Check out my "Bath-Tub" chambers

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Wow it must have been powerfull... seems it bent space-time enough to give you two Friday arvo's in a week

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"Life is not like a box of chocolates... it's more like a jar of jalapenos. Whatever you do today, may burn your arse tomorrow."

Hey they look just like mine!
<edit> here's a pic from a while back, yes it looks better now..
Valves are 35.6mm inlets and 31mm exhausts, all S/S ones.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

hee hee,,,my cyl head designs aren`t patented yet, so i spose it`s ok to be copied

& yeah, ok,,,2 fridays in one week, sounds preety good to me ,,,should have read the "thursday arv" anyways ,,,i must admit that i hit all those dynos in the same week to have as much climate the same for each run,,,i was just sickend by the amount of people who came to my shop declaring so much bloody HP from their engines when even my shitty old stocker was quicker, so my 1510 was the base test to see which dynos around brisbane gave the Lowest figures & so far from all that running around it ended up at Bob Romanos gave the lowest figures ...& as it so happens, he moved his whole shop just down the road from me now

we don`t have him tune anything for us as even when he did try to tune mine he didn`t gain anything, so we just use him to run them up only if the customer wants a piece of paper printed out showing the mixture ,HP & torque results , easy-peasy

it`s all gotta go together as a "Package"

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Hey guys whats the idea with the removal of the 'beak' in the chamber ? Are they for use with turbo's ?
The 'beak' should be left in on NA engines as this creates 'Swirl' in the chamber which in turn promotes better combustion.

Smiffy, if you look at my head, i`ve actually left a heap of the beak there, but, that head is actually 33cc chambers so , well,,,er,,,ar,,,you gotta take it out of where ever you can when you need em that big ey? check out the spark plug side of the head & compare to std one mini heads don`t really have a lot of meat to play with under the beak, they can get very thin there & also right next to the exh valve between it & the spark plug too, got to be carefull.

I`m a big believer in leaving some of the beak there no matter what the use (N/A or force fed) i also try to creat a path for the "sheep though a gate" (one of my dad`s old cyl head working quotes ) which helps direct the gases away from just cutting straight across & into the exhaust instead of actually filling the chamber nicely.

There`s all sorts of "tricks of the trade" when doing head work & you not only need to know how they all work & why, but also which ones actually do work on mini heads in particular. Some stuff commonly done on other types of cyl heads may not actually do anything (just wasted time) & some others actually detract from performance/efficiency on a minis agricultural cyl head design.

many years of working mini heads (& testing em) is really the only way to know,,,or just pay someone who allready knows

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

I take it with 33cc chambers that you do run forced induction then, not mening to stand on anyones toes or anything. Only asked because I was interested why all the heads had such big chambers ("Bath-Tub" chambers), thought maybe you had really crap petrol which would account for the low hp figures I had seen posted around the site.
Quite funny how things work coz over here, the latest development is taking more metal out of the head around the spark plug area.
ps. was just interested thats all

Smiffy,
Mine (in the last grotty pic above) was used on the street with 1310 Mahle flat top pistons, for years.
The chambers (28cc) were opened out to get the C/R down to 10.4:1 running the then available 95RON fuel.
It's been decked a bit more since- now running great at 10.7:1 on 98RON fuel, with Hypatec 73mm dished pistons.
Hmmm... could probably run it a bit higher now with the 282 cam...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Ahha I see now you all run flat tops

yeah smiffy, my cyl head is for a 1510cc road donk i built about 9 years ago & that particular head had allready had some off the face of it, so needed to open the chambers up to my "bath tub" size to get the comp ratio down low enough for road use with our crap pump fuel. Big donks neen big chambers to keep to a reasonable road suited CR level as i`m sure you know.

& well,,,just take another gork/look at how much meat is gone from around the spark plug area & i ported this head when i was about 18 years old (24 years ago) for my 1415cc race donk & then opened the chambers up like that about 9 years ago to suit the 1510 roady donk

I was just mentioning how thin heads can get under the beak & around & between the exhaust valve & spark plug hole, much more out of my head & it`ll crack, been there & done that many times before so i know where not to go too far my dad had me grind so many small bore cyl heads when i was a kid, just to get practise on the cheaper (dime a dozen) small bore heads compared to just ripping into a 1275 cyl head without much die grinding skill, so when i finally was good enough on the small bore heads, he then let me rip into 1275 cyl heads

& as to relatively low hp figures around here, well,,,i think you`ll find that there`s a number of reasons for that, --->we have a very hot climate, we have crap fuel, we do have tighter dynos (in general) & also mostly our figures are "@ the wheels" readings & not "guestimated" @ the flywheel

I was in England quite a few years ago & spent lots of time with lots of different mini shops (not as many as i`d have liked tho, never enough time in a trip to England really) but the same thing kept repeating itself & that was all the guys with their "so called FASTEST" mini were chucking me the keys to these supposed awsome wicked fast machines & after a few quick spins around the block , all i could say was that my 1510cc road donk was way way quicker & that was including some turbo minis & K series supposed race powered rocket ships etc etc etc,,,very un-impressed i must say, wish i had my green cooper "S" over there then for those guys to compare what i was feeling. seriously!!! ,,,85hp @ the wheels isn`t such a bad thing for a smooth daily driver able to pull top gear @1200rpms on pump fuel, i wouldn`t say that`s a low HP figure at all

In the past 15 years i`ve probly worked more mini cyl heads in Brisbane than anyone else, (slowing down a bit now tho-> old age, house to re-build, turbo Bimmer twin cams to produce, Down hill mountainbike racing in the way ) & with my dad`s experience & knowledge i must say that without his input (way back when) , then i probly wouldn`t have got these good results, he`s really the brain behind whatever i`ve produced in the way of cyl heads.

credit where credit is due i say & my dad is the brain behind many many quick Australian mini racers (well the quicker of the QLD based ones anyways)

ok,,,now i`m dribbling on way too much again/still, once i start , its hard to stop me

merry christmas

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Hey mate im not questioning your work or experience, as I said just interested.
Agree totally with the dyno bullshit my 8 year old 1380 makes 97bhp and runs 15.5 second quarter miles yet there are several others in our club that have rr print outs with 112bbhp and even 144bhp (differant rolling roads) yet there all half a second slower on the strip.

no worries Smiffy, didn`t take offence at all,,,just me rambling as i normally do

good to see that at least you`re one that understands how dynos differ & how reallity is the real dyno

merry christmas man

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Merry Christmas mate

merry xmas and you should be doing other things other than sitting on the pc on xmas day.

i have a good excuse, ill let you in on it a bit later.

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www.minicranks.com add me to your watch list and come back again soon, under construction.

I'm doing a port and polish job on my 998 head myself. Never done it before, but I decided to have a go. If I stuff everything up then I'll get a 202 head. I'm using a dremel tool with lots of different attachments. This article has helped aswell: http://www.sa-motorsports.com/diyport.shtm

Right now I've enlarged the inlet ports and exhaust ports on the head. Just need to polish the exhaust ones. Then I'll see about the bowls. Not sure if I'll open them up much, probably just polish them. Anyway if anyones interested I can get some pics happening.

Have a good christmas.