Joined: Sep 2017 Posts: 216 Threads: 29
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Greetings all, and HNY to you all.
May we have a cost run down please on rebuilding an engine without using a supercharger, to effectively give more power and torque.
This could be very useful for not just me but other newcomers.
My engine is totally unknown and I certainly don't want to start it up (I haven't even got a complete carb for it yet) and cause damage, so I prefer to strip it down entirely, which will happen in due course.
Could us newcomers be given some expert guidance, re what ought to be replaced as a matter of course, and the overall cost of doing so. The idea being not just a rebuilt engine, but one with additional power. It would appear therefore from Malcolm Parker's reply concerning a blown engine that 30 plus BHP can be obtained without a blower being fitted.
Some guidance and costings will be much appreciated. Malcolm mentioned a "Barlow" crank, I don't know of this, I know of Phoenix of course, plus what pistons have been used.
Maybe this kind of guidance could be offered as a standard "document" for newcomers.
To recap then, what is the maximum road usable power that could be obtained, combined with reasonable economy, and at what cost?
regards
Arthur
Joined: Mar 2015 Posts: 5,188 Threads: 223
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A good place to start would be some reading Arthur.
Try:
Austin Seven Specials by Bill Williams
also,
Design for Competition and Austin Seven Companion both by 750MC
These detail modifications that many had used over the years and will assist in planning the route you want to take.
Hadley, Allen, Barlow, Pheonix (and others) have all produced cranks (splash, pressure, 1 5/16” and 1 1/2” counterbalanced etc. options) and Zeto appears to be producing some as well now.
Decide what your end goal is and then come back with questions.
Every build is different and one document would not be sufficient.
Joined: Aug 2017 Posts: 106 Threads: 3
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I supplied a 2 bearing seized engine to Pigsty for rebuild.
Phoenix crank, Sainz rods, etc and built to their road/race spec.
Cost 2 years ago about £4800 including running in and dyno test.
Max POWER 30.2 hp @ 5406 RPM
Max TORQUE 37.7 lbft @ 3412 RPM
I'm sure it'll be quite enough power without a supercharger for when I finally get the car on the road,
Joined: Mar 2015 Posts: 5,188 Threads: 223
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I have a copy of the latest Practical Classics A7 publication but have yet to read it.
Some have commented that it has a good overview of what to look for in rebuilding - it was £6 from memory.
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Yes, Bill Williams. Plus I'd ask any 'newcomer' what do you want more power for? In my opinion reliability is much more useful...
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(02-01-2018, 03:38 PM)Ruairidh Dunford Wrote: I have a copy of the latest Practical Classics A7 publication but have yet to read it.
Some have commented that it has a good overview of what to look for in rebuilding - it was £6 from memory. Good to familiarise anyone with a seven who hasn't dismantled an engine before.If you read Bill William's book do read all the corrections (in the later copies) at the back as there were a lot of errors.
Also 750 companion for tuning
Joined: Aug 2017 Posts: 856 Threads: 16
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Location: North Yorkshire
It is essential to use a good crankshaft if you are building an A7 engine. For road use and modest competition, I would stick to a splash fed 1 5/16" crank (others might disagree!)
A set of good standard Austin con rods will be okay for general use but you will need to keep the revs down to about 5000. The white metal bearings need to be done properly. A set of special forged con rods will set you back about the same as a new crank but will allow higher revs and greater peace of mind.
Good racing type pistons are readily available from the specialist A7 suppliers.
I think the budget of £5K is realistic for a moderately tuned unblown engine.
It isn't all about power, for a road car you want plenty of low down torque. I favour standard size valves, modest fettling of the ports, a trials spec cam and an SU carb on a long inlet manifold. I am sure others will disagree!
Gearing is more important than engine power. For a road car a 5.25:1 axle ratio (the easiest to obtain) and 19" wheels works well. Money spent on a close ratio gearbox is money well spent.
If you are building a special, keep the weight down. Some of the sexy looking single seaters are quite heavy. A simple Ulster body is readily available and can be very light.
As this thread is about costs, I should point out that I am a Yorkshireman with some Scottish blood! I did my own upholstery for about £150 and brush painted the car for less than £100. This reduced the pain of building a decent engine!
Joined: Aug 2017 Posts: 1,808 Threads: 99
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hi arthur,
a reasonable question, how much.
but you are going to get alot of different answers.
first off, are you looking to save by doing the work yourself. or looking for someone else to build.
if not as suggested pigsty at £4,800 a couple of years ago. this price sounds very sensible, as you get the time on the dyno.
if you are looking to do the work yourself, then you are looking for prices of parts only.
there are several suppliers of parts out there, different suppliers may sorce there parts from different places. i find its very handy to attend the main jumbles and see the difference in price to quality of whats on offer, so you can make your own mind up on what parts you are fitting.
as im a trader myself, i hope my statement is fear to all.
i would also check everyones websites, or ask aditional questions on the phone for whats available.
for instance, ive just started to restock reconditioned blocks. after not doing them for around 8 years. price at the momment is £800.00 this includes £300 of labour and machine work from the company we use and parts came to £504.00 ive not added anything on for the running around as yet. or the bit of fitting ive had to do myself. so expect prices to rise. these will go onto my website soon.
as suggested there are a number of different crank manufacturers about, personally i like to supply pheonix, theve had a good reputation for decades. i beleive next years list price for 1 5/16 splash is £650 plus vat. but again. different suppliers will have different prices, on availability.
dont forget to factor in things like cleaning, if you are paying for thing like soda blasting.
if you want to know more about getting extra power, as R suggests buy the bill williams book. but this will give you the cheats as well as how to do it properly. so pick the way you want to go.
tony
Joined: Aug 2017 Posts: 113 Threads: 6
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Tony,
What does your "reconditioned" block include?
I had a block from quarry when I rebuilt the saloon about 8 years ago which was bored, faces skimmed, new pistons, new bigger valves, new valve springs, new guides, new tappets.
I am looking for a similar service for the new engine for my cup model.
Thanks
Peter
Joined: Sep 2017 Posts: 216 Threads: 29
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Some good advice, many thanks chaps.
I've got all the books mentioned and have a copy of the Practical Classics mag, in fact took it to the hospital this afternoon whilst the wife was having her eyes done!
I want to compare the costs of a "standard" rebuild...if such a beast exists, and a rebuild for more power/reliability/tractability in modern road conditions etc.
The chap in the magazine, Ian Bancroft, is he still rebuilding engines I wonder? I noticed in his rebuild that he didn't automatically renew the crank...clearly he tested it for cracks, but I've read on other posts that some would automatically renew a crank for example, and IB in the article displayed cracked con rods and had to replace 2 of them.
I guess it is all about budget, which clearly can run away.
Early days yet, as the chassis is dismantled and I'm about to rebuild it all over the next couple of months.
I must admit, new crank/rods/pistons seems a very good idea as a starter.
Now, you might laugh at this, but I've read variously that rebuilds are required around the 30K mark? How, realistically, can this all be extended, for example, the new crank/rods/pistons and perhaps a lot more, might the rebuild time be extended?
I'm assuming that going to a full rebuild might see me through a decade, and I would expect to knock up more than 30K miles during this period perhaps?
Arthur
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