ausmini :: View topic - Henry power boost!

Louis,

You've got wide collet valves there -- before you do anything, measure them and make sure they're standard size, and someone hasn't gone putting bigger inlet valves into the exhaust. Wide collet valves in non-standard sizes are rocking horse.

Or, just pack it up and send to GR. :wink:

re bigger valves, the easiest solution GR and I have both found is use Morris 1100S valves and turn them down to what you want.
Don't go too big on a 998. 32mm inlet /27mm exhaust is plenty.
Note these valves are 2mm longer (approx), you will need to put a 12mm flat washer under the springs to maintain tension, and pack the rocker posts up about the same amount to maintain geometry.

You will need to buy 16 new radius groove valve collets, but you can keep the top caps (on a roady motor).

Or, just pack it up and send to GR. :wink:

<edit> wide collets have a wide groove, they were superseded by radius collets and valves about 1975.

<edit> i should mention that the head will come without any valve or spring, is this make it easier

henry the mini wrote:

<edit> i should mention that the head will come without any valve or spring, is this make it easier

eeek!! from what I just read from Doc and SGC, I'd say it make it damn near impossible.... or very expensive at the least. Talk to some gurus in person before you pay for the head.

Getting GR to sort it out would be the bes idea, but it won't be cheap - buying the 1100S valves, then machining them, along with getting the seats etc. done in the head. Don't know if I'd like to guess, but I reckon you'd easily be looking at $600. I pay around $250 for a basic head recondition on a stock head... buying valves on top of that, machining them, and the rest won't be free :S

Author:	henry the mini [ Fri Mar 14, 2008 11:23 am ]
Post subject:	Henry power boost!
Just got myself a 12g295 head to go on my car. I intended this to be a project i do for learning. My knowledge is minimal, very minimal. So i will need all the help i can get along the way. First, my engine is a 99H E22, can anyone tell me exactly what it is? as i understand it, it is (dished pistons with press fit pin) is this correct and what does it means? Here is the head. What is the first thing to do? Caustic bath and bead blasted??? Crack tested? What modification this will need to fit the engine, and who in Melbourne has got knowledge to do any machine work on a mini head? Also, how much can i expect to pay for the machining and what modification will be worth it? Sory i have so many question Hope you can all help me...

Author:	gafmo [ Fri Mar 14, 2008 11:27 am ]
Post subject:
i wouldnt bead blast it just the bath and defantly crack test it

Author:	simon k [ Fri Mar 14, 2008 12:10 pm ]
Post subject:
and as the doc will tell you, it needs to be planed as those heads have a large combustion chamber, and you'll end up with very little compression... making for less grunt than you have now get Ballistic or someone to recommend a head reconditioner who will take care of whatever work needs to be done, including cleaning and testing and fitting new guides and exhaust seats and whatnot

Author:	1018cc [ Fri Mar 14, 2008 1:01 pm ]
Post subject:
Get about 0.060" taken off of it to bring the compression up a bit. That way it won't ping but it won't give you compression below 8:1 (I read a thing on here a while back that so many thou was equal to 1cc.......dunno where though, can't find it). If you start to go more than that I have heard that there isn't enough metal in place to hold the head gasket there and they blow more often (e.g. 0.080"+). My head has had 0.055" taken off of it. It doesn't worry me if my car is at around stock compression. When I went away last time I was getting close to running out of fuel, the best I could find was 95 octane and it still ran fine. Even if you keep compression around the same it is now it'll still add power, just not quite as much if your C/R was up around 10.5:1. Louis, I'm pretty sure that one was just about stock (had 0.003" taken off). Getting some metal taken off will also make sure that it is nice & flat for the H/G.

