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evening all, been doing a lot of thinking and come up with a bit of a plan to tackle the mg and keep it going over winter. too cold for painting and prep at the moment so i'm going to do some mechanicals so they are ready to drop in....... i had thought about an engine swap, but i love the sound of a bseries and the character of a period tuned lump of pig iron, and i'm working on a budget of S.F.A - providing my lump is not scrap it will be staying. i turns over freely by hand, I'm going to whip the head off at the weekend and have a look at the bores. other than this, what are the best ways to check it before a new gasket set and a lick of paint? Once thats done it will obviously need mondifying a bit, so other than port matching to the manifolds, vizard style carb mods, quality filters/stub stacks and my stainless exhaust, am I missing anything else I can do to give it a bit more oomph, bearing in mind this needs to be done cheap! And lastly, i want to check the box too, whats best to use to clean the gearbox out and get rid of any sludge, thin oil? or something specific? both the engine and gear box have been sat for quite a few years. Cheers in advance! Have some p-b randomsss
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wanted, 25th hour. Required daily, cash waiting
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Engine checks - if you want to strip it right down, check the crank bearings for scoring and wear (shows up as copper colour on white metal bearing), the piston-bore gaps (or just check to make sure that there is no lip at the top of the bore), and the valves for play in the guides (remove the springs, open the valve about 1/4" - if you can just feel the valve rock when you try to move it sideways, it's marginal).
If you find wear, then you could either live with it (bearing in mmind you'll end up with less power, more oil and fuel consumption and more noise), find a better engine (always a gamble), refresh it (new shells and rings, valve regrind), rebuild it (rebore, new pistons, rings, crank regrind w/ new shells, valve guide replacement, valve seat re-cut and valve replacement) or get a recon exchange engine.
If you find corrosion on the bores, then you mgiht get away with honing the bores and fitting a new set of rings - although if the corrosion is deep then you might have to re-bore it.
Assuming that the engine is largely sound (and as a B series, unless it's done silly miles or has been neglected, it should be fine - they are tough as old boots), tuning is largely a mater of getting more air fuel mix in, burnt mroe efficiently, and out. So: -Regrind the valves to make sure they seal. -Open out the port throats, just behind the valves, so that the valve seat blends smoothly into the port, without a significant restriction in diameter. -Clean up the ports - remove nasty casting marks etc. Don't polish the inlets - you'll get a loss of low-end torque. -Free flowing exhaust (although AFAIK, the standard B one isn't bad). -Up the compression ratio with a head or block skim, but be careful not to go too far. -Better air filters -Suitable carb needles -Uprated ignition (good plugs - Denso seem best at the moment - Lucas Sport coil, electronic ignition of some description, good leads, cap and rotor arm).
After that you need to start looking at replacement camshafts, bigger valves and other such expensiveness.
As for the gearbox, someone on the SD1 forum flushed his out with thinned down gear oil - IIRC, he used a mix of gear oil and paraffin, starting with a mix of about 20% gear oil and working through increasing concentrations about 4 flushes to 100% gear oil before finally refilling with neat gear oil. He had the engine running, and worked through the gears with the wheels off the ground to make sure that the flushing oil got into every part of the box.
However, I can't vouch for that method personally.
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cheers j-rev, thats pretty helpfull. As far as i know the motor has done about 80k but i have no way of verifying this, however my old mans B has done about 130 on the original engine, think the bottom end is untouched but it had an unleaded head a couple of years back.
googling last night found me a couple of local engine builders that do historic race cars etc, so I can get some quotes if it needs a re bore and crank grind, thats the point where I start considdering donors and conversions!
Any one else with thoughts on the gear box?
Cheers
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wanted, 25th hour. Required daily, cash waiting
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DutyFreeSaviour
Europe
Back For More heartbreak and disappointment.....
Posts: 2,944
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I'd double check the chain tensioner too - had mine go on me and totalled the engine...... get the crank pulley off and timing chain cover to check (it leaks - o it'll need to come off for a new gasket anyway ) Also - rear of engine (depending on age) 'could' have the old rope type seal - which will have dried out and will disintegrate on use again. Get the rear crank seal checked and replaced while you have it apart - cheap part but a lot of work if ti goes while in the car and will ruin the clutch as it leaks oil everywhere...... (did that too ) Gearbox - you'll be dropping it out - clutch will need doing probably if standing so long.... IIRC - MGB box has side inspection plate - so tip it over and get the paraffin and clean it out and check for wear etc... should be enough - they are tough old beasts.
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Back from the dead..... kind of
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yep, they are both out and separated already so ready to work on.
Timing cover gasket/seal were on my list, and crank seal is on the list too - tensioner now added!
how is best to preserve them once i've doen this before fitting? bit of oil in the bores and leave it at that? They are stored in a dry garage
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wanted, 25th hour. Required daily, cash waiting
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Nathan
Club Retro Rides Member
Posts: 5,649
Club RR Member Number: 1
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If you have the timing cover off you may as well dump a Vernier timing gear on the puppy
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would this have much benfit on a standard cam?
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wanted, 25th hour. Required daily, cash waiting
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gn3dr
Part of things
Posts: 391
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Any more info on this please - is there a build thread somewhere? I like the arches - looking for wider arches for an MGB myself but I don't like the Sebring ones - they just don't look right I think. Those look almost like Mk1 Escort bubble arches?
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fraid not - just a random one on p/bucket will have a look at their album for more.....
Never sen pics of Bryn's mgb so don't know what he has done for arches to cover his mahoosive banded steelies. I've got an Idea for mine, depending on what wheels i go for and ho low it goes. not sure if its been done before so keeping it under wraps for now.
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wanted, 25th hour. Required daily, cash waiting
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wanted, 25th hour. Required daily, cash waiting
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Nathan
Club Retro Rides Member
Posts: 5,649
Club RR Member Number: 1
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If you have it off for the Chain tensioner then its worth doing the extra work, they are far better than the original and you can dial down the timing more precise.
Those arches look home made to me.
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Last Edit: Dec 9, 2010 10:11:05 GMT by Nathan
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is it is it worth going duplex on the timing gear? this was pretty popular on modded a-series as they are supposedly quieter, smoother running and longer lasting?
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wanted, 25th hour. Required daily, cash waiting
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gn3dr
Part of things
Posts: 391
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fraid not - just a random one on p/bucket will have a look at their album for more..... Never sen pics of Bryn's mgb so don't know what he has done for arches to cover his mahoosive banded steelies. I've got an Idea for mine, depending on what wheels I go for and ho low it goes. not sure if its been done before so keeping it under wraps for now. Bryn had an MGB - given some of his other projects I've seen on here I'd really like to see that. Those arches in the album look like a home made version of teh Sebring arches. The rear arches are missing the MG swage line which is a big improvement over the standard sebring type. My own plans hinge around fitting MX5 front and rear suspension so I may not have to go too wide on arches. I was eyeing up the nice subtle curved arches on an Audi A6 thinking they might suit. I want to try and use steel arches or even aluminium rather than fibre glass.
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Yep, have heard about Bryn's car but not seen it - sounds like a cracker
saw a passat VR6 4motion recenty, that had a nice gentle flair to it but i imagine parts will be expensive for that route, and prob not wide enough to cover something interesting.
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wanted, 25th hour. Required daily, cash waiting
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