series engine, prepared by Richard Longman. Not just the cilinderhead, the whole engine. (engine and head have Longman numbers!)
Cilinder 4 has a low compression, (it is not the head, have tested that) and is blowing in the sump.
The engine needs to be bored and new pistons installed. Expensive but possible.

I'm affraid not. The engine (a 1275) should have a bore of approx 70 mm. My engine has a bore of approx 72 mm. So is this a 1380?
Boring it even farther isn't an option, I think, the limmits of boring a 1275/1380 A-series have been reached with this engine.

So what should I do? I tend to give the old blok wet liners (although I don't think they are very wet in an a-series) and new pistions. Anyone experience with a 1380 with wet liners (if that exists at all)?

[adamwilkinson]

Are you sure you've not got a broken ring on piston #4?

You can go bigger but you'll need to look at offsetting your bores.

[Pluscat]

I haven't taken the engine appart, except for removing the head. A broken piston ring is a possibility, (perhaps even a certainty), but the cilinderwalls have worn (about 0.04 mm), cilinder 4 most. A new pistonring would be a temporary fix, but it looks very much like the engine needs an overhaul.

[erictharg]

Any decent engine shop should be able to bore out the existing block and press in dry liners to reclaim cylinders. Failing that, you are looking for a new block! Fortunately not too rare yet. You can't run wet liners on an A Series (as far as I know) - taking out the whole cylinder wall would lose too much of the block strength.
But hopefully it is reclaimable.

[Pluscat]

You are right Charles! DRY liners not wet liners.
I hope to retain the engine in the car, for the historical point of view, cause that is how the car was made by Westfield.

But if a new block is needed: Would a 1275 from a Mini fit? I know the sump/gearbox on a mini is totaly different (Front wheel drive), but are there any differences on the block? In other words: Would a Mini block fit a MG-sump, enginemounts and gearbox?

[Pluscat]

The engine is out and largely dismanteled.
The block with crank and pistons is now at the workshop, and they suggested that it would be easiest to get a new block, and bore it to size, and use all the other bits from the old block (except for the barings ofcourse)

Now I have a problem: the bore is approx. 72 mm, are there oversized headgasket with that bore?

[jonclancy]

I thought 1380 and 1400 engines were 73.5mm and 74mm bores respectively.

This may help??

http://www.jonspeedracing.co.uk/index.p ... p&cID=2100

[xkfeng7]

What sometimes impresses me is the large range of rebuild prices you can find when looking for a 1380 (turn key or as a kit). At the top we have folks like APT that will build you a fast street motor 1380 for $12-$14k USD. In the middle you have folks like Minimania, MED, etc that advertise a turn key street/rally motor for $6kUSD, and then you have folks like Jonspeed and Skiptune who can do you a hot 1380 mill for less than half of MED's price. Yes, I realize that the cheap rebuilds leave out some operations that the expensive ones incorporate, but given that they all claim to make around 100HP and >90ftlbs of torque, it's amazing to see the 4:1 price differential. Is the effect for the end user primarily longevity?

[erictharg]

You pay for their expertise and hopefully the confidence that they will deliver what you want when they agreed to give you it.
My experience is that many people in the engine business are "me too" merchants copying someone they once worked for, or something they read once. And fail to deliver.
You usually get what you pay for. Supply and demand drive regional differences in price. And usually the less you know the more they will charge you - because they can.
They all claim to give the same product. But how many deliver? Those who have been around for a while are usually OK. But always look for recent feedback or references.
I use MED because they are an hour away from me. Worst case I can go and sit on their door step until I get what I ask for. They have been around a while and many other racers use their products with good results.
I would hate having to trust someone who was too far away for that! Unless I knew them personally.
Having said that the A series is still a simple engine, and putting one together carefully with known components and the aid of a good local engine shop / machinist should give you the same end result as one of the specialists.
My garage is not the cleanest environment, but the amount of care I take to keep an engine build clean is more than I've observed at many of the specialists!

[Westfield 129]

I have built a few of these engines, and it is possible that you have a broken ring. How that is fixed depends...

With your 72 mm bore 9 (might be 060 overbore), it may be possible to offset bore the engine to 73.5mm, which is the proper bore for a 1380. However, this bore must be "offset" as the space between the cylinders is enough to support a straight bore on the original centers. I usually start with engines bored from stock to .060 over, and with that bore, it is always possible to offset bore to the larger 73.5mm, and even 74mm for a full 1400 cc. Of course, if you do this, you will need a new set of pistons, probably at £300 a set, plus the machine work. Perhaps there is a special price on the AE squeeze cast pistons in 73.5 with a 7or 9cc dish.

If you can't do an overbore, then you can sleeve the cylinder, and re bore it. This is not an exotic bit of machine work, but I bet that it might be less expensive to acquire another block, machine it and transfer your parts, as suggested by your machine shop. In any case, don't throrow out that block!

Use a Payen gasket set, as their composite head gasket is the best, and will work with all bores available to the 1275 block, including the offset bores of 73.5 and 74mm.

Stuff happens even with the engines built by the best builders. Usually, there is no warranty.

As far as cost, well... I use all the same parts that APT uses (all the usual racing UK stuff), and purchase them from APT. My machine work comes from a highly regarded specialist, with extensive A series experience. The machine work costs about $1100 or so, which includes setting up the block with zero deck height, machining the deck, line boring, truing and polishing the crank journals. My cylinder heads usually come from Longman, and are of excellent quality, with good components. In the end, the cost of the parts, which often include a new Weber on a custom Maniflow intake, Swiftune or MiniSpares roller rockers, ARP studs and fasteners, custom exhaust header derived from a new Maniflow Mini Cooper header, Oil cooler, adapters and Pertronix ignition system, will run around $7000~8000 plus assembly labor. Sometimes, I get a deal, and can finish one for less, but usually, I am stuck with paying nearly $2000 for just the cylinder head, which is the most expensive single component. I do all my own assembly, and so far, with 4 engines in cars all producing around 125~130 HP (10.6:1~10.8:1 or more compression, SPVP3 scatter pattern cam), I have been lucky not to have one with a problem, including my own, with over 19000 miles on it. APT will do their own heads, and offer dyno time, which does increase the cost somewhat, as well as charging the usual rate local rates for assembly labor at about $100/hr.

If you use the same parts, and the same assembly techniques, you get the same engine, same power output. APT doesn't really keep secrets, so if you build a known combination as I did, they can even get you in the ballpark with the carburetor jets.

The key to a successful engine build? Superior machine work, and careful assembly. Make sure that you pick performance parts that are well known, and don't get creative. Build a known combination that works. Careful matching of the components will give you a good, powerful engine.