dubstar_04
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| posted on 20/11/08 at 08:45 PM |
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750 mc locost engine build
I have recently bought a stock engine (711M-AA) for my locost racer and I was wondering if any one could advise on what is best to do to prepare it
for racing.
The engine is from a 80,000 mile auto mk2 escort, and on initial inspection it seems to be in excellent order.
I have built dozens vw of engines before so I intend to do all the spannering myself. I am more after a list of parts required, and maybe hints on
things not to do.
I am currently wondering things like:
what is the lightest standard conrod I could expect to find?
What are the options for the ignition system?
Things like that really if your willing to share!! 
Many thanks,
Dan
[Edited on 20/11/08 by dubstar_04]
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Syd Bridge
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| posted on 20/11/08 at 09:00 PM |
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You can start by looking at the Locost rules on the 750mc site. 750mc.co.uk
I'm going through this exercise at the moment myself.
Building a good Locost engine is not difficult, but tedious. A +.090 rebore is the biggest thing. It gives a few more cc's, but ups the
compression appreciably. Distributor from Aldon, or an early Fiesta/Escort with the Bosch or Lucas electronic distributor.
I'm still trying to work out what Randall does. Anyone know how far he advances the cam........? It's the only way of getting useable
power at over 7k revs.
Your turn matt. 
Cheers,
Syd.
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nib1980
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| posted on 20/11/08 at 09:05 PM |
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Well I'm in the process of removing a 1300 (ish) so I may have some internals that may be of use?
not strpiied the engine for inspection yet
forgot to say it was allegedly an ex race engine
[Edited on 20/11/08 by nib1980]
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Fozzie
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| posted on 20/11/08 at 09:40 PM |
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Read the 750mc technical regs for the Locost series thoroughly....
Tech Regs Linky
Click on Regulations.
It will define what you can and cannot do.
HTH Fozzie
'Racing is Life!...anything before or after is just waiting'....Steve McQueen
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procomp
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| posted on 21/11/08 at 09:10 AM |
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Hi
In general there is no big gains to be had. It's just a case of getting all the small details right.
Pistons. There is obviously the choice of over bore size but this will be dictated by what size pistons you can get hold off. Most go straight for
the +90. In next years regulations there will be two pictures of pistons that are legal for the championship. The older AE as per ford and the new AE
version that is the only one being produced from now on by AE.
Rods. There is not really that much between them overall. Just take the lightest one of your set and balance the other three to the same weight. One
ie the lightest must remain unmachined.
Cam. obviously the Kent P103/4 with the 750MC markings on the fuel pump lobe must be used. As for timing a few people chose slightly different figures
but all are within a few deg's of what Kent specify as STD. 108 - 114 is the range that is used.
Sump.This is an important area to consider. The desighn of sump from Burton's has proved to work very well and used by 75% of the field without
problem. There are a few who offer sump modifications that have PROVED to be very unreliable in desighn and also use a bodged pickup pipe desighn with
a bit of gauze wrapped around an open ended pipe. It is worth researching this area of the engine as it can lead to all your initial hard work and
effort being trashed within 4 laps if it's wrong.
Oil. there is only really one grade that takes the punishment 20/50. 99% of the field run the Valvoline VR1 as it is now called. those that have
tried to run a lower spec oil for bhp gains have all suffered problems.
Ignition. There are a few setups on the market such as Lumenition - Aldons - bestek - H&H ignitions. as well as using the Bosch distributor from
the fiesta. The most reliable setups are the Bestek and the H&H setups these use the Bosch distributors with an advance curve setup suited toward
the race aplication.
Cylinder head. Just one in good shape and fine fettle is sufficient. Read the regulations regarding what IS and IS NOT allowed in term of porting.
There is NO porting allowed but there is the very basic s allowed for matching the head and manifold faces. There will also be pictures of the
cylinder head face in the new regulations after a few anomalies where discovered this year. The cylinder head face must be flat and NOT chambered in
any way.
Just about all other parts such as rocker shafts etc etc can be brought from SKY FORD who now own the rights to the cross flow engine. Tel:
01442220200
Cheers Matt
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simes43
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| posted on 21/11/08 at 09:20 AM |
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Locost Wifes Tale Number One
Randall's rev in the high 7's. They don't.
Locost Wife's Tale Number Two
Randall builds special engines for the selected few. He doesnt.
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Syd Bridge
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| posted on 21/11/08 at 10:44 AM |
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I've worked my gearing on max 110mph, as has been quoted a few times as top attainable speed.
