Traveller Tuning

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panky
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Re: Traveller Tuning

Post by panky »

callyspoy wrote: Sun Dec 23, 2018 12:04 am Panky, i didn't want to suggest it as i hadn't done it myself before, but that is what i would do also.

Slight thread hijack...
My own Minor is a 998cc, 940 head, 1098 cam, HIF38 with K&N cone filter, AAA needle, Ital twin outlet exhaust manifold going into a 1.25" exhaust system.

Could the exhaust be restricting the engine enough to mean the AAA is too rich? I know it is too small diameter for optimal power, and i have a 1.75" RC40 twin box exhaust system to modify and fit, but i thought it would be ok for now, but the plugs definitely do suffer a bit. The tip is a decent enough brown colour, but it is quite black everywhere else.
I don't want to buy a leaner needle, only to find that the larger exhaust will allow it to breathe so much better that the AAA will be more suitable. (Partly because i accidentally sold a spare HS4 without removing the AAU needle that i had, idiot).
Another thing to add is that the 1 3/4" exhaust is too big for your engine and you could actually loose power, 1 1/2" all the way through is plenty big enough - which is what I have on my 1098.
So many things have been changed from standard that it will be difficult to get an ideal needle/spring set up off the shelf, best you can hope for is somewhere near but ideally a rolling road session is needed to set it up properly. It could be that a custom needle will be needed to get the profile required throughout it's full length.
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callyspoy
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Re: Traveller Tuning

Post by callyspoy »

Hi Panky,
Cheers for the update.
The general consensus on the Mini forum is that a 1.625" exhaust is the optimal size, with 1.75" being the general preferred due to availability.
For my build, i have had to juggle a compromise between cost/performance/aesthetics.
To me, my current system at 1.25" is too small, and the rear silencer (a Triumph Herald one!) Is not a straight through box.
With that in mind, and with the relative tune of my engine, coupled with the funds i have (limited), the 1.75" should tick enough boxes.
I do plan a cam change at some point soon, i have pretty high compression (decked block and flat top pistons) so it should appreciate the 1.75" straight through system more than my current one, even if it isn't perfect.
All the compromises that i never had with my first Minor, 11 years ago as a 21 year old, as i just put everything on a credit card before 😂. Now, a wife and 2 kids later, that isn't an option, thankfully.
panky
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Re: Traveller Tuning

Post by panky »

Understand totally and yes your current exhaust wont be helping. If you've got a windows PC then WinSU is a worthwhile investment, the free version allows you to select the engine and tune you have (or want) and gives a detailed read out of BHP, torque, estimated top speed and acceleration along with a needle comparison graph. Pay a £10 registration fee and it also lets you compare reccomended needles for your set up. I've not registered yet so don't have that facility but the free version is very useful.
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Chipper
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Re: Traveller Tuning

Post by Chipper »

I have recently fitted a 1.5" diameter Maniflow LCB and exhaust to my 1275 Traveller, and it has definitely improved things compared to the previous standard Minor 1.25" system. It was an excellent fit too. :D

Has anyone tried a set of 1.3/1.5/1.7 roller rockers, such as these:

https://www.minisport.com/1-5-1-mini-ro ... ckers.html

They are supposed to give similar power increases to fitting a high-lift cam, without the hassle of having to remove the engine.
Maurice, E. Kent
(1970 Traveller)
panky
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Re: Traveller Tuning

Post by panky »

I know the jury is divided on these among Mini owners. The consensus seems to be you get power gains at the top of the rev range but loose out on torque and they can increase wear on the cam, I prefer a torquey engine rather than a BHP screamer, much nicer to drive. They aren't cheap and personally I would plumb for something like an MG metro cam with a nicely flowed head - which just happens to be what I've got in my Mini and it goes extremely well :D
The AC Dodd cams are very well thought of too.
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callyspoy
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Re: Traveller Tuning

Post by callyspoy »

I agree with Panky regarding the rockers. They can have a good improvement, but for the cost, certainly better mods out there.
The maddest A series i have had was a Mini 1098.
It had been rebored with Hillman Imp pistons to 1215cc, 940 head, Kent 286, maniflow inlet and full exhaust, HIF38 and K&N in a filter box. The crank was centre strapped and had been balanced. I bought the bottom end already done, i just fitted the head and timed it all up with vernier timing gear, so can't say what had been done to the bottom end.
This was my favourite engine as the torque was phenomenal. It took out all the harshness of the 286 cam and pulled like a train up to near 7000rpm, where my fear of breaking the engine was the limiting factor.
I would love to recreate this engine one day in a Minor, as it wiped the floor with all standard and most mildly tuned 1275's. That was able to cruise at 80 and still have plenty to accelerate briskly.
Again, when i was a younger, more foolish man.
Kittyhawk
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Re: Traveller Tuning

Post by Kittyhawk »

I have been trying the mini airbox with the HS2 and it looks like there is insufficient clearance for the choke cable under the bottom of the airbox. It is I think, supposed to enter downwards to the carb through the hole in the lug as shown in the photo. Also, my carb has the diagonal for the mounting to the manifold the opposite to the manifold I have, but I am going to remove the inlet part and get an alloy one. There seem to be many of those from different suppliers, such as MiniSpares and Somerfords, all at much the same price. Are they all much the same? They appear to have 4 mounting holes for the carb, so I am assuming mine will fit?
I don't think I can use a standard Mini abutment plate, as they are for the other diagonal. My HS4 has the float chamber on the side facing the front of the car and the linkages at the rear, the same as the present HS2. I think I will have to fabricate something to fit. The carb has a fairly strong throttle return spring coiled concentric with the butterfly shaft. Would I be better off using the long return spring down to a bracket as per my present one?

