Haffie Engine Issues

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Garrycol
Australia
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Location: Canberra Australia

Re: Haffie Engine Issues

Post by Garrycol »

Thanks for all those comments - I guess I will find out shortly when I take the head off.

Garry
1973 Haflinger AP700
1977 Landrover FC 101
2007 Range Rover Sport TDV6
1971 Jaguar Series 3 E-Type Conv
1957 Landrover 88" Station Wagon
1957 Landrover 88"
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Garrycol
Australia
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Location: Canberra Australia

Re: Haffie Engine Issues

Post by Garrycol »

After a bit of mucking around I managed to get the piston out.

There seems to be a few things going.

1. There is light erosion on the exhaust side of the piston top most likely the result of pre-ignition at some time.

2. It looks as if the valves have impacted the top of the piston bit seems not to have damaged the valves but there are some intents on the top of the piston. No evidence on the exhaust valve but there is a bright impact spot inlet valve - indents obvious on the piston. This may have actually occurred previous with the tappets turned up tight that were not allowing the valves to close. Unfortunately I don't know what piston was like at the start - looks like a flat dome with indents for both valves.

Image

Inlet side
Image

Exhaust side
Image

The valves - see the bright spot on the inlet valve that batches the damage on the top of the piston. Nothing on the exhaust valve (covered up by carbon is my guess) which makes me think this is from when the tappets were too tight.
Image

3. The cause of my current issue - is looks like the extended piston skirt on the inlet side has somehow impacted with the conrod near the bigend and broken and cracked the lower half of the piston.
Image

Where it probably impacted the conrod - you can just see a mark on the conrod in the centre of the pic.
Image

The bore is undamaged though right at the top there is some erosion similar to the the top of the piston most likely cause by pre ignition. Is perfectly serviceable.

What does have me confused is why there is no compression on this cylinder even with the damage to the piston the top of the piston is basically intact and even if the rings are damaged (which they do not appear to be) there should be at least some compression.

The oil is all good, no metal at all, the broken chunky bits from the piston have been recovered and did not go through anything and there are no small bits in the engine. I will wash out the bottom end with some like oil to ensure anything that might still be there is removed. I have not pulled the second piston - while there is nothing wrong with its operation and it has full compression I guess I need to pull it to check whether the valves have kissed the piston and do whatever is required to ensure what happened to No1 piston does not happen to it.

The oil is all good, no metal at all, the broken chunky bits from the piston have been recovered and did not go through anything and there are no small bits in the engine. I will wash out the bottom end with some like oil to ensure anything that might still be there is removed. I have not pulled the second piston - while there is nothing wrong with its operation and it has full compression I guess I need to pull it to check whether the valves have kissed the piston and do whatever is required to ensure what happened to No1 piston does not happen to it.

My guess is that whoever built this engine has made some tolerances too close. Valves to piston and piston skirt to conrod. The big end of the conrod looks as if it has been ground down (the shiny bit in the pic above) to give clearance to the piston skirt. I cannot work out what pistons are actually in it - all 87mm VW pistons I have searched have all been flattops so tomorrow I will go to a VW specialist to discuss. I will also take the barrel to my engine guy for a rehone but if it needs more that will mean the other barrel will also have to go in. I will also discuss if I am able to take a bit off the piston skirts to give a bit more clearance.

So there it is.

Garry
1973 Haflinger AP700
1977 Landrover FC 101
2007 Range Rover Sport TDV6
1971 Jaguar Series 3 E-Type Conv
1957 Landrover 88" Station Wagon
1957 Landrover 88"
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edzz
United States of America
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Re: Haffie Engine Issues

Post by edzz »

I am at a loss as to the cause however I suspect he polishing on the big end of the rod would have been to provide clearance between the rod and cylinder base not piston.

The only part of the rod that could contact the piston skirt would be near the small end of the connecting rod and that would be highly unlikely if the big end of the rod is intact.

The only time I’v had piston skirt damage like that was when I had a bolt let go on the big end of the connecting rod of a Triumph Tiger I had years ago, however I am not seeing the related damage near the crankshaft to support that idea.
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
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Jimm391730
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Re: Haffie Engine Issues

Post by Jimm391730 »

One possible scenario is that the valve springs are tired, allowing the valves to close more slowly (especially at high rpms, as you described in your first post). So the piston gets up to TDC faster than the valves can close, and the piston hits the valves. You should check for broken valve springs, and/or proper spring pressure. I also suspect that one or both of the valves are bent ever so slightly, and won't seal well, giving the low compression readings.

High rpms also put strain on the piston skirt, which can shatter from the stress of being "stretched" as the piston is pushed upwards faster than the strength of the cast aluminum can take.

