Markp
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 posted on 3/4/04 at 08:04 PM |
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xflow speed???
Hello all,
I have a 1600 xflow and it was fitted with the four speed box that got up to 100mph, I have since put the type 9 five speed box in and it only gets to
80mph at 2500revs, the car feels slugish and struggles at top speed, although it's only at 2500 revs, it is struggling to get any higher.
Is this the norm with the five speed box and an old engine or is there something amiss? Any ideas what??
Mark
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Mark Allanson
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| posted on 3/4/04 at 08:09 PM |
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What is your diff ratio? sounds like you are a bit over geared in top. Good for economical cruising though.
What is the top speed in 4th?
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Markp
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| posted on 3/4/04 at 08:38 PM |
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Mark
It's a escort mkII timken type with a 3.54 ratio, it's off the escort ghia I got the engine out of.
In fourth gear it's not too bad,change to top gear at about 60-70mph but still feels that it should be giving more.
When cruising at 80 in top it's a struggle to get it any higher that 2500 revs, the most it's gone up to is 3000.
Cheers
mark
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Mark Allanson
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| posted on 3/4/04 at 09:42 PM |
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Give me your tyre size, and I'll do the workings out
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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stephen_gusterson
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| posted on 3/4/04 at 10:40 PM |
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many fords acheive top speed in 4th.
the book for the car i got my v6 donor from states top speed in 4th.
just change down a gear! 
atb
steve
ps - its power that creates speed - not gears - did you expect more gears = more speed?
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Markp
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| posted on 3/4/04 at 11:12 PM |
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stephen_gusterson
Not really, i expected it to be more comfortable in top gear, surely a 1600 shouldn't struggle, I know it's got it's age against it
but I can't seem to except that it won't rev further than 3000, it must have more in it than that?
Mark Allanson
I'll post the tyre size tomorrow when it's light (can't see bugger all when it's dark
 )
Thanks for the help.
Mark
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Tblue
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| posted on 3/4/04 at 11:22 PM |
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Mark A
I would presume that the top speed in fourth was 100mph, same as with the four speed box!
My mate's W******** was the same with a 3.54. We put a 3.89 diff in it.
[Edited on 4/4/04 by Tblue]
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JoelP
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| posted on 3/4/04 at 11:27 PM |
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sounds like a diff problem rather than an engine power problem, cos 80mph at 2500rpm means it is geared for a top speed of 160mph or more - its not
going to manage that driving down the white cliffs of dover!
i'd up the ratio, you want the geared theoretical top speed to be similar to what you expect the power to manage. ie, 100 to 120mph. maybe less
for a 1600 i suppose.
then again, you dont want to be bouncing off the limiter at 80 either...
[Edited on 3/4/04 by JoelP]
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david walker
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| posted on 4/4/04 at 07:33 AM |
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The 4 speed box has a top gear ratio of 1:1. The 5 speed is 0.89:1.
4th gear in your 5 speed T9 box has a ratio of 1:1.
Apart from the fact that the T9 is quite a bit heavier, the speed achied in top with the 4 speed will be same as 4th with the new box.
To achieve same top gear ratio you did have you'll need to change to a 4.1:1 diff. - Or tune the engine!
Dave Walker, Race Engine Services - 07957 454659 or 01636 671277
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Markp
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| posted on 4/4/04 at 08:26 AM |
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Thanks for al the replys so far,
If I change the diff, does that mean I will have to get the speedo recalibrated? Can I just change the internal bits of my old one or do I need a
whole new unit?
Apart from a new cam and carb what other mods can you do to the xflow?
Sorry to sound dumb over this matter but I've never really gone in to the tuning side of things.
Mark
[Edited on 4/4/04 by Markp]
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madforfishing
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| posted on 4/4/04 at 09:05 AM |
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You could get some work done on the head. Various degrees of head work will give you larger valves / porting / polishing. You could get the valve
seats done too, you can use unleaded fuel then. Bear in mind that this will COST you though. Might be worth weighing up if this is actually worth it
- compared to a more powerful engine. Some worthwhile reading is 'Tuning and Revbuilding Ford's Crossflow engine' (Wallage &
Wallage - see ebay / amazon).
If you start tuning your crossflow, bear in mind if you haven't rebuilt it previously then you have to be sure it's spot on or you new
state of tune will wreck it in no time at all.