With a 4.1 diff, that's 7100+ rpm.
I stood and heard a top runner tell his mates, after qualifying, that he needed a shorter back end at Silverstone last. The diff they removed was a
4.?, I counted the teeth. I don't know what was going back in, but it was shorter than 4.?, and I didn't get a chance to count the teeth,
and he was muttering about not being able to get 8k rpm out of the thing.
I don't think he was 'putting on a show' just for me, as he didn't have a clue who I was.
Cheers,
Syd.
[Edited on 21/11/08 by Syd Bridge]
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Fozzie
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| posted on 21/11/08 at 12:39 PM |
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Ahhh but there's the rub!
Does he actually know at what rpm he was 'maxing' at? .....anyone can scream the wotsits off an engine......
I obviously have no idea of the guy you are talking about Syd, and I am really thinking out aloud here, but given the very limited cam that the racers
have to work with, I would think that max power would bottom out quite a bit below 8,000.
I know what bhp I have achieved, and my max out revs....... 
Just my very humble opinion of course and feel free to ignore.....
Fozzie
'Racing is Life!...anything before or after is just waiting'....Steve McQueen
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Syd Bridge
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| posted on 21/11/08 at 01:17 PM |
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He may have had a duff tacho.
But it didn't stop him changing the diff.
Cheers,
Syd.
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simes43
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| posted on 21/11/08 at 01:40 PM |
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The wind conditions were odd at the Snett round.
Usually you fight a headwind on one of the straights which keeps the revs down and bunches everyone up.
Dave B and I were lifting to avoid reving the nuts off our engines on the Revitt.
8K seems very high
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procomp
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| posted on 21/11/08 at 02:59 PM |
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Hi
I think it was Silverstone Syd was referring too.
There are quite a few guys out there running 4.4 ratio at some circuits with a 4 speed box. For this you do need to be able to pull best part of 8k
revs. It dose have some advantages at some circuits but not at others. This means that ideally you would be wanting to change diff ratio for different
circuits.
Possibly the best compromise is to run a 4.1 which means that you can run all circuits with lower max revs. And also means you do not need to carry a
spare engine. Or run a 4.4 and a 5 speed box.
Cheers Matt
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simes43
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| posted on 21/11/08 at 03:12 PM |
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Snett and Silverstone are pretty much the same for ratios.
A GT with a 4.4 at Snett or Silverstone is asking for trouble.
The engines produce very little over 6500 unless you have dodgy pistons and head.
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Fozzie
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| posted on 21/11/08 at 03:12 PM |
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quote:
Originally posted by procomp
.......... It dose have some advantages at some circuits but not at others. This means that ideally you would be wanting to change diff ratio for
different circuits.
Possibly the best compromise is to run a 4.1 which means that you can run all circuits with lower max revs. And also means you do not need to carry a
spare engine. Or run a 4.4 and a 5 speed box.
Cheers Matt
Matt, I said nigh on the same thing in a u2u to someone, about half an hour ago.... 
Still say though, screaming a more or less standard 1300 cross-flow engine to 8k, with that 750mc cam, is not at all good....
ah well 
Fozzie
'Racing is Life!...anything before or after is just waiting'....Steve McQueen
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Rob Palin
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| posted on 21/11/08 at 03:21 PM |
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I've heard a few people talk about revving up to between 7.5-8k rpm but never been sure if it's just normal paddock gossip or not. Those
people say they use a 4.44 diff at all circuits,too, but when I tried it myself I found it too way too short and ranted my crankshaft bearings at
Brands even with an oil cooler.
I think a 4.125:1 diff is the best all-rounder, but then I don't win anything so what do I know!
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procomp
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| posted on 21/11/08 at 03:29 PM |
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Hi.
It depends at what angle you are coming from. A blue printed engine with a good prep and ARP etc bolts will run too 9k before the bottom end lets go.
The cam that we run will produce no more power over 6500 revs but at the end of the day engine RPM = wheel rpm. By running the 4.4 you bring the gear
ratios closer together wich at certain circuits is a very good thing. Think about the caterham 6 speed setup.
If you stand at the end of the straights at snett donny silvertone you can quite easily here who is running a 4.4 and who is running a 4.1. Hence you
will see people such as me Muarice And a few others stood watching practice 3/4 of the way down the straights watching where people are changing gear
etc.
