......... Is what has been taking up the vast majority of our time just lately.
One 8v and three 16v integrale heads, one Peugeot/Citroen 8v 1.6, one Toyota 1.8 16v and a Toyota 2ltr 16v turbo have either gone or are in the process of being improved.
The Toyota 2ltr head is going on a very high powered (circa 900bhp) engine powering a road legal drag racing MR2. I've had this head in the shop before when it was used on a lower spec engine, it got high lift cams, under-bucket shims and only very light porting work. The head needs relieving around where the cam lobes spin as there isn't enough clearance for 11+mm lift and the OE top mounted shims are known for jumping out to say hello at high RPMs with equally high lift cams.
The head flows well (read: They are totally OTT and fecking huge*) from a max CFM perspective straight out of the box, hence it only needing light shaping of the ports. Infact you could (as I proved) fill back up a large amount of these inlets and re-do them picking up both velocity and CFM on the way, but as usual it's down to (lack of) budget to go down this route.
Last time out the engine saw a rather frightening (in a mid engined RWD car) 740bhp before the block cracked as they are well known for doing so at this power level.
*The reason for this is the factory fitted, but now redundant 'T-VIS' system which blocks off one of the 8 separate inlet manifold tracts.
Now you would of thought the owner Dougy would have been quite relieved for this monster to die (I think his wife was), but no, he's back for more with a stronger 2.2 block and crank! We've also found out that there are 2 different generations of this head and the port shape and angle changed quite a bit, some careful scrutinising and measuring has been going on to decide which way to go, early head has bigger taller ports, but more downdraft, later has smaller fatter D shaped ports, but less down draft.....
The suitable head will then receive larger valves with seat and throat work to suit.
When it's done I won't be going out for a drive in it.
One 16v Fiat/Lancia head went to Bastiaan in the Netherlands for his Punto 2ltr conversion, another is going to the U.S. for Jorge on the top of a 2.2ltr engine we are building for him and the final staying in the UK to replace one in an integrale badly damaged by cambelt failure/slippage. Remember to keep your eye on your belts fellas, genuine Sodium filled exhaust valves are now around £80 each. Times that by 8 and you've got what is only the start of some hefty repair bill.
Apart from the integrale heads my favourite from the above is the Saxo 8v VTR head, it responds so well when you re-shape it in all the right places that it is a joy to work on, check out the graph below, this little engine is going to fly, good in valve flow all the way up the scale from low lifts to high:
In these pics one port and one combustion chamber have been given the treatment in comparison to the one next to it, initially and visually the difference is minimal, as you can see no cowboy 'Opening out' 'hogging out' or stupid polishing of the ports has been going on, the outward differences are very subtle, but the figures aren't.
Up on the lift earlier in the year were too pretty rusty 16vs, obviously no rare sight, but both owners and us happy to see them given some more life. We don't plate over rust like many do:
It's cut out to as far back as discussed with the customer and replaced with new metal, fully welded, painted and wax injected from behind.
I've also been working with a local CNC router genius on the Stage 2 gearbox strengthening so we can offer that as a service too. What we are finding on strip down of the gearbox is that the holes which hold the bearings for the two shafts of gears have gone oval, not just a bit, but quite a lot. Under power these are pushed further apart until the mesh on the gears is reduced and teeth begin to ping off:
You can see below how both the gearbox and the spectacle plate we are making are mounted side by side so the machine cuts one after the other for a perfect fit.
1st example of a new design of ex-manifold:
Despite instructions that it be made from smooth flowing mandrel bends it came like that so I put some EGT sensors in it, had it ceramic coated and mounted it on Project Sausage, at least we can use it as a test piece as PS had practically blown my old Evocars manifold to bits.
And finally.......
To finish off this chapter is a nice way someone has found to get a car to pass an MOT test when it fails on lack of rear braking effort. Strip down the bias valve, linkage, free it off and re-assemble? Nah, just throw money at it.
And hope it sticks in the right place!