Author:	sgc [ Fri Mar 14, 2008 3:15 pm ]
Post subject:
Louis, You've got wide collet valves there -- before you do anything, measure them and make sure they're standard size, and someone hasn't gone putting bigger inlet valves into the exhaust. Wide collet valves in non-standard sizes are rocking horse. An otherwise excellent '295 head I picked up last year had this problem, and replacing the valves turned out to be impossible without having custom valves machined, an expensive exercise. As for compression, we took 60 thou off the head to fit to a 99H engine, we calculated it to be something like 8.7:1 I think. Good luck with it, the '295 is a good head for a revvy 998... if you can find a good one

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Author:	Dylans Clubby [ Fri Mar 14, 2008 3:25 pm ]
Post subject:
north geelong engine reconditioners then have a chat to scott ballistic. louis, you and me will ahve to go for a drive and not invite the others, with our "little engine" minis. i'll even bring the CB radios

Author:	henry the mini [ Fri Mar 14, 2008 3:47 pm ]
Post subject:
sgc wrote: Louis, You've got wide collet valves there -- before you do anything, measure them and make sure they're standard size, and someone hasn't gone putting bigger inlet valves into the exhaust. Wide collet valves in non-standard sizes are rocking horse. What do you mean, not shure i understand . Is it a big problem as it's not too late to pull out

Author:	1018cc [ Fri Mar 14, 2008 3:52 pm ]
Post subject:
Wide collets? I know this is a dumb question but how do you tell?

Author:	drmini in aust [ Fri Mar 14, 2008 3:53 pm ]
Post subject:
re bigger valves, the easiest solution GR and I have both found is use Morris 1100S valves and turn them down to what you want. Don't go too big on a 998. 32mm inlet /27mm exhaust is plenty. Note these valves are 2mm longer (approx), you will need to put a 12mm flat washer under the springs to maintain tension, and pack the rocker posts up about the same amount to maintain geometry. You will need to buy 16 new radius groove valve collets, but you can keep the top caps (on a roady motor). Or, just pack it up and send to GR. <edit> wide collets have a wide groove, they were superseded by radius collets and valves about 1975.

Author:	Dylans Clubby [ Fri Mar 14, 2008 3:53 pm ]
Post subject:
bigger valves mean more fuel/air can get in, and more exhaust can get out which means it will go harder but the downside of that is you will use more fuel, and as stated above the valves may be hard to get, or expensive...

Author:	henry the mini [ Fri Mar 14, 2008 4:02 pm ]
Post subject:
drmini in aust wrote: re bigger valves, the easiest solution GR and I have both found is use Morris 1100S valves and turn them down to what you want. Don't go too big on a 998. 32mm inlet /27mm exhaust is plenty. Note these valves are 2mm longer (approx), you will need to put a 12mm flat washer under the springs to maintain tension, and pack the rocker posts up about the same amount to maintain geometry. You will need to buy 16 new radius groove valve collets, but you can keep the top caps (on a roady motor). Or, just pack it up and send to GR. <edit> wide collets have a wide groove, they were superseded by radius collets and valves about 1975. Are we talking big and expensive job here or simple stuff. Would it turn out easier to get a 202 and have it modified. I am so confused <edit> i should mention that the head will come without any valve or spring, is this make it easier

Author:	simon k [ Fri Mar 14, 2008 8:52 pm ]
Post subject:
henry the mini wrote: <edit> i should mention that the head will come without any valve or spring, is this make it easier eeek!! from what I just read from Doc and SGC, I'd say it make it damn near impossible.... or very expensive at the least. Talk to some gurus in person before you pay for the head. Getting GR to sort it out would be the bes idea, but it won't be cheap - buying the 1100S valves, then machining them, along with getting the seats etc. done in the head. Don't know if I'd like to guess, but I reckon you'd easily be looking at $600. I pay around $250 for a basic head recondition on a stock head... buying valves on top of that, machining them, and the rest won't be free :S

Author:	spraycanmansam [ Fri Mar 14, 2008 10:06 pm ]
Post subject:
I got my 295 dipped, bead blasted and crack tested for $50 to give you an idea of price. Came up beautiful! It's like brand new

Author:	henry the mini [ Fri Mar 14, 2008 10:11 pm ]
Post subject:
simon k wrote: henry the mini wrote: <edit> i should mention that the head will come without any valve or spring, is this make it easier eeek!! from what I just read from Doc and SGC, I'd say it make it damn near impossible.... or very expensive at the least. Talk to some gurus in person before you pay for the head. Getting GR to sort it out would be the bes idea, but it won't be cheap - buying the 1100S valves, then machining them, along with getting the seats etc. done in the head. Don't know if I'd like to guess, but I reckon you'd easily be looking at $600. I pay around $250 for a basic head recondition on a stock head... buying valves on top of that, machining them, and the rest won't be free :S Thanks Simon and all the other. I pulled out, too much unknown. Very hard to buy stuff from the net really

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