Hi, i just received my new stage 3 head that i bought. However i feel as if it hasnt been finished properly or could still be modified a bit. Are the exhaust and inlet ports meant to be ground out more?.
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| Author: | 1380 K [ Fri Jun 29, 2012 7:17 pm ] |
| Post subject: | Stage 3 port and polishing standards? |
Hi, i just received my new stage 3 head that i bought. However i feel as if it hasnt been finished properly or could still be modified a bit. Are the exhaust and inlet ports meant to be ground out more?.
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| Author: | mickmini [ Fri Jun 29, 2012 7:31 pm ] |
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Unfortunately for you, only the supplier you bought the head from knows what their definition of "stage 3" is. There is no standard for porting a head, since every application is different and every supplier has their own interpretation of what is required for that application. They will generally have a combination of port, chamber, valves, rockers, camshaft, compression, carbs etc that they, and only they, will put together and say this a "stage XXX" level of tune. Ultimately the "stage 3" description is a marketing term that means some work is done to the head. It goes along the lines of stage 1 is changing the exhaust and carby, stage 2 is changing the camshaft, stage 3 is doing some work to the head. (someone more knowledgeable will correct me here i am sure  )
If you have concerns that it is unsuited to your application, you can take it to a local specialist and compare to other heads or have them tell you its suitability. cheers michael |
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| Author: | drmini in aust [ Fri Jun 29, 2012 7:38 pm ] |
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It's a bit hard to tell from your pics, but I'd expect a stage 3 head to have more taken out of the intakes. You could get it flowbench tested, that will give you an idea of what it's like. Here's the one I did at home following Vizards's yellow book, the intakes flowed 116CFM @ .450" lift on GR's flowbench with Mk2S valves. 
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| Author: | 1380 K [ Fri Jun 29, 2012 8:18 pm ] |
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Hopefully these photo's will explain a bit more. I am wanting a great amount of performance out of this head. i cant remember the stats that this head was machined to. Basically my question is. Should i get the inlet and exhaust taken out a bit more? will this increase performance much or will it just be a waste of money? thanks alot. 
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| Author: | drmini in aust [ Fri Jun 29, 2012 9:05 pm ] |
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If it's a 1275 head? those inlet valves are stock 1100S size (33mm). You will get more HP with Mk2S ones (35.6mm). |
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| Author: | miniimports [ Fri Jun 29, 2012 9:22 pm ] |
| Post subject: | re head |
id feel a bit ripped off looking at those pics as nothing has been done to chambers exept a wire brushing did a business sell this? valves look quite sunken in the head and not centred in the seat(even look wrong size) very little effective porting has been done |
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| Author: | miniimports [ Fri Jun 29, 2012 9:37 pm ] |
| Post subject: | re head |
id feel a bit ripped off looking at those pics as nothing has been done to chambers exept a wire brushing did a business sell this? valves look quite sunken in the head and not centred in the seat(even look wrong size) very little effective porting has been done |
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| Author: | Convertible Mini [ Fri Jun 29, 2012 9:39 pm ] |
| Post subject: | Valves too small |
I was going to mention the fact how the valves are way down too deep into the seats. Not very good practice. |
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| Author: | dodge [ Fri Jun 29, 2012 10:06 pm ] |
| Post subject: | |
sh1thouse mate ask for a refund, thats a kero overhaul and vavle lap job for sure porting is a skill , some think massive porst give more power,, wrong, flowing a port is more important, where to remove metal and where to add it in. as for the valves , bigger is better in any case 
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| Author: | simon k [ Sat Jun 30, 2012 12:11 am ] |
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1380 K wrote: those chambers haven't been touched - no deshrouding at all doesn't look like the valve guide bosses have been touched |
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| Author: | 1380 K [ Sat Jun 30, 2012 10:18 am ] |
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So ive been ripped off in other words? i payed $750 for it. what can i do? i bought it through paypal. |
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| Author: | miniimports [ Sat Jun 30, 2012 10:38 am ] |
| Post subject: | re head |
id be having a chat with whoom you have bought it from id be guessing its from an newish business just looking at the pics(dont mention names) as ive seen similar work just say your not happy with the job and would like a refund, or the work you paid for done properly to the head were the goods purchased through ebay as you may have other avenues of recourse? $750 for a recoed head if no exchange was supplied is not out of the ordinary,but of course the job has to be done properly. good luck cheers |
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| Author: | 1380 K [ Sat Jun 30, 2012 11:43 am ] |
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No it wasnt sold on ebay. He had sold a 12G940 head stage 3 on ebay and i asked if he had anymore. He got one machined the same as the one listed. i was told this one was a little closer to being a stage 4 head. Payed through paypal. He did not do the machining, an engineering place did.(best not mention company) Im just not sure what ground i have. Probably non. Sorry for my lack of knowledge about modding heads, but is this not a port and polish? All the other work stated in the add seems to of been done. Not sure how much the proper machining and cooper s valves will cost. |
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| Author: | mickmini [ Sat Jun 30, 2012 12:28 pm ] |
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5 years ago Graham Russell charged me $600 to do my head, which included the porting, chambers, skimming, cutting valve seats for larger inlet valves. Graham had K-lines inserted in the valve guides and reamed for $120 (subbed out to someone else). I supplied the new inlet valves and he reused the old exhaust valves. The specifications for the head were determined in consultation with Graham taking into consideration the RE83 camshaft, the standard rockers (and future upgrade to 1.5:1), the new pistons, crankshaft, and rod combinations. This is what Mat rightly calls the package. The price you paid would be about right if the above described work had been done. From the extra photos and others comments, this is clearly not the case. However, as i pointed out before, describing something as "stage 3" or "nearly stage 4" is just marketing bu11$h1t, and you took it to mean something specific. It sounds like the seller does not even have an idea what those terms mean or should mean, especially seeing as he did not do the work himself. If the seller had described the head as having the above work done, with specific dimensions etc, and had photos indicating it, then your case would be good that what you received is not what was described. If it was done by a general machining company, they were probably tasked to skim the head flat and re-seat the valves. This is what looks like they have done, and if not specialist A-series head modifiers, would not know what else to do for performance. cheers michael |
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| Author: | Morris 1100 [ Sat Jun 30, 2012 12:35 pm ] |
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It wouldn't be a particular mob in Melbourne that had a recent thread about them would it? Sells freshly painted stuff on Ebay. |
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