What I do not know is what the max rated rpm of the engine really is. Obviously, if the springs, pistons, etc. are really 50 year old parts they are likely to be somewhat tired.
Jim M.
712W and 710M
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Garrycol
Australia
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Re: Haffie Engine Issues

Post by Garrycol »

Thanks for those responses - Edzz you are of course correct the shirt will always be to far from the big end to hit - may have been a fragment coming away.

Jim - I had some work done a little while back where it was found the valves were not closing due to the tappets were adjusted too tight so there was always a chance of valve to piston collision. Certainly when the work was done the engine worked very well (maybe too well :( ). I agree time to have a look at the heads, valves and springs - the pushrods and rockers are all OK.

The engine was built a couple of years ago where the barrels were replaced with 87mm Mahle VW aftermarket barrels and 87mm pistons - the clean condition of the combustion chambers and the state of the bores show this recent build. What I don't know what was done to the heads re different valves and springs etc I need to find this out. I have bits from an old engine and will check its head to compare valve sizes. I think it will be just safer to get the head rebuilt - maybe do the spare heads and put them on.

According to the handbook the governor starts restricting power between 4800 and 5200 rpm so the red line would be in that area. At the time of failure engine, engine revs was less than that but was going up an incline so under a bit of load but higher revs.

Cheers

Garry
1973 Haflinger AP700
1977 Landrover FC 101
2007 Range Rover Sport TDV6
1971 Jaguar Series 3 E-Type Conv
1957 Landrover 88" Station Wagon
1957 Landrover 88"
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Garrycol
Australia
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Joined: Sat Oct 06, 2012 6:49 am
Location: Canberra Australia

Re: Haffie Engine Issues

Post by Garrycol »

As I am mid way rebuilding a Rover 4.6 V8 I have an on going dealings with a local engine builder. He said that the engine has been running for a time with advanced timing - new that fixed previously and that while there may have been inlet valve impact this time around it looks like it has been happening for a little while - the exhaust has previously impacted but with its current carbon build up it hasn't happened recently - this would tie in with previous tight tappets and it now being OK.

He said the the cylinder has been over heated as it shows it in the bore and on the sides of the piston. There is evidence of seizing on the piston and bore when the piston was at TDC. He suspects the piston seized in one area and the piston at the bottom slammed into the side of the bore either breaking it then or causing a crack which subsequently broke the bottom of the piston.

He also spotted that the head is also cracked where it fits over the barrel and is warped. The barrel and piston is Mahle but no one has ever seen a piston like mine as most are flat tops. So if you recognise this 87mm Mahle piston please let me know.

Image

I have two spare old heads so I will get these refurbished though getting sodium filled valves will be an issue here.

PS - I have just pulled the head and barrel on No2 cylinder and it is as new - no issues - nothing at all. Where force had to be used to do No 1 cylinder, No 2 just came straight off no issues. So this would also point to earlier issues with No1 that all came to together the other day resulting in failure if this was not the case No2 cylinder should also have had some problems.

Cheers

Garry
1973 Haflinger AP700
1977 Landrover FC 101
2007 Range Rover Sport TDV6
1971 Jaguar Series 3 E-Type Conv
1957 Landrover 88" Station Wagon
1957 Landrover 88"
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TechMOGogy
Canada
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Re: Haffie Engine Issues

Post by TechMOGogy »

Shame about cracked and warped head!
Glad you have some spares!
Talk to Robert or Leo about new valves
72 Pathfinder | 75 710M 2.7i | 96 350GDT Worker
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Garrycol
Australia
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Location: Canberra Australia

Re: Haffie Engine Issues

Post by Garrycol »

I have sent a message to Leo who has in the past provided me good advice on my carby - my main issue is that I have spent about 10 hours searching on the web for the Mahle piston I have and have not found it.

If I cannot find it, it will have to be different pistons and associated barrels but I am not sure what ones I should get.

Cheers

Garry
1973 Haflinger AP700
1977 Landrover FC 101
2007 Range Rover Sport TDV6
1971 Jaguar Series 3 E-Type Conv
1957 Landrover 88" Station Wagon
1957 Landrover 88"
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westernair
United States of America
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Location: Tacoma, WA

Re: Haffie Engine Issues

Post by westernair »

talk to scott at EI and see if he still has a set of Nikkies on the shelf.
Amazing pistons and barrels for a Haflinger.
Shawn

62 haffy Bantam
61 haffy 4 door

72 710K - Sold
73 712M - Sold
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Garrycol
Australia
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Re: Haffie Engine Issues

Post by Garrycol »

CAUTION - VERY LONG POST

I have been spending a bit of time with my engine builder and doing some "forensic" analysis of the damage and why it has happened. The undamaged No2 cylinder shows that the mods done to the engine were sound. These were, the installation of a 87mm big bore VW kit for the aircraft version of the VW beetle engine (standard Haffy is 80mm bore). The evidence now shows the piston top was turned down to provide the raised section in the centre of the piston and the insets for the valve were milled in. This provides increased compression ratio and raised the capacity of the engine to 762cc. The exhaust valve is standard but the inlet valve is increased to 40mm. The only down side of the modification is that the inside rim of the head has been taken out to fit the top of the 87mm barrel and this takes a bit too much metal out where the pushrod tubes are as that is where the head is thinnest.

