Engine re-build...the joy!

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Postby peterg » Wed Oct 25, 2006 6:30 pm

12 1/2% increase in lift! Thats not bad......didnt want too much duration with what I do. No point in bogging down out of corners.
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Postby clee » Wed Oct 25, 2006 6:34 pm

Proof of the pudding :wink:

Was it very damaging the wallet :?:
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Postby peterg » Wed Oct 25, 2006 6:40 pm

£188 delivered........thats not too steep I dont think.
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Postby clee » Wed Oct 25, 2006 6:49 pm

I think that's a good deal .Can't be a quick process on a unusual item, my worry with these things is evaluation .
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Postby peterg » Wed Oct 25, 2006 6:56 pm

They have a lot of set patterns that apply to more than one engine. I got Fiat twink cams cut to a Ford BDA pattern many years ago....the same will work for the GTA....its probably a Ford Essex turbo pattern or something similar.
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Postby David Gentleman » Wed Oct 25, 2006 8:22 pm

peterg wrote:They have a lot of set patterns that apply to more than one engine. I got Fiat twink cams cut to a Ford BDA pattern many years ago....the same will work for the GTA....its probably a Ford Essex turbo pattern or something similar.


Trust me, its simpler than that. They will simply grind the heal and sides of the lobes in a symetrical fashion, and this automatically raises the lift and increases the duration...

The cams I do are 276 duration with 2mm extra lift, as you cannot do one without affecting the other by an increasing amount, unless metal is added to the cam or they are new castings from blanks.
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Postby peterg » Thu Nov 02, 2006 5:21 pm

Well its all going swimmingly so far (I hope). The bottom end is back together and as far as I can tell from my measurements the liners are seated with the required 0.2mm protrusion.
I know I wasnt going to do anything with the heads, but having had a good look at them they are bloody rough!!! The inside of the ports look as though a crippled blind man with some kind of medieval gouging device has cut them out after consuming a bottle of vino :lol:
Johnathon at the RR has built himself a flow bench and having spoken to him he will do a full flow and port (with 3 angle valve seats) for around the £300 mark (both heads) or a basic clean up for a bit less.

Is it worth it? Are there worthwhile gains to be had???
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Postby clee » Thu Nov 02, 2006 5:42 pm

Got to be worth a go at that price 8) He can practice on yours :lol:
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Postby gt5 » Thu Nov 02, 2006 6:16 pm

i think it will be worth it as seen as you have the cams not sure what gain you will get but all helps,300quid is very cheap i thought prima were cheap at 500quid but i suppose it depends on how many man hours have gone into them my bro has just sold his old head(gtt) and ctm did the work on that they are not cheap but very good at what they do
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Postby David Gentleman » Thu Nov 02, 2006 7:27 pm

gt5 wrote: i thought prima were cheap at 500quid but i suppose it depends on how many man hours have gone into them


You have to weigh up what is actually done to the head though..

Many firms spout, porting and polishing, valve seats etc, but if you weigh it up, the only real gains are from increasing the valve size and opening up the ports **if they are the last restriction**, ie, whats the point opening up a 2" long port in the head from say 40mm to 42mm, when the inlet manifold that connects to it has a tract 5" long and is still 40mm..

Its like having a peice of pipe, enlarging a small section of it and saying it flows better.. :lol:

Its all different in the realms of side/downdraught carbs where youd get the head ported, then fit a nice big set of 45's straight off the side of the head, but in these days of fully casted EFI inlet manifold, unless that can be remanufactured with larger runners, you don't really make the most of it..

..but bigger valves, still have more suck, at peak and part openings, and is the equivalent of increasing the duration as more air is flowed the moment the valve opens..
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Postby simontaylor » Thu Nov 02, 2006 7:29 pm

OMG, "Steve" has a bro too.
I wonder what his name is ???
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Postby David Gentleman » Thu Nov 02, 2006 7:29 pm

£300 is a cheap price though, when you consider it is TWO heads. They guy does remember that you've got two heads Pete..? :wink: :lol:
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Postby David Gentleman » Thu Nov 02, 2006 7:30 pm

simontaylor wrote:OMG, "Steve" has a bro too.
I wonder what his name is ???


Stephen..
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Postby peterg » Thu Nov 02, 2006 7:42 pm

David Gentleman wrote:£300 is a cheap price though, when you consider it is TWO heads. They guy does remember that you've got two heads Pete..? :wink: :lol:


I only have one head actually!! :lol: :lol:

He charges £220 for a 4 cylinder 16valve head so he guesstimated at £300 for 2 6valve heads. That was with the 3 angle valve seats....he said that if it was a straight forward clean up it would be less. Money is tight at the mintue so if there arent any real gains to be had I dont see much point in going there.

GT5......Prima are never cheap!!!
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Postby peterg » Thu Nov 09, 2006 6:24 pm

I have the heads back on and torqued up. The question is do I have an engine with even or offset crank pins????
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