nath.clarke

Hi, Looking for help as trying to build 1st cosworth engine for my mk1 escrot (mexico). I have got the following bits:

yb 2wd cylinder head with std cams, not been skimmed.
205 pinto block,
escort cosworth pistons,
twin 45 DHLA carbs.

The last means idealy I want N/A.
Is their anything special I need to consider for the conrods and crank I will need?

Can I skim the head down sufficiantly to get about 12:1 c/r. will I need to put valve cuts in the pistons?

Would love 250bhp, happy at 200

Trying to do on absolute budget!

Nath

Ebonycossie4x4

iTrader: (4)

when building this what is the motivation for not going turbo.

Ive never driven a turbod mk1/2 are they uncontrollable on boost?

I just cant see why anyone would wanna go N/A when it would be so easy in youre situation to go turbo!

nath.clarke

Long story. Bought the carbs 9 years ago (centimental circumstances), when it was going to be zetec powered. It is now definatly going to be cosworth powered (definatly to vauxhall, dutatec, f20c, boa powered.... DFV would be interesting but not going to happen. Short answer, I already got the carbs.

Long answer.

I could use these carbs with a turbo in the same way lotus did with the elan(?). Lot of hard work, rare car bits. Ford thought injection was a better way back in the day!

Roots blower! Would be interesting but masses of fabrication (Have got good machine shops on tap!). Loads of work.

Esso blue (MK 1 rally car) was only 210bhp, and that had massive chassis mods, which I cannot afford and was set up by proffesional rally crew, and it was a new car! 300bhp+ would be lunacy in a 35 year old chassis with a stock suspension layout (apart from my pnumatic dampers!).

now this may sound crazy (er) but I am keeping the 1760 crossflow (which was mental at 130bhp) and keeping everything reversable (apart from trans tunnel which will be from an auto) for when I am elderly. Once I start thinking about 300bhp, quadlink suspension, rolecage, lsd will all become neccessary. Apart from the cost, the welding work is not reversable.

Another crazy idea. I have red that you can use 1800 diesel rods which give a greater crank length, I could then turn my escort pistons down (have lathe!) to meet top of block. Do the valves protrude far under head when out? would recesses be neccessary in crowns?

Trying to do on budget, so would this be a cheap way to power??

open to sugestions!

Sorry, I appear to have rambled.

Simmo

iTrader: (20)

Don't skim down your unskimmed head... sell it to someone who will pay good money for a meaty head for their turbo engine (LIKE ME! ) and buy another cheaper skimmed head... simples!!!

t4 and greys

iTrader: (5)

your head will need a lot of porting and poloshing to acheive good bhp figures imho as this is essential for the n/a build (incedentally cosworth originally intended the yb head to be for na) but had to close the ports slightly for turbo use as was deemed to wild)
thats why a stock head will need good porting to run n/a

also to be honest i wouldnt even bother with the 45,s mate bare essential to have 48,s in my experience ...

as for the pistons much easier to just buy a set specifically for the job


in a nutshell mate is near on impossible to build a decent n/a lump cheaply
oh and revs nicely to 10k


oh and i personally own a jondell specced n/a lump with gravel spek head and produces 235bhp on 48,s oh and revs nicely to 10k

t4 and greys

iTrader: (5)

forgot to say aswell a lot of people use 2.8i capri pistons too as a cheap way of doing it ...
google it mate lots of info out there on the web

also the likes of www.turbosport.co.uk has a lot of info and usefull pointers too mate

nath.clarke

If anyone has a n/a head, that does not require skimming then I would be interested in swapping!

nath.clarke

Next few Questions......

I have started 3d modeling the piston, conrod and head and crank because: I can, I'm sad, theres sod all else to do during my lunch hour!

Could anyone tell me the throw on a cosworth crank? How thin can you take a piston crown?

In reply. I have bought the pistons (2nd hand all be it) and they were delivered yesterday. Is there absolutly no way they can be used?

What can I get away with porting to? Are there any books that can tell me the angles and depths involved? or does anyone know?

Simmo

iTrader: (20)

I've just got rid of a head that would've been ideal!

