Mansfield
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| posted on 20/7/05 at 09:29 PM |
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Is the DOHC really that bad?
I am getting fairly close to my build now, but still cannot decide on an engine.
I cant afford Zetec + carbs + ecu etc or a bike engine and I cant get excited about a pinto.
The more I look at it, the 2.0i DOHC seems to fit the bill on price, bhp, unleaded and availability, but I know opinion is divided - generally more
negatives than positives. And no one likes the MT75 box much either.
I know its up to me at the end of the day, but I need some help because I am dithering.
So, as the title asks, is the DOHC really that bad?
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aweekes1
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| posted on 20/7/05 at 09:56 PM |
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I had a Sierra with the DOHC lump a few years back. The engine pulled strongly and had no problems getting me into trouble  I think the lump is
quite heavy but then again the Pinto weighs about 20 tons If you have one to hand or can get one cheap and can't stretch to the Zetec setup
you want then do it. If it's that bad you can always change it later?
This lump was used in the good old Granadas also and I think it's got great big valves and is grunty down low. It's also a little
different to the norm so you won't be following the pack (good and bad I suppose?)
Do it then let me have a drive
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Mansfield
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| posted on 20/7/05 at 10:09 PM |
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I agree with the pull, back in the day I used get out in a 2.0GT Sierra pool car - I was always quite impressed.
As for not following the pack, most of the pack on here seem very clued up. That is what puts me off it a bit.
I find I wander around with wish lists in my head about all aspects of the build. I guess a lot of people do. But I am getting tired of this and
want to start building. I hope once I DO start, then some of the choices will sort themselves. I hope...
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Volvorsport
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| posted on 20/7/05 at 10:37 PM |
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fit a volvo engine - i gave a DOHC away the other week !!!
www.dbsmotorsport.co.uk
getting dirty under a bus
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MikeRJ
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| posted on 20/7/05 at 11:00 PM |
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quote:
Originally posted by Mansfield
I am getting fairly close to my build now, but still cannot decide on an engine.
I cant afford Zetec + carbs + ecu etc or a bike engine and I cant get excited about a pinto.
You can pick up a 1.8 or 2.0 Zetec for very little money if you keep your ear to the ground. There are usualy several on Ebay.
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zetec
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| posted on 21/7/05 at 06:44 AM |
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If you have a decent DOHC and you don't need to buy anything to get it working in the car then use it. The only time it does not make sense is
when you need to buy carbs and ECU, or you need to rebuild the engine.
The cost of a second hand zetec is low, and 9 out of 10 can be fitted with nothing more than a oil change and perhaps a water pump swap. If you need
to buy carbs for the DOHC then you might as well buy them for a Pinto or zetec.
The MT75 gearbox works just fine, Westfield have been using it for years. Mine feels like new still as is straight out of the donor. the other good
point is the ease at which the gear lever can be relocated in relation to the gearbox.
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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NS Dev
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| posted on 21/7/05 at 07:26 AM |
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Yes, it is that bad!!!
I have had a granada and sierra with this engine in and hated both! (ok, this was in comparison the the v6 versions of both)
I have also done a number of head gaskets and surveyed the damage done by knackered camchains and tensioners.
The pinto, though heavy and inefficient, has the saving grace of being simple to work on and having cheap parts readily available, unlike the DOHC.
Just stick a vauxhall XE in it though, much simpler!!
Get an astra GTE 16v for £200 with rotten arches. take the engine and injection system out, then ebay the digital dash and interior and you'll
make half the money back. Spend £50 of that on a Manta 1800 or carlton gearbox (which both bolt straight onto the 16v) and the other £50 on a
propshaft. (chop the front off a manta/carlton one and the back off a sierra/escort one and get a new tube welded in and balanced, £50 at your local
propshaft place)
Use a Carlton 2.0 friction plate and the astra's pressure plate and the clutch is sorted. Keep the std injection on the engine. Dunno if
it'll fit but if it won't then neither is the DOHC system likely to. The std Bosch Motronic system on the astra only needs 4 external
connections, permanent live, ign switched live (to turn the ECU on), connection to the fuel pump (via fuse) and rev-counter.
[Edited on 21/7/05 by NS Dev]
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DarrenW
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| posted on 21/7/05 at 08:00 AM |
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I think the main people dont like the DOHC due to potential mechanical failure problems and lack of tuning potential. Having said that i bet there
have been thousands out there that have been looked after properley and never caused the owners any problems. If you arent bothered about tuning then
there is no real reason why it cant be used.
I was reading a small article in July's Kit Car mag that Westfield have just released a plenum for the Zetec that allows the std injectors and
rail and coil pack etc to be used, approx £150. This means a Zetec install should be possible even cheaper than before. ECU, clutch, water pump etc is
all that is then required.
Ive fitted Pinto due to budget restrictions and 'cos it has potential for further tuning later if the bottom end fails or i fancy more power. I
would have preferred Zetec but decided to keep the build simple for now. I would have used the donors DOHC if the head gasket hadnt failed (i tried to
fix it but found a porous liner upon closer inspection - this gave me grave concerns about the reliability of this engine).
