This is my van..it's a bit different to most!!!
I did this head conversion with the block in the van...which involved some creative solutions to problems encounted.
The block is a 2.5ltr,balance shafts removed,300K klm old bores that have been honed,new pistons and rod bearings fitted 20K klm's earlier (also done with the block in the van),original main's etc....
I Greased up the top of the bores,sliped a large O ring that fit perfect into each cylinder,taped off the cylinders,rolled the crank around until the pistons pushed the O rings against the tape,then ran a razor blade around the outer edge of the orings,effectively sealing the cylinders from junk while the rest of the block mods are done.
I used the old Stratus 2.4ltr mls headgasket as a template for drilling the new cylinder head locating dowels.They are now in the corners rather than in the centre of each end,as with the 8 valve sohc head.The headgasket was bolted down,and guided the drill bit perfectly.I used a drill bit a hair smaller than the dowel and reamed them slightly with a die grinder so the dowels were a tight fit (couldn't find the exact size drill bit).
I used rubber grommets with small machine srews tightend through the centres,covered them in grease,then slide them down the oil feed,oil return,and crankcase pressure eq. port,sealing the bottom end from swarf.Then I tapped the holes for pipe plugs,running them deeper than the headgasket surface.I had to increase the diameter of the oil drain back holes with a die-grinder to get the tap to start properly,and then took my time running the pipe tap in and out until the pipe plugs would sit below the deck surface,and still be tight.Once the holes were tapped,I used a shop vac and brake wash to clean out the swarf as good as possible,then reached into each hole with needle nose pliers,grabing the threaded end of the screws,and pulled the plugs out.They worked really well! I then cleaned up the holes and wound the pipe plugs into the block so they sat below the deck surface,then used JB Weld to fill the heads and also fill the original dowel holes.I let it set-up (had to use clear parcel tap over the JB to stop it running),and then with a 3M pad in my trusty die grinder I carefully ground the excess JB off.On the front of the block,I have taped and fitted a barb for crankcase pressure relief.It is into the original port cast into the block,and then I reinforced the fitting with JB Weld as the casting is thin here and there isn't alot of threads.If you are having trouble with the JB Weld running down hill while it sets,again,use a piece of clear parcel tape to hold it in place,then when it has set,the tape peels off perfectly! I also had to align some of the coolant ports,and drill an extra hole into the deck of the block on the exhaust side of #4 cyl,to match up with the DOHC headgasket.After all this,I used a dead flat heavy peice of angle Iron wraped in emery paper and WD40,moved in a circular motion back and forth along the deck,to clean it back smooth.I checked it all over with a straight edge afterwards,and it came up perfect to my eye,and feeler gauges!
With the head,I seated the valves by hand,cleaned all the combustion chambers of casting/maching edges,cleaned up the intake and exhaust ports.I tapped and pluged the oil drains,and pressure eq. port from below,also using JB Weld to help seal them,then used the same surfacing technique that I used for the block.In the drivers side of head,I drilled and tapped beside a large freeze plug for the coolant sensor that the ECU (SMEC) uses.You also have to allow a place for the sesor that drives the temp gauge too.I put it at the thermostat housing on the intake manifold.I also removed the plugs in the end of the oil gallerys for the lash adjusters (my head had the freeze plug style press fit plugs),and now feed oil to the head from the oil manifold on the front of the block via a hose,into the inlet valve gallery.This fitting is a T with the feed into the head restricted to 1/8th drill bit,and the other end continuing off to the turbo.The T fitting has been tapped internally to 1/8 pipe thread,and has a drilled plug screwd into it.I did this so I could experiment with restrictor hole sizes.The tapped exhaust lash adjuster gallery is used for feeding a oil pressure gauge and low oil pressure sender.It idles hot at 20psi.The plugs at the opposite end of the head really need to be ground back too,to alow the new cam gears to sit closer to the head so the timing belt lines up properly.
Sorry,no pictures of this stuff...
I fitted large #12an fittings to the head for oil return to the pan,and reinforced them with JB weld,as again the casting is thin and there isn't many threads here.Had to allow enough room for the exhaust manifold,and to clear the p/steering pump and bracket once assembled.I removed the oil pan and welded some cast steel female pipe thread fittings to it just below the gasket/mounting surface,then turned in 90* #12 fittings being careful to allow room for the passenger side axle.I then made some crimped hoses to suit,at work. If I was to do this swap again,I would look at using SAE flare fittings and bending/flaring some tubing to form the oil feeds and return lines.I think with some practice with a tube bender etc,the lines could be made very neat and be cheaper to build.