In my engine's case No2 cylinder has worked well but not so with No1. Firstly it seems that when machining the barrel to fit the piston stroke they took a thousandth of an inch too much off and the top of the piston has been touching the bottom of the head - in the pics of the head and top of the piston you can see the erosion around the edge of the piston and head next to the exhaust. Also it would seem the head did not go on straight as it was only this side that was touching. It would also seem at this very early time after the build, and because of the tight tolerance the valves have also touched the piston. As you can see in the pic above there are dents in the piston but the valves are not bent (checked today). This indicates the valve and the piston were going in the same direction (ie valve closing and piston going up) and the valve just got a hurry up from the piston and from then on the extra dents in the piston top have provided the clearance needed for the valves.

Since I have owned the Haffie compression on this cylinder has always been a bit down and this was subsequently shown to be because the tappets were tight and inspection today showed that while the exhaust valve is OK the seat was a bit burnt not allowing the valve to close correctly. This is most because of the highly advanced ignition found six weeks ago - not sure why No2 exhaust didn't suffer the same. So it would seem that No1 cylinder did not have the tolerances required but while the engine was under performing it held together.

6 weeks ago the tuning of the engine is set up, the ignition set right to develop max power and the tappets set correctly - power is now much greater and what is was designed for - No2 cylinder responded but it was built with the right tolerances. No1 cylinder was now also developing more power with its associated heat. However it does not spare capacity and as the piston is still touching the head and other bits are not working to full capacity the cylinder overheats at the very top and the piston seizes on the the exhaust side at TDC where is also touches the head. There is a slight turning moment in the piston as it is momentarily stuck to the bore next to the exhaust and this cracks off the piston skirt extension on the opposite side of the piston and causes the piston to crack - the piston is 86.5mm in diameter and the bore is 87mm so there is .5mm gap which is huge at the speeds the piston goes - there is a graze mark on the bore.

Without actually being inside the engine when this happened it is difficult to know what exactly happened but the above does seem to fit with the damage.

WHERE TO FROM HERE

The bottom end is all OK. No 2 Cylinder is all OK.

No2 Piston
Image
Any work done on No1 cylinder will have to be done on No2 so that equilibrium exists in the engine.

We are getting a new 87mm big bore kit and the pistons will be turned down to replicate the current pistons. To get around the issues of taking too much metal out of the heads to fit the barrels, the tops of the barrels will be turned down - they are strong enough but fit inside the head any way so are reinforced by the head. The barrels will be made 1/1000 inch longer than is needed to ensure the pistons do not touch the heads. New heads are needed as my old ones where skimmed to take the barrels and I have these from an old engine carcass in my spares. The older haffie heads are a slightly different casting that the later ones. The new valve seats for the 40mm valve have already been cut. As the piston/barrel kits only come in 4 piston lots I will get the the spare two pistons and barrels also modified so I have spares in the future.

The lot will be dry fitted and blued to ensure clearances are there but we should put the engine together properly and all blued and run it to operating temp and then pull it down but that will be difficult. As long as we build to current No2 specs and add 1/1000th inch to the length of the barrels all should be OK.

So there it is - not as expensive as it sounds, though I don't have the bill yet - the extra cost is in having to buy four piston/barrel sets rather than just two.

Garry
1973 Haflinger AP700
1977 Landrover FC 101
2007 Range Rover Sport TDV6
1971 Jaguar Series 3 E-Type Conv
1957 Landrover 88" Station Wagon
1957 Landrover 88"
Tennmogger
Posts: 1
Joined: Fri Oct 04, 2013 3:53 pm

Re: Haffie Engine Issues

Post by Tennmogger »

Wow. Fascinating! Thanks

I sure would like to experience the ride after your project is done.

Bob
Heinkeljb
Great Britain
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Location: Lewes,Southern England

Re: Haffie Engine Issues

Post by Heinkeljb »

You could get your old heads Ali welded to repair the cracks and put back missing metal. Expensive task probably, but if you can't get hold of cylinder heads then maybe an option.

If the head wasn't damaged, could you have put a thicker head gasket on to gain the extra thou' of an inch?

I hate putting broken bits back in storage, but know that you have to as there may come a time when you need that particular part. Only trouble is, you remember you have that item in your spares, then when you need it and find it. You realise that it needs work to make it usable again! I have a couple of barrels for my Heinkel like that! I think they need re-bores at least, but might nee the odd bit of fin welded...

Keep the pictures coming, particularly of the Blue printing of the engine if you can persuade your engine guy to take photos!

John
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