4.0 OHV into 4.0 24v COSWORTH

As the topic. It's based upon a 93:ish 4.0 bottom end and the rest of the bits are from a 2.9i 24v BOB cosworth. Just missing a few bits to be able to put it all togehter. But here are a few old pics from how a few bits fit together.

 

[410Fortune]

more details please

Whats it going in? How much power did it end up making? Is the 4.0L block left stock?

Looks *****in

 

[CodePoet]

more details please

Whats it going in? How much power did it end up making? Is the 4.0L block left stock?

Looks *****in

What he said! Got a dyno sheet?

 

[Tobbe]

It's not finished yet. I would guess it will be around 300bhp with theese heads and stock cosworth parts, a 2.9 cosworth bored and stroked into 3.7 yields 278bhp and 407Nm with everything else stock. The bottom end is still stock but I am looking for other stuff for it, but I got a limited budges so I am open to suggestion to what to use in it. I am going to use the engine in a car known in Europe as Ford Sierra 2.9, looks just like the sierra cosworth. The engine management will be the low budget megasquirt and edis, but it will be mapped on a dyno so it will be done correct.

The way of the oilpump rotation had to be fixet.
The block needed a bit of welding so the chain guide would line up. Also the timing cover needed some work, and also a few guides did too.
Custom headgaskets are on order, they are part of the solution to cover up the oil returnes in the V.
And a few more bits have been done.

 

[Turdle]

Holy--what the--
wow--I am impressed now!! This is way off the wall!

 

[Tobbe]

I heard from some bloke that it should be possible to bore the block into 4.030 and use chevy 350 pistons and 6" rods, with some smaller mods. Any one know if this is possible? Also one thing to know is that the volume in the head is only 33cc. So it must be possible to machine down the piston crowns a bit.... Maybe there are some low compressions ones that will fit without any hazzle? I got no experience what so ever of chevy stuff. But I know that they are cheap.

 

[410Fortune]

yikes, I am sure its possible, but the OHV 4.0L is already a bored and stroked block the walls can get quite thin when they are bored.
There are plenty of go fast goodies available for your V6 these days including engine internals. Because the SOHC 4.0L was used in the late model Mustangs the aftermarket for these engines has finally gotten a boost. Try a search on this forum to find the builders/4.0L V6 experts and shops that are out there.


The 4.0L OHV bottom end is known for its durability.

Have heard of people using a mix match of SOHC and OHV parts together to make some wild engines, one of them here in Colorado runs on race gas only because his SOHC pistons in a OHV block has like 15:1 compression.


Did you convert the 4.0L oil pump drive using 2.9L parts?

 

[Tobbe]

Did fail on machining a own helicalgear so the 2.9 stuff had to be modded with bigger journals, and also the distributor dummy plug is used, ofcourse there are some moddes to the lock washer aswell. Got a spare saft from a mate in UK, did also get a few other parts so I still can put the 2.9 together.

The pistons I can sort out, but the connecting rods... By the way, is there any web shop where you can get stock piston rings for the 4.0 in US? Over here they cost more then 300$ for a set.

This home made piston for the 2.9 is a close copy of the stock one but with a bit lower compression. Valve cuts out have been added, they were done in another machine so that's why the aren't present in the pictures. Maybe a nicer one should do for the 4.0.

 

[EMG7895]

Nice work, I'm not familiar with the cossworth so I cant help very much. But I can tell you that you should be safe leaving the bottom end alone if you wanted. You have to try pretty hard to kill the bottom end in the 4.0, I have seen one with over 200,000 hard mile on it taken apart and it still was within spec.

 

[jah81592]

Those heads look similar to the 32V 4.6L(ports,valvetrain).

 

[Fredness]

What are the chances of getting these heads/intake in the US?

 

[Minivek]

saw some heads on ebay just type cosworth head, but they're in england of course. Really interesting setup he's got there. Hope we'll see a finished product!!

 

[dkchrist]

subscribing

 

[Stic-o]

Very Nice My dad has a '69 Cortina GT MKII we've talked about putting a 2.8 or 4.0 into. This would be pretty cool in it too though

 

[Heavymentill]

http://agnes.goams.com/ford/

 

[Tobbe]

http://agnes.goams.com/ford/

Wonder how it turned out for him, if he ever finished the engine.

There's a big differ between his and mine engine, his was BOA based and my is BOB based, meaning different heads, chaindrive and inlet. The only boa stuff I am going to try to use is the thermostat housing, if possible.

Besides the 2.9 BOB gives 207 bhp and the BOA 195bhp, so for 2 reasons it is better to go with the BOB, 1# more power 2# it is easier.

And an other big differ is that I got a 2year old CNC lathe with driven tools, cad cam, bet he does not

 

[jah81592]

What are the chances of getting these heads/intake in the US?

That would be cool! I was super excited till I got my head out of my rear and realized that they wouldn't work with the SOHC.Darnit!

 

[Fredness]

Well, I'm not up on SOHC/OHV block differences, but why wouldn't it work?

It's my understanding that the SOHC oil pan bolts to the OHV, so worst case you use an OHV block, SOHC oil pan/girdle and the Cossie DOHC heads and intake, right? Or are you talking about the chain difference where the Cossie uses two long chains and we use 3 shorter chains off the "Jack Shaft"? I think that actually works to our adavantage! We could modify the internals to use the Cossie 2 chain system and not have to fab/modify our timing cover... maybe...

Other than not being able to do the DOHC head swap in an afternoon with the 4.0L SOHC engine still in the mounts of your Explorer, What's wrong with that?

I think I'm missing something on the oil pump drive though. The cam has an opposite direction drive for the oil pump, OK, I got that. So what? Is there a reason the lobes can't be ground off the 4.0L OHV cam and use the 4.0L OHV factory oil pump/drive? I think the issue here is vs. , with Tobbe's inability to access to parts.

Tobbe: What timing cover are you using and does it bolt up? There looks to be a CnC (2mm?) adapter beween the timing cover and the heads, can you confirm/elaborate? What oil pump are you using (Cossie, I assume) and why? Thanks!

 

[Tobbe]

Actually, I have heard of a SOCH based engine being built in Norway, it uses 2lhs heads. More I don't know, got this info from a mate in UK. And there is also a guy in Belgium that have plans on a OHV based one, but I haven't heard any more from him. I tried to offer him some help but......

Have a rethink of the oil pump drive. With the 24v chain drive the 4.0 camshaft will rotate the opposite way that it would with the 4.0 chain drive. Meaning the oilpump would rotate the wrong way. This must be sorted, and the easy way to do it is to use the cosworth jack shaft, still the cosworth gear doesn't look to good on the 4.0 cam so you got a problem there aswell, it's not even close to line up to the rest of the chain drive.
I still have the 4.0 pump in the bottom end, and I didn't really plan on changing it for the cosworth one either.

I am using the timing cover from the cosworth and it lines up pretty good. Yep there are spacers. The 4.0 block is 20.1-20.2 mm higher then the 2.9. The gap you see will have a gasket later on, and in the pictures the heads are a bit higher then they will be later on when the real head gasket is assembled.

 

[Fredness]

Now it make perfect sense, I should have figured that from the "missing chain". I think, If I were to be able to get the heads, I'd go with the SOHC style and the 3 short chains.

Man, That is some great work! Thanks for the reply...