200 replies to this topic

[FLD]

Just an idea.... why not get the chamber, valves and ports ceramic coated to stop carbon sticking and to help keep the heat in the charge. Works quite well on BBC and SBC cars. Camcoat do it at a reasonable price. HTH?

[Muncher]

Vocky, how much does a sand cast head cost and what sort of gains can be had from having a ported head? If it's not too much and the gains are good I may get one to have a play with, mainly because it looks quite satisfying doing it!

[vocky]

the 'saab/LSJ/sandcast' heads are quite hard to find, but not that expensive to buy also not really required unless you are sc or high compression na the z22se ports are quite restrictive, the sandcast ports are better but still need improvement. to give you an idea of how small the exhaust ports are I increase the outlet 5mm (2.5mm all round), so thats quite an increase in area (standard = 37x22 mm, ported = 42x27 mm) the inlets are just a poor shape, some careful adjustment improves the flowrate As for bhp increases, that depends on the engine spec, a standard engine fitted with a stage 1 head (standard valves) should give 10 bhp, a fully sorted engine with a stage 3 head (+1mm valves) should give 30 bhp I have seen the 2.2 ported heads advertised as between 10 and 50 bhp gains, I would love to see the engine which gave a 50 bhp increase

[vocky]

finished the first pair of exhaust ports, so just 3 more cylinders to go



you can see the difference I make to the exhaust ports, just use the gasket as a template and scribe around the port, then remove the excess material ensuring you keep the sides flat as you correct the port shape

I haven't seen any uk 'off the shelf' ported heads which have had this done

[Muncher]

What's the difference between a stage1 head and a stage 3 head? I'm going stage 1 supercharged in a couple of weeks I was thinking of putting a ported head on when I go for the smaller pullery and chargecooler. If the stage 2 charger gives say 245bhp, wouldn't having a ported head give me so much more that I'm beyond the limit of the standard bottom end? When you say they're cheap, how cheap are we talking? I guess you just use a Dremel or are there any special tools to do it?

Edited by Muncher, 07 September 2008 - 01:26 PM.

[vocky]

In general they are classified;

stage 1 has the ports cleaned up and keeps standard valves

stage 2 has larger ports and keeps standard valves or cleaned up ports and bigger valves

stage 3 has larger ports and bigger valves

power gains I stated are for NA engines only, forced induction will react differently to improved engine flowrates, you may not see such high gains

GM said conrods are known to fail at 285 bhp, Eagle steel rods are a good investment

I use a die-grinder for roughing out and a dremel for finishing

[Winstar]

When you say they're cheap, how cheap are we talking? I guess you just use a Dremel or are there any special tools to do it?

this is the best online guide i've found clicky

[slindborg]

the sandcast heads do have slightly smaller ports than the lost foam ones (unless Matts head was well ported out lol) Just need to get my head pressure tested and it will be out forsale

[Baron Von Scubadaddy]

When you say they're cheap, how cheap are we talking? I guess you just use a Dremel or are there any special tools to do it?

this is the best online guide i've found clicky

when I did a search for this a while back I found this guide
I'm gonna follow this

I've Maxr's old head and will be doing the porting on the
kitchen table over the winter

Edited by Baron Von Scubadaddy, 07 September 2008 - 07:11 PM.

[vocky]

don't forget you need to use carbide burrs and sanding discs not stone grinding wheels

[Muncher]

It's interesting because at what point would you whip out the whole engine and buiild it as a special one like you've done vocky... On a SC engine do you think you'd see 10bhp+ with a stage 1 head? When you put bigger valves in does that require any more serious work that you can't do on the kitchen table? Having never used a die grinder before, how does it differ from a dremel other than you can vary the speed more easily?

Edited by Muncher, 07 September 2008 - 07:53 PM.

[vocky]

I removed my engine to do the balancer delete, fit the eagle rods and a lightened flywheel, so it made sense to take the engine out. conrods can be fitted with the engine in the car, as long as the head is off otherwise I would say you just need to remove the cylinder head. on the z22se site a guy has 260 bhp with a stage 2 sc conversion, but he has schrick cams and a ported head, so they only gave 10 bhp. I think he could get more power if he changed his conrods and had a few other bits done, which would then see more power from the head work, it's just that forced induction isn't restricted by the standard head until stage 3 you need to have the valve seats machined to fit bigger valves, but you could simply fit standard size wasted stem valves instead. you can port a head with just a dremel, I also have a die-grinder which makes removing excess material very easy

[Muncher]

Is it the rods which limit the rpm on the standard 2.2? Given that the SC power delivery seems to be going up and up until you hit the rev limit, removing that bottleneck would be a good idea? I suppose if you have the head off to do that it would be rude not to swap it for a ported one...

[Baron Von Scubadaddy]

This is starting to sound more complex than I thought (as usual ) I was just going to get a dremel remove the rough bits make it look like vocky's pictures put the bits in that are missing like vales and stuff ( yes I know shag all about engines ) give it to my local garage (who now dose all my work) along with the new TB and inlet manifold and Roberts your Dad's brother . Please say there is no more to it than that

Edited by Baron Von Scubadaddy, 07 September 2008 - 08:28 PM.

[vocky]

Is it the rods which limit the rpm on the standard 2.2? Given that the SC power delivery seems to be going up and up until you hit the rev limit, removing that bottleneck would be a good idea? I suppose if you have the head off to do that it would be rude not to swap it for a ported one...

I may be totally wrong, but I believe that the sc conversions are kept down to 250 bhp due to the rod issue.

certainly it makes sense to keep the power to a level which the bottom end can cope with.

if you fitted steel rods then I'm sure more power could be found and a ported head would certainly help with a stage 3 sc conversion.

in the states many are getting 350 bhp at the flywheel (from their sc engines), they have all fitted a ported head to reach that power level.

This is starting to sound more complex than I thought (as usual ) I was just going to get a dremel remove the rough bits make it look like vocky's pictures
put the bits in that are missing like valves and stuff ( yes I know shag all about engines )
give it to my local garage (who now dose all my work) along with the new TB and inlet manifold
and Roberts your Dad's brother .

Please say there is no more to it than that

you make it sound so easy

if you buy some standard size wasted stem valves you need no maching work, just port the head and after it's been cleaned reassemble the head

nothing hard about that, just don't expect to port a head in a day, I've spent two weeks on it and will spend another two weeks to finish it, you get bored after a while, so stop and do some more another day

[slindborg]

I may be totally wrong, but I believe that the sc conversions are kept down to 250 bhp due to the rod issue.

which technically the rods dont see...... as yeah you get 250bhp at the fly, but what about the 30orso BHP needed to spin up the S/C in the first place, so true crank power is more like 280 bhp :S


but yeah, power wrecks the STD rods (although im sure revving it to 8K with under 250bhp would pose problems too )

[Muncher]

vocky, the LSJ head is the same as on the Vectra C 2.0 turbo isn't it? And on one of the saabs so surely it's relatively easy to get hold of from a scrap yard for a few quid? How much did you pay for your rods?

[vocky]

the sandcast head can be found on 2003> saab 93 turbo and the 2003> vectra 2.0 turbo

Eagle conrods are $350 + shipping + any duty from all ecotec dot com

they will ship to europe

[Muncher]

Great thanks vocky, useful as ever! What could you consider to be a good price for the sand cast head? If I'm ordering something from allecotec are there any other bits I'd be wanting to get from them such as valves/bolts?

[Jameshs]

Changing the subject slightly but what are the parts like from that allecotec place? Looking at the cams really