Sorry to hijack your post, but I have a similar situation. I was just offered a Sierra 5 Spd box for free. I am running a 1300 xflow coupled to a
1300 box and diff. I have a spare 1600 engine which I'll fit later. Given what MarkP said about his redundant 5th gear, has antone tried the
following combination ?
1600 xflow
5 Speed Sierra box
1300 diff. ? ? ?
Also is the Sierra box longer than the standard xflow 1300/1600 item. My current gear shift position is hardly ideal. Maybe I could kill 2 birds, as
it were.
It's no problem with having to move the gearbox mounts if necessary. Will this also vring my shifter position further backwards ?
Help.
[Edited on 4/4/04 by madforfishing]
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britishtrident
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| posted on 4/4/04 at 09:31 AM |
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General guide diff ratios for engine size road use.
1100 4.4 to 4.04
1300 4.11 to 3.89
1600 3.89 to 3.77
1800 3.89 to 3.55
2000 3.77 to 3.33
2000+ 3.55 to 3.00
A seven as the aerodynamics of a barn door, 5 gear is really just an overdrive top speed will be reached in 4th
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Markp
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| posted on 4/4/04 at 10:33 AM |
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madforfishing
Hijack my post will you??
That is the main reason I changed the gearbox in the first place, the gear shift was a pain in the arse. When I put the 5 speed in it moved the
position closer slightly But the just over £80 later and the westfield gear lever extention was fitted on now I'm very happy with the
position (it's how in my eyes it should be)
Hope this helps
Mark.
PS. is it worth having it made in to unleaded, I was under the impression that they altered the timing and this could make it slower, How reliable
would the engine be if it was converted (WOuld the engine actually like the unleaded petrol)
I know I'm dumb
[Edited on 4/4/04 by Markp]
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britishtrident
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| posted on 4/4/04 at 04:11 PM |
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The only 3 reasons for not using a 5 speed in a 1300 are weight -- is dammed heavy, it is bulky particularly the the bellhousing, also the propshaft
is a different size.
Rob Lanes site has a picture of both boxes side by side.
To mate the 5 speed box to an engine with a 190mm 7.5 clutch you need the following
Clutch Plate --- Hillman Avenger
Pressure plate --- Your existing pressure plate MIGHT clear the support tube on the 5 speed input shaft but I used an early Sierra 1.3/1.6 for cars
with removeable bellhousing.
Release bearing --- Sierra 5 speed or 4 speed removable bellhousing type.
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madforfishing
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| posted on 4/4/04 at 07:58 PM |
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BritishTrident,
Thanks for that info. I think you've helped us both out.
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Mark Allanson
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| posted on 4/4/04 at 08:13 PM |
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quote:
Originally posted by Tblue
Mark A
I would presume that the top speed in fourth was 100mph, same as with the four speed box!
[Edited on 4/4/04 by Tblue]
Thats why I asked the question, if it wont pull 100mph in 4th, it is a different problem, probably connected with the box change, rather than with the
ratios inside. I still think is the lack of torque at 2500rpm to overcome wind resistance and rolling resistance. Not a problem if 4th does the job,
he will just have a VEEEERY relaxed drive in 5th (economical too!)
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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stephen_gusterson
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| posted on 4/4/04 at 10:12 PM |
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most car engines have power and torque max levels above 3,000 rpm. So if your car is geared in top to max out at 3,000 rpm, you are not in the power
band. Your 90hp engine may only make 60 or so at that level. Thats why cars have gears - allows the engine speed (and resulting power) to be matched
to road needs.
a given weight, and wind resistance will need a given power to reach a given speed. Obviously that power doesnt exist at 3,000 rpm on your engine to
allow further acelleration.
Many years ago I read that a 38 hp mini needs 8 hp to do 45 mph. The max power allows the 75 top speed a mini had.
If you dont make the revs, you dont make the power, and the car wont make top speed. If you change down a gear or two and the car acellerates
further, its a sure fire indication that your engine is fine and your diff is wrong. If it doesnt acellerate, your engine is maxed out.
atb
steve
[Edited on 4/4/04 by stephen_gusterson]
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Markp
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| posted on 4/4/04 at 10:38 PM |
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Thanks for all the info/help.
So, if I change the diff........Can I just put the internal gubbings in from another axle and will it effect the speedo???
Mark
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JoelP
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| posted on 5/4/04 at 08:31 AM |
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yes, it will affect the speedo. Have you completed the SVA yet? if not, it might be worth leaving it, providing the speedo is currently reading
correct!
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