Regards
Roger
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panky
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Re: Traveller Tuning

Post by panky »

The HS4 will fit on the four stud inlet manifold and the abutment plate for that carb, not HIF type, has an attachment to direct the choke cable under the air box, you may need a longer choke cable though.
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Kittyhawk
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Update

Post by Kittyhawk »

This is my first A-Series overhaul, so all hints and tips welcome. The engine is almost ready for removal. I have stripped all the ancillaries off including the head. A quick inspection of the cylinders shows a lot of oil in them, with pooling on the piston crowns. I am assuming it must be from failed oil control rings, as the valve guides were renewed when I had the head converted to unleaded last year. It would certainly account for the very high oil consumption.The bores are standard size and I have measured them with a bore gauge and there does not seem to be any ovality present. They are not scored at all, but quite shiny (glazed?).
When I was draining the coolant, I got nothing out of the drain plug at the left rear of the block. Could that be blocked?

There seems to be mixed opinions on whether to lift the engine out while leaving the bumper and grille in situ, or to remove the latter?

The engine number confuses me. I thought a 1098 should begin with 10, but I understand that Gold Seal replacement engines can start with 8G? It certainly isn't the one in the log book!


I will report further when the engine is out.

Roger
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Chipper
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Re: Traveller Tuning

Post by Chipper »

Yes, it probably is a Gold Seal reconditioned unit - see foot of this link, which confirms the 8G identification:

http://www.mginfo.co.uk/upgrades4mgs/fi ... umbers.pdf

Pools of oil on top of the pistons may be due to worn valve guides and/or valve guide seals; with the valve springs removed, check to see if there's excessive play between the valve stems and valve guides.

If you think the bores are OK, you can use a glaze buster to remove the glaze and restore honing marks (you don't want the cylinders completely smooth).
Maurice, E. Kent
(1970 Traveller)
washer-bottle
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Re: Traveller Tuning

Post by washer-bottle »

I use an air filter from a Triumph Toledo with a HIF38 if that helps.

download/file.php?mode=view&id=7623

Al
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Kittyhawk
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Re: Traveller Tuning

Post by Kittyhawk »

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Engine ready to come out. Got the crane today so out it comes tomorrow. As I have not done this before, do I need to support the gearbox in some way with a jack or similar?
philthehill
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Re: Traveller Tuning

Post by philthehill »

You will need to support the front of the gearbox otherwise the front of the gearbox will smartly drop when the gearbox first motion shaft exits the clutch.
You can use a jack or similar.
Just make sure that you do not put any strain of the first motion shaft or clutch assy.
Best to remove the clutch relay shaft.

Kittyhawk
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Re: Traveller Tuning

Post by Kittyhawk »

Thanks. Glad I asked.. Interesting that Haynes doesn't make any mention of this in the section on removal without the gearbox?
philthehill
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Re: Traveller Tuning

Post by philthehill »

A lot of manuals including the BMC wksp manual for the Minor do not include minor :wink: details.

Kittyhawk
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Re: Traveller Tuning

Post by Kittyhawk »

Update: The engine is out and completely stripped down. The crank is in good condition and just needs a good clean and polish and new bearing shells. The pistons were in a very poor state with 3 out of 4 showing signs of past seizure, with bad vertical scoring. They have been binned and the block has gone for a a +20 rebore. I found the crankshaft thrust washers to be a pair of standard and a pair of +003. Given that standard sets cost a third of oversize sets and you have to buy 4 in a set, is it best to wait until I start building the engine back up and measure the float, rather than trying to buy like for like? Pistons and rings are being ordered together with a new oil pump and timing chain.
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philthehill
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Re: Traveller Tuning

Post by philthehill »

Bad luck with the pistons.

As regards the thrust bearings - it is ok to mix and match the thrust bearings to get the right end float provided that the same thickness thrust washer is fitted top and bottom to either the front or rear thrust face.

I would wait until the crank is fitted and the end float is measured - you may be able to re-use the thrust bearings you already have without having to buy new ones.

Phil

Kittyhawk
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Re: Traveller Tuning

Post by Kittyhawk »

Thanks Phil.

I am now at the stage of fitting rings to pistons and pistons to bores. In Haynes it suggests fitting a ring to the bore and measuring the gap. Does this apply with new pistons and rings?
oliver90owner
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Re: Traveller Tuning

Post by oliver90owner »

Always check. If there was too little gap (unlikely, but possible) the rings could seize the engine or score the bores, if the ring gap decreases to interference on warming up.

If undersize rings were fitted, the gap would be too wide and the rings would not fit the bore as a circle. Over-size rings should be obvious as they should not fit the bore.
pgp001
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Re: Traveller Tuning

Post by pgp001 »

Put a ring down the bore, and then slide a bare piston down onto it to ensure it is truly square bfore measuring the gap with feeler gauges.
If you are using existing bores dont forget to try the ring at both ends.

I dont have a copy in front of me but suspect you will find the desired gap in the workshop manual.

Phil
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