But i'd still be interesting in buying your head if you were to get rid!

nath.clarke

sorry, not getting rid, its took me 10 years to finaly get around to getting one!

t4 and greys

iTrader: (5)

based on std specs

bore size 90.82 mm

stroke 76.95 mm

and yes its possible to use the pistons you have but imho opinion easier just to buy new for the job as you say youve waited 10yrs do it properly

although i will say is better for n/a if you bore it to +1.0 which if memory working ok gives you a capacity of 2037cc


26 inlet and 25 exhaust for the ports is a good base to work from too

nath.clarke

I spent 10 years because wife always had a better way of spending my money apparently! Now I am in a position to spend money on car! (at last!)

Thanks for the bore- stroke info! will be useful!

Have you heard of people using longer diesel conrods in this aplication to move the pistons up the bore, and then skim the piston and head for n/a use?

If not, any idea how long the 1800 d conrod is? Is this just a bad Idea and I should stop thinking about it? I red about it in Classic ford, and its made my brain itch!

jp indy3

my mate has just finished his n/a cosworth,i think he spent 6000 or 8000 grand,the head work cost the most,you really do have to spend it on the head otherwise its just a waste of time.make sure you take it to someone you know has projuced good yb n/a heads as it will be easy to get riped off.id go to ht racing.

robrs2

As above with the price. The N/A cossie is a money pit.

You need 1.6 diesel rods not the 1.8 and they are no longer available.

nath.clarke

I found a book on how to port the yb head. I have access to a machine shop. I was going to do it myself! Apparantly as long as I don't go down more than 2mm on the exhaust ports at the bend Its all good!

Anyone done this work themselves, anyone got good results!

Plan with bottom end.

Pinto crank, because its lighter big end ground to suit -> 1800 diesel conrods, width machined to suit, Should give extra 3mm up the bore. Will be able to skim this off piston crowns, machine in valve cuts. Am working out compression ratio (nearly done 3d model to help calculate). Any obvious problems, or have I found an easy way of making a high reving n/a cossy?

t4 and greys

iTrader: (5)

personally i would be using an all steel bottom end
why the reason for the pinto crank???
and what are you hoping to rev to in rpm???
to make the power it has to be strong and be able to rev well ,along with a good ported head
just cant see it happening personally with a std pinto crank and non steel rods

nath.clarke

This confuses me. Classic for says use 1800 diesel rods which are in abundance. Tuning pinto and cosworth book says 1600 diesel. Whats the difference? Does anyone know so as I don't have to buy a book on these engines? does the 1800 turbo have a different crank?

nath.clarke

I am thinking 8500 rpm. Aparently thats what a pinto crank will take. As this is according to the book, has anyone actually destroyed one? Is this a known week point?

I am thinking Pinto crank because it will need to be offset ground, if I get it wrong, oops Ł20! First one comes fre with 205 block. The pinto crank is also lighter, I am led to believe, than the cosworth equivalent. Lighter rotating masses = gains revs better.

Anyone out there got a spare 1600 and/or 1800 diesel conrod/s I can buy/borrow. I am modeling the engine on 3d cad system before I cut any metal, and need these parts soon as a muse! Once model is done I will make it available as a wicked screensaver!

robrs2

Simple, the 1.8 rods don't fit

rallyesport04

have a chat with w.p.e wacky performance engines in croydon they are pro's when it comes to n/a cossies i think to date he still holds a record of some kind in a mk1 escort cossie powered

nath.clarke

Sorry to keep asking, but...... I have just recieved the haynes manual on the 1.6 and 1.8 diesel enine. I also have the Hamill book on the pino/cosworth engine. The dimensions (crank length, small end, big end) appear to be the same as the 1.6.

As I have never had the conrods out of either diesel to compare, or tried this mod, could you tell me what stops them from fitting? which dimension makes them incompatable?

I have taken the advice on the crank, do job properly and think cossy crank is the way.

I apreciate your help

nath.clarke

1.8 and 1.6 dimensions appear to be the same. Pestered my local ford dealer, and they have different part numbers. If anyone knows the differance, please let me know! I have sourced the 1.6 rods but they cost more than the cheapest 1.8s I've been offered.