As i say you can run a 4.4 at almost every circuit with a 4 speed but you will be rebuilding the engine and box regularly. Hence run a 5 speed or a
4.1 and a 4 speed.
Cheers Matt
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Fozzie
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| posted on 21/11/08 at 03:47 PM |
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Matt, I was under the assumption, that we could only blue print 'so far', not totally...... I am sure (but could be wrong) that I have
read that somewhere?
Mind, I did build in 2002-4.....so something in the tech-regs back then?
Fozzie
'Racing is Life!...anything before or after is just waiting'....Steve McQueen
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Syd Bridge
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| posted on 21/11/08 at 07:31 PM |
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Geez, I didn't mean to stir things up like this!!!
Has anyone seen the debate on the Westfield forum about all the breaking Raceleda/MNR uprights? Loads of 'em coming out of the woodwork with
breakages. ( I won't tell 'em 'I told you so', a couple of years ago.)
The numbers say that 8k would be about 115mph, but the power probably isn't there to do this. ( At least not without a strong following wind and
downhill!)
I've been through all this with the boys' Mini's, and everything tells me to run a 4.1. My old saggy backside itches and asks me if
I may not be doing the right thing.
I know what I did with the Mini's, and why, so that's how I'll go forward.
Cheers,
Syd.
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Fozzie
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| posted on 21/11/08 at 07:47 PM |
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I, for one, don't think you have stirred things up Syd!
I think it is good to talk about these things now and then.
I hope it helps newbies preparing their cars to understand why people use different diffs and the reasons behind it.
I think a 4.1 would have been my choice if the car had been for track only......
As Matt rightly said, taking it up to 8k with 'that' cam/restraints regularly, well, you would need deep pockets/loads of spare boxes,
engines and time.
Fozzie
'Racing is Life!...anything before or after is just waiting'....Steve McQueen
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procomp
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| posted on 21/11/08 at 08:06 PM |
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Hi
Which is why we are running a 4.1 in the Lewisham college BIO car next year. Budget that is.
Cheers Matt
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D Beddows
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| posted on 21/11/08 at 09:17 PM |
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The secret to building a good 'Locost racing engine' is to know how to blueprint an engine properly.......end of....oh and know all the
FFord tricks obviously I'm pretty sure I know who Syd has been referring to and I've heard the astonishingly short diff stories as
well and despite all that they're not actually winning anything much are they
9k on standard 1300 internals eh Matt? that's nearly as good as your 'it's easy to get 160bhp out of a crossflow' post
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procomp
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| posted on 22/11/08 at 10:30 AM |
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Hi Dave.
The good old super sport Fiesta as used extensively in the 1300 class for oval racing. The bottom end with ARP bolts was good for 9k as where the
1300 MK2 escort rally cars. It was the top end that needed all the trick bits. The bottom ends just needed bearings and the cranks crack testing every
rebuild. The point of the comment was that the bottom end being such a short throw crank will go to 9k without falling apart If built correctly and
compentently.
Cheers Matt
Oh Ps 1600's with a 244 cam and a down draft carburetor. 160bhp As run by half the field in KITS when we had the old Class B circa 2000. And
those engines still hold a couple of the lap records i think.
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D Beddows
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| posted on 23/11/08 at 06:50 PM |
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quote:
If built correctly and competently
No, I'm with you but I'd bet most people would miss that last phrase
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Fozzie
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| posted on 23/11/08 at 08:26 PM |
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Guys......the OP is a newbie preparing for the Locost 750mc series......he has to build within the constraint of the technical regs...for that
series.......
Talk of building screamers, steel cranks, dry sumps, different cams and full blue print, is hardly helping the OP, more like, in all probability,
confusing him!
Fozzie
'Racing is Life!...anything before or after is just waiting'....Steve McQueen
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D Beddows
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| posted on 23/11/08 at 09:14 PM |
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No, I'd agree with most of that APART from the blueprint bit - you can't properly deck the block because you're not allowed to
machine the top of the pistons and one con rod has to remain standard BUT apart from that knowing how to blueprint an engine properly is the only way
you'll get an advantage and tbh you'll really need 2 or 3 1300 engines to mix and match parts and several bearing kits to get enough
parts to do it properly unless you have a full machine shop on hand.......... been there, done this a lot ......
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Fozzie
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| posted on 23/11/08 at 09:31 PM |
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Totally agree with that Dave!
Fozzie
'Racing is Life!...anything before or after is just waiting'....Steve McQueen
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