TLicense Posted May 4, 2009 Share Posted May 4, 2009 Perhaps someone can help me. I've just built the cylinder head for my engine. I'm using Ferrea valves, retainers, valve locks and seals. These are going into a brand new stock cylinder head along with stock buckets and shims. Lastly I'm using HKS 264 camshafts which require a clearance of 0.3mm +/-0.03mm on the exhaust side. Using my old shims, I measured gaps of 1.2 - 1.3mm. After measuring the shims it means I need shims between 3.7 and 3.9mm. The problem is that the largest shims available from Toyota is a size 17 one that is 3.3mm. Has anyone else had this problem? If so I presume custom shims were made? Quote Link to comment Share on other sites More sharing options...
TLicense Posted May 5, 2009 Author Share Posted May 5, 2009 Right, I've had a good look at this. It seems the valve seats either need to be cut on a brand new head, or the head needs to be replaced. Because they seats aren't right it's holding the valve too low, meaning it would need more shim to get the correct valve clearance. Hopefully I'll get it replaced under warranty.... Nothing's ever easy! Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 5, 2009 Share Posted May 5, 2009 You mean Toyota supplied a new head that did not have the valve seats cut? If so then that's amazing. Are you sure the valves are the same length as stock? Quote Link to comment Share on other sites More sharing options...
Matt H Posted May 5, 2009 Share Posted May 5, 2009 Suprised to hear that too Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted May 5, 2009 Share Posted May 5, 2009 The valves aren't the same length as stock so the seats will need to be cut. The guy that does my heads for me hates me when I give him aftermarket valves to fit! Quote Link to comment Share on other sites More sharing options...
TLicense Posted May 5, 2009 Author Share Posted May 5, 2009 They valves are definitely the same length as stock. However on closer inspection it's the valve face angles that are different between the stock and Ferrea valves. So, basically my earlier conclusion of the head seats being the problem was wrong, it's the valves. So I need to get a local shop to grind the valve faces.... Quote Link to comment Share on other sites More sharing options...
TLicense Posted May 5, 2009 Author Share Posted May 5, 2009 Ah that'll be the problem! Seems I've been sold 1mm oversized valves instead of stock. That'll explain a lot! Quote Link to comment Share on other sites More sharing options...
SimonB Posted May 5, 2009 Share Posted May 5, 2009 I think that even the stock sized Ferreas use a different seat angle and therefore need the seats recutting. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 6, 2009 Share Posted May 6, 2009 YOU DO NOT sink valves to make up clearances, it'll pocket them in the head and kill flow. You want valves of the correct length, you often find Yank valves are a bit generic and if it fits the guide, just about fits the seat, and the collets are about in the right place they expect you to use ludicrously thick shims to make the clearances tight enough. Silver steel, a capstan lathe, sending for heat treatment, and then ages on a surface grinder is probably the next step. If you tell me you aren't calling Ferrea every name under the sun by the time you have made and fiddled with 32 shims from bar stock I won't believe you Quote Link to comment Share on other sites More sharing options...
TLicense Posted May 6, 2009 Author Share Posted May 6, 2009 Chris, I think you missed a bit. The problem was due to the fact the valves a 1mm oversize so I need to cut the seats to suit. The valve length's are pretty much spot on half way between top and bottom tolerance. I didn't order 1mm oversized valves so I wasn't expecting it to be a problem and it caught me out. Having 1mm oversized valves will probably help the performance of my twins so I'm happy to go with them. Before I discovered the cause of the problem, I spoke to a couple of local engine shops about making shims up. The most well regarded local shop flat out refused to do it. It was them that prompted me to investigate further to find what the cause of the problem was. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 6, 2009 Share Posted May 6, 2009 I missed that bit! Sorry Tony. Didn't realise they were 1mm oversized. Quote Link to comment Share on other sites More sharing options...
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