At the end of the day it is your choice and if your lump satisfies budget and is OK then why not. You can always plan a winter upgrade in the future.
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Chaz
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| posted on 21/7/05 at 09:47 AM |
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I think most people have covered the relevant adv and disadv of using your DOHC. About a month ago i decided to change from the DOHC to Zetec as i was
getting fed up of the problems i encountered (see a thread called Drastic Measures!).
The reasons for my change, in order of my priority were;
1. Availability was poor for kit car orientated parts e.g exhaust manifold, engine mounts, and inlet manifold (all will be custom which equals
expense)!
2. Upgradability = zero (apparently if you try any tuning on the engine then no.4 cylinder always generates cracks. But yes, it does have good torque
already.
3. Going into an MK i had problems where the block would have interfered with the steering linkage (its quite a big unit). Plus i had the height
factor (may only apply to MK) the sump stuck out the bottom of the chassis by around 10cms! The bonnet bulge is in the wrong place to take advantage
of it aswell. So for me, an all round nightmare!
4. It has to look right. Personally i couldn't see this engine in my car for long. I was planning the upgrade even before i'd built it. So
i decided, well i should just go for it now!
My cost so far for Zetec build;
L Reg 1.8 Zetec Escort Donor 68000miles (Ebay £51)
Exhaust - full (£350-400) but you would need a custom one for the DOHC anyway.
Clutch friction plate (£30), spigot (£10) and westfield bearing (£approx 40).
Extras that you can make do without;
R1 carbs, manifold, and filter (Boggs Bros £400) - for Zetec you can use the new plenum from Westfield and keep the injection (cool option i
think).
But its always up to you, cos its your build!
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NS Dev
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| posted on 21/7/05 at 10:10 AM |
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Meant to say after my "pro vauxhall power" rant above, that obviously the Vauxhall lump is 150 bhp as std and a lot more with no internal
changes. (mine is 176hp @wheels, just over 200hp @ flywheel on std internals, including std cams etc)
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ChrisW
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| posted on 21/7/05 at 10:15 AM |
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The Zetec is nowhere near as expensive as people make out. I've said this a million times before, but the ECS2 unit off a late Escort CVH can
be had for a fiver from a scrappy and will run the ignition side of things with just four plugs to connect and a live and earth feed. Then all
you've got to do is sort out fuelling. 40's are the best answer but obviously you're looking at £200 upwards, but you can go for
bike carbs to keep the cost down or even chop down a Fiesta Zetec inlet manifiold and fit a carb to it.
Chris
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Lozec
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| posted on 21/7/05 at 02:01 PM |
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Why don't use the original ECU from the zetec? That'll solve a lot of problem and keep cost down! (can't see why people are
strugling with old webers when the working EFI is for free!
//Lozec
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MikeRJ
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| posted on 21/7/05 at 03:57 PM |
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quote:
Originally posted by Lozec
Why don't use the original ECU from the zetec? That'll solve a lot of problem and keep cost down! (can't see why people are
strugling with old webers when the working EFI is for free!
//Lozec
The problem is the inlet manifold/plenum on the Zetec is a massive affair that sits down the side of the engine, and basiacly isn't really
suitable for use in a locost.
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big_wasa
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| posted on 21/7/05 at 06:55 PM |
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If I said that the Dohc was great could I flog you mine
The engine is great in the sierra but a touch large for a 7 although like most challanges of the build this can be met.The engine has a lot more
torque as standard than a pinto .
Due to lack of demand there are no of the shelf parts and spaeres are dear..
If the engine does go bang dont fix it bin it .You will get a runner for less than the cost of a set of spark plugs ,let alone Head set /chain
tensioner and odds and sods..
I like the gearbox beter than the type 9 and as said its easier to move the gear stick..
Depends what you want out of the car really????????????
There is nothing about the dohc that cannot be overcome. There is just less reasons to make you try
To give you an idea I didnt bother trying so I borght a zetec insted...
As I said I could flog you a full donor
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Mansfield
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| posted on 21/7/05 at 08:10 PM |
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"There is nothing about the dohc that cannot be overcome. There is just less reasons to make you try" is a very eloquent way of putting
it.
I am pretty much settled on a +4, at least 1" higher as I have a big arse and big feet. I was kind of hoping some of the size issue would be
absorbed with this size chassis. I meant the engine. Not my arse.
I am thinking about your car, or at least parts of it.
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big_wasa
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| posted on 21/7/05 at 11:31 PM |
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quote:
Originally posted by Mansfield
I am thinking about your car, or at least parts of it.
Well its sat and going to waste.
Ive offered it on here acouple of times.
engine is carbed version so no injection to worry about..
Next holliday I get I was going to strip the few bits I may aswell have from it and get whats left collected as scrap..at the mo it may still have
mot..Its had a new clutch and I have a full headset aswell...
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