I was going to post this in Recardo's thread, but instead of hijacking with all my pictures here's a separate thread... I bought a polished / flowed head off eBay quite some time ago. It had been done by an enthusiast chap who claimed to be a valvetrain designer. I've never been quite sure exactly how significantly this head has been worked on as I'm no expert. However, I had it fitted to one of my 16Vs until I took it off recently, and the car was never properly tuned up when it was fitted, but it did seem to go rather well and the engine sound was very nice! Only reason I took the head off is because I want to use it on the block that I'm rebuilding. If anyone cares to, I'd really be interested in comments about the following pictures I took of the head before it was fitted. I'm just curious about what you guys think of the standard of the work done, etc. I do fully realise that nobody could give tell from pictures how this exactly head would perform. I'm thinking of taking it to an engine shop before refitting just to get the guides, etc. checked over. Edited by: Trev16v
im not an expert, but looking at the inlet ports compared to the other thread it looks like they could've been smoothed a bit more and the exhaust ports could be rounder
The finish doesn't look as smooth as my head ( and the one on the car) but that's not always a bad thing where heads are concerned.
probably going to get shot down in flames here, however I was speaking to a head freak a couple of months ago about polishing. He said that he only polishes the exhaust outlets and leaves the inlets rough to assist mixing.
Did anyone ever see the pics of Oddballs 200+bhp Astra 16v head? - The ports looked rougher than those in Trev's pics
I did expect quite a mixture of opinions I do recall reading a comment on here once about a 'rougher' inlet possibly being better in some ways. But I guess that's one of those things that could be debated until the end of time. Although they look rough in the images, they feel very smooth to touch.
I have had a few heads done by Portformance in Warrington. He really knows his onions, and he showed me on a flow bench the difference between a ported and 'polished' head, and one that was just ported. The polished one didn't perform anywhere near as good as the other. He said its down to surface area, and the slightly rougher one has a greater surface area, helping combustion. The ports he did on my old 8v looked rough like the ones in Trevs pic, although in mine the valve guides had been shaped to blend with the ports too, as on the bench that showed up as a big restriction. And the rough looking ports must have worked, as that head was the best flow figures he'd ever got on an 8v Golf Head!! And the engine(2.0 8v, that head and Piper cam, TSR manifold) made 159bhp and 148.9lb/ft on standard injection! www.po-fo.com Under Development, but his numbers there, give him a bell, he's a really helpful, genuine bloke
Yup looks a bit rough, and its been skimmed to death! How it flows will be a mystery unless you get it on the bench. Shape wise, he's taken the guide supports out and generally just taken some meat out. A couple of valve stems look a bit rough too, like he's sanded them with some rough paper to clean them up. Hope you didn't pay too much for it. Edited by: Hotgolf
Nothing that can't be sorted though mate, probablt won't take alot, but prey it doesn't need another skim!
I could sell it on eBay again as a **RARE!!** HIGH COMPRESSION 16V HEAD! L@@K! I would ask how you can tell it has been skimmed so much, but when I get a chance to compare it with my other standard 16V head, I'll probably see for myself. Hotgolf - I will still be interested in a 'box rebuild in the future. Still trying to figure whether an 020 will be suitable for the engine I'm building though.
I have a cylinder head for the 16v and was thinking of doing some work to it but it has done 215k miles. Waste of time doing anything with it ? or wouldn`t it matter.My biggest concern is the potential wear on cam bearings. Trev ,how many miles has that head done.?
I don't know how many miles this head has done unfortunately, mate. I never realised it had been decked so much. Shame. I would like to get it seen to by someone who defintely knows what they are doing, but I dunno who really. Maybe the machine shop I'm going to use to get the overboring done, etc, will be able to advise me.
very rare you have a problem with the cam brgs, have the guides been replaced? best thing is to flow it and then fit the guides, seen quite a few cars with the end of the guides removed, with some its ok but on some they become too shot.