I had to tap and plug the oil feed port beneath the last intake cam cap at #4 cylinder,so oil pressure didn't flow back down the port next to it ,and against the head gasket,possibly causing a leak.The cam cap at the belt end of the head that retains both cams,has oil bleed ports which I sealed off with JB Weld.They're not needed,and it reduces the amount of excess oil trying to flow down the oil return hoses.I tapped and plugged the EGR port also.I don't use the barbs on the valve cover for the PCV and breather (they are blocked off),instead I have them running from the block,trying to encourage the oil to drain back down the new returns.
If you are using a stock distributor,in the stock location,with stock style straight ends on the spark plug leads,you will have to grind some of the head casting back so the distributor has a good range of adjustment and you have a chance at getting the cap on and off.....OR,do what some have done,and use 90* ends on the plug leads and save some work (not sure what these 90*'s came from).The distributor is a BASTARD to get at with the stock Stratus intake manifold,so be warned!!!
Sorry,no good pictures here either..
As mentioned above,I have used the stock Stratus intake and throttle body for this budget swap.To use it,I junked the cruise control,and used a neon throttle cable as the van's is too short.The neon cable is a bit too long but works fine.
The cam gears I used are modified Honda Accord a20a1 sohc 12v'89 models.The particular gears I used seem to be rare,as I have tried to find more exactly the same,but 9 out of 10 times find gears with a different off-set.I can't find EXACTLY the model of the car that will have the right ones,or the part#..frustrating.Most people are using custom made adjustable gears,but they are more money than I could afford.With the Honda gears,I had to correct the offset to get them closer to the head,and to use a small bushing 1mm thick to reduce the inside diameter to suit the cam.The locating dowel slot had to be elongated a little,and the timming marks work almost perfect with the Stratus cams.These gears are close to not woking for belt alignment,as there is only so much you can machine off them before they are too thin where they mount to the cams.The ones in the pctures need more off them than shown,although I am running them at the moment and the belt runs slightly off the inside of them.They were cheap,but could get expensive if they fail!!!
The exhaust manifold was made from 1 1/2" cast steel weldable elbows and T's,and 3/8 flange cut with a torch.I ovalized the elbows and T's in the press to match the shape of the exhaust ports,cut the flange and tapped it for both Chrysler and regular T3 Garret turbo patterns.Works great,no cracks or leaks so far.
The turbo I am currently using is built from Chrysler .48a/r turbine and 2 1/2" swingvalve,and Ford .60 a/r compressor.It is way to small for this engine,but it's what I could build with what I had.I have since come across a Holset hy35 and a hx35 turbo,so the little one won't be on there much longer!As you can see,the stock turbine housings are bad for cracking due to the rediculous back pressure and heat they generate..The turbo is a tight squeeze against the firewall,had to push the wall in a little..
I have swaped the little garret for a Holset hy35 from a Cummins powered Dodge Ram.The difference in power is amazing...It builds boost very fast,and starts only about 500-800rpm higher,so around 2500-3000rpm.It pulls hard all the way to 6000rpm,very impressive for the money they cost.I had to build an outlet for the turbine,and bracket to mount the wastegate actuator.
From left to right:
Holset hy35,Garret .60 Ford compressor on a Chrysler .48 tubine,Stock Chrysler Garret from a 2.2T car,stock minivan Mitsubishi turbo.
A new exhaust down pipe had to be built to suit the holset turbo,3".
I also built an intercooler for the van.I had a used core from a motorcoach that I cut down to L:34"xH:20"xW:2.25",and made the end tanks by ovalizing 3"tube and cutting it into the needed angles to try and distribute even flow through the core.The ends took alot of work as there was no room between the headlights,radiator or battery....and I had never TIG welded before.The welding was very difficult,but with help from a friend Chad,we got it together,without leaks,and reasonable looking welds.The insides of the tanks were ground back and smoothed out completely before being welded to the core.I haven't measured temps accross it,but after a hard run it is stone cold on it's outlet tank,with the inlet fairly warm.Great frustration,and great experience building this piece.
The van really hauls ass now!At 12psi it makes waaaay more power and torque than the old non intercooled little turbo set-up at 15psi.I haven't measured it at a dyno,maybe later in the year,if it continues to hang together!!
Thanks for looking!!