My vintage engine rebuild

[crankedup]

My little Austin seven engine has been blowing blue oil smoke for ages now and gets worse on every trip out, so I am having the engine rebuilt end of next month. The Company I have selected to do the work have an excellent reputation for quality work and fair prices. My question is when they have stripped the engine should I say replace all the bearings/valves/pistons in fact just about everything as in belt and braces or go with what they suggest needs to be done? I expect rebore is definitely needed but I don't want to throw money at it like its going out of fashion, at same time my Austin is a long term keeper.

[Steve_D]

crankedup said:

My little Austin seven engine has been blowing blue oil smoke for ages now and gets worse on every trip out, so I am having the engine rebuilt end of next month. The Company I have selected to do the work have an excellent reputation for quality work and fair prices. My question is when they have stripped the engine should I say replace all the bearings/valves/pistons in fact just about everything as in belt and braces or go with what they suggest needs to be done? I expect rebore is definitely needed but I don't want to throw money at it like its going out of fashion, at same time my Austin is a long term keeper.

If you believe they are good then leave them to make the decision.
A rebore now is one less the engine has in it's life so they should consider that carefully. Bearings will get replaced or re-metalled. Valves will get replaced only if they are worn. Pistons will only be replaced if a rebore is required or if they are damaged. They will get new rings and as a minimum they will hone the bores.

Hope it goes well. My brother has a Seven.

Steve

[crankedup]

Steve_D said:

crankedup said:

My little Austin seven engine has been blowing blue oil smoke for ages now and gets worse on every trip out, so I am having the engine rebuilt end of next month. The Company I have selected to do the work have an excellent reputation for quality work and fair prices. My question is when they have stripped the engine should I say replace all the bearings/valves/pistons in fact just about everything as in belt and braces or go with what they suggest needs to be done? I expect rebore is definitely needed but I don't want to throw money at it like its going out of fashion, at same time my Austin is a long term keeper.

If you believe they are good then leave them to make the decision.
A rebore now is one less the engine has in it's life so they should consider that carefully. Bearings will get replaced or re-metalled. Valves will get replaced only if they are worn. Pistons will only be replaced if a rebore is required or if they are damaged. They will get new rings and as a minimum they will hone the bores.

Hope it goes well. My brother has a Seven.

Steve

Thanks Steve, guess I knew the answer really, just a bit nervous as this is first time any of my engines will have been rebuilt in my ownership. But if the engine has been rebored to its maximum, and I guess it has because its the orignal to the car, will they sleeve it?

[Steve_D]

crankedup said:

But if the engine has been rebored to its maximum, and I guess it has because its the original to the car, will they sleeve it?

Not sure if you can.
Been a long time since I worked on a seven engine.

Steve

[Pumaracing]

Your build starts not by trying to decide what you might want to do but from detailed measurement of what you actually have. A comprehensive evaluation of the engine's current state would include inter alia.

1) Bore wear at top, middle and bottom measured in thrust plane and also at 90 degrees to that.
2) Piston skirt diameter vs new
3) Piston ring clearance in grooves preferably checked against new rings.
4) Wear in piston gudgeon pin bore
5) Gudgeon pin wear or scoring
6) Crankshaft journal measurements in two planes on all main and big end journals.
7) Camshaft lobe check for equality of lift on all lobes and wear patterns.
8) Visual examination of cam followers for pitting, scuffing or concavity.
9) Valve stem wear
10) Valve guide wear
11) Strip and check oil pump internal tolerances.

Things which would be done without any further thought would be replacement of all bearings and recutting of valve seats, refacing of gasket surfaces.

If you want a second opinion on any measurements post them here and I'll look them over.

Dave Baker
Puma Race Engines

[crankedup]

Many thanks as always Dave for an authoritive/informative post. The Company who will be working on my little engine is the very well respected Scholar Engines Ltd, I'm sure you know of them as they carry out the majority of thier work on race engines. My engine go'es to them at end of Sept' / mid October and I shall post up how things go, purely as a matter of interest and not judgement.

[Pumaracing]

I'm sure Scholar will know what they're doing. You might be able to get the bits cheaper though. I suggest you ask for a strip down report with measurements and costings first then see what you can get the bits for online or from a 7 specialist. At the very least you can use it to negotiate a discount on full retail from them.

[Pumaracing]

I'd also suggest you do a compression test before you decide you need a full rebuild and certainly do another one once it's run in immediately after the rebuild so you can see how things have improved. I recommend all my customers to do regular compression tests and note them down in a log book to track their engine's condition after each race or rebuild or X thousand miles. It's invaluable to be able to refer back to a previous test and spot a developing problem before it turns a drama into a crisis. Trouble is no one ever does cos it's hassle and then when the engine starts playing up and they do do one there's no baseline figure to evaluate it against and see how much worse things have got, if at all. Even if they do them they don't log them down and then subsequently forget them again. You can lead a horse to water.....

[crankedup]

Thanks again Dave. I have done a compression test and all cylinders were 8.1 - 8.5 which was just inside accepatible parameters or a bit low by some standards. This was about 6 months/ 500 miles ago. Whatever the oil is certainly getting up on top of the pistons and rapidly getting worse. But I have taken on board your suggetions and have a couple of A7 specialist parts suppliers lists and prices ready.

[ettore]

Have you considered using an Austin Seven specialist? Scholar obviously have a good reputation and I would certainly head there for a FF1600 rebuild but there are lots of little Seven-specific tweaks learnt over many years of hard won knowledge (and broken crankshafts!)

..in fact speaking of the latter, a phoenix crankshaft is to be recommended for reliable valve bouncing...!

[crankedup]

ettore said:

Have you considered using an Austin Seven specialist? Scholar obviously have a good reputation and I would certainly head there for a FF1600 rebuild but there are lots of little Seven-specific tweaks learnt over many years of hard won knowledge (and broken crankshafts!)

..in fact speaking of the latter, a phoenix crankshaft is to be recommended for reliable valve bouncing...!

I have had a think on regards a 7 specialist to do the rebuild for me, however, a couple of guys have had their 7s rebuilt by Scholar and are very pleased with results. Add to that Scholar are within shouting distance of my house and the reasonable quote and its a no brainer in the end.The last time I used an 7 specialist I found the work to be very very expensive which kinda surprised me.

[ettore]

crankedup said:

ettore said:

Have you considered using an Austin Seven specialist? Scholar obviously have a good reputation and I would certainly head there for a FF1600 rebuild but there are lots of little Seven-specific tweaks learnt over many years of hard won knowledge (and broken crankshafts!)

..in fact speaking of the latter, a phoenix crankshaft is to be recommended for reliable valve bouncing...!

I have had a think on regards a 7 specialist to do the rebuild for me, however, a couple of guys have had their 7s rebuilt by Scholar and are very pleased with results. Add to that Scholar are within shouting distance of my house and the reasonable quote and its a no brainer in the end.The last time I used an 7 specialist I found the work to be very very expensive which kinda surprised me.

Fair enough. If the budget stretches I would recommend a phoenix crank tho'.