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Jun 16, 2014 10:41 am
Jun 16, 2014 10:41 am
Subject: Re: 4.5 litre engine problems and upgrades
Dear David,
Sorry to hear of your problems with the liners. javascript:InsertTagsMenu('%20:\'(%20',%20'',%20'bbsmileys') We have similar problems and have just wrecked another number 6 piston in exactly the same way as you describe. Our car is AXD 45 an M45.
We replaced the block about 30,000 miles ago and unknown to us a circlip holding the Gudgeon pin failed. The end of the pin slowly ground a groove in the side of the bore and the crankcase fumes got worse and worse.
Being a relatively new block we decided to sleeve each bore. This worked fine for about a year, but we did not do a lot of motorway miles or rally miles. Soon after (about a month) replacing normal coolant with Evans waterless coolant and going up this particular hill there was a loss of power and woft of fumes. Water temp 80 degrees.javascript:InsertTagsMenu('%20:\'(%20',%20'',%20'bbsmileys')
We stripped down the engine, found that the No6 had ground itself into the sleeve. Luckily we could hone the sleeve back to an acceptable condition. The water pump bearings had gone and simply thought that this was the problem.
We took the opportunity to put new water pipes into the block at the front and rear of the engine even though we had previously got an extra pipe installed to the back of the head like you.
We run the transfer ports so that the front one is blanked off, the middle one half blanked and the rear one fully open. This effectively forces the coolant from the front of the block to the rear and up to the head and then back to the front of the engine.
Anyway we got the car going about two months ago, run her slowly for 500 miles, but on the way to Goodwood on June 1st on the same hill at 2000 revs, 65mph, 80 degrees c exactly the same thing happened.
So car is now in bits and having entered the 1000 mile trial next month we are somewhat under pressure to have it running at full capability by then. It seems that the piston that we put in just did not have the tolerance even though we had a new water pump and improved circulation with delivery direct to No6. I can see that the heat is not dissipated as fast with liners, and therefore a smaller piston is required. We had no signs of overheating at any stage.
I am also concerned that if I had been using a traditional coolant there would have been boiling around this cylinder, the temperature would have suddenly increased and I would have been able to reduce the power. I am not convinced by the waterless coolant and we have never had localised cooling issues before introducing this.
I think that localised boiling might agitate the water based coolant and remove heat faster from the outer edges of the sleeves, not slower as the bumpf says on the packet.
Hopefully we can get the new piston machined in the next couple of days and get back into action with more tolerance. We have decided not to use waterless coolant for the time being as these engines have always worked well on traditional coolants.
I will report back, as on the first day of the rally we are doing driving tests flat out on the top gear test track and the Prescott hill climb. If it can do that then I think we will have got around the problem! Fingers crossed.
I can see that getting a new block is the ideal solution, but it is somewhat pricey and cannot be done this week!
James Mann 07803716815
Dear David,
Sorry to hear of your problems with the liners. javascript:InsertTagsMenu('%20:\'(%20',%20'',%20'bbsmileys') We have similar problems and have just wrecked another number 6 piston in exactly the same way as you describe. Our car is AXD 45 an M45.
We replaced the block about 30,000 miles ago and unknown to us a circlip holding the Gudgeon pin failed. The end of the pin slowly ground a groove in the side of the bore and the crankcase fumes got worse and worse.
Being a relatively new block we decided to sleeve each bore. This worked fine for about a year, but we did not do a lot of motorway miles or rally miles. Soon after (about a month) replacing normal coolant with Evans waterless coolant and going up this particular hill there was a loss of power and woft of fumes. Water temp 80 degrees.javascript:InsertTagsMenu('%20:\'(%20',%20'',%20'bbsmileys')
We stripped down the engine, found that the No6 had ground itself into the sleeve. Luckily we could hone the sleeve back to an acceptable condition. The water pump bearings had gone and simply thought that this was the problem.
We took the opportunity to put new water pipes into the block at the front and rear of the engine even though we had previously got an extra pipe installed to the back of the head like you.
We run the transfer ports so that the front one is blanked off, the middle one half blanked and the rear one fully open. This effectively forces the coolant from the front of the block to the rear and up to the head and then back to the front of the engine.
Anyway we got the car going about two months ago, run her slowly for 500 miles, but on the way to Goodwood on June 1st on the same hill at 2000 revs, 65mph, 80 degrees c exactly the same thing happened.
So car is now in bits and having entered the 1000 mile trial next month we are somewhat under pressure to have it running at full capability by then. It seems that the piston that we put in just did not have the tolerance even though we had a new water pump and improved circulation with delivery direct to No6. I can see that the heat is not dissipated as fast with liners, and therefore a smaller piston is required. We had no signs of overheating at any stage.
I am also concerned that if I had been using a traditional coolant there would have been boiling around this cylinder, the temperature would have suddenly increased and I would have been able to reduce the power. I am not convinced by the waterless coolant and we have never had localised cooling issues before introducing this.
I think that localised boiling might agitate the water based coolant and remove heat faster from the outer edges of the sleeves, not slower as the bumpf says on the packet.
Hopefully we can get the new piston machined in the next couple of days and get back into action with more tolerance. We have decided not to use waterless coolant for the time being as these engines have always worked well on traditional coolants.
I will report back, as on the first day of the rally we are doing driving tests flat out on the top gear test track and the Prescott hill climb. If it can do that then I think we will have got around the problem! Fingers crossed.
I can see that getting a new block is the ideal solution, but it is somewhat pricey and cannot be done this week!
James Mann 07803716815