The beast lives. Turned the key and it burst into life. Sounds very very quiet up top. Scarely quiet. (Need to check the valve clearances, to make sure Ive got some..) Sounds sweet. Next job to complete the JMR gear linkage (nice job Jason) and finish the ancills so its driveable. Then some RR time. Can't wait.. (although will prob have to, due to other 'life' committments) Quite optimistic tho...
Been to the r.road this week, and no nasty surprises. Torque peak is a bit low (?) but the overall result is reasonably pleasing. Can't brag about huge power, but the point was to try and jet it/time it. Ended up with 170 main jets (!) so its going to be thirsty.. If someone will put a picture up for me I will email them the power curves. Maybe Mr Toyotatec will give me some guidance on reading these and maybe suggest some further improvements. Never, ever too old to learn
No problem. Send me the plots via pm or email and I will try my best to analyse. PS we only stop learning when we are dead!!
Great offer, I will take you up on that, and probably stick the plots on here, for all to comment on, good and bad
Yeah, I know. 170's seem wrong for 38's. Maybe the rolling road 02 sensor is out of cal.? Engine made more power though. Scanner is acting up, so trying to get a plan B in place
If it needs it it needs it, you cant argue with the power going up!...150-160 would be the norm tho...I've got 160's in my 48's on 39mm chokes for example...list up the whole jetting combination Jon, or pm it over. What power did it make in the end?
Old thread resurrect. Building a 9A copy of the above motor, for my mk2. Short half engine built, playing with the head now. Its fully ported, knife edged and a really nice job. Has PO - FO 1103 stamped into the back. Anybody recognise who's done the porting? Anyway, come to lapping the valves in and 8 of 16 have some pitting to the seats. They need replacing. Std sizes The inlets are a race shape with a waisted stem (7 to 6mm) and std collets. The exhausts looks like std, but are a diffierent colour (material?) Who is the best supplier to match these? I want to post a couple to them to ensure I get equivalent ones. I will update this thread with the build progress, if anybodies interested. Jon
did you use the mech cams in the end? I think the elusive 100bhp/litre is down to the soft ramps on the hydro cams but I could be full of it. If minis will do 100/litre then a 16v golf head should
Yes I did use the 300 degree kent mechs in my ABF 2L (first part of thread), and I was happy with how it went on its only outing so far. (local sprint) This build should give similar results. Its a 9A and has slightly unknown cams (full race, haven't got the timing figures yet: these are not an off the peg grind) but carbs and exhaust, compression etc will be similar. Going for 40mm chokes in the 45's , the ABF is on 38's. I like how clean the engine revs on mech cams, there is a difference, difficult to quantify, but I believe they rev freer. As an aside, I still cannot get my head around why you cant shim up a hyd cam with mech followers. I have been told numerous times you can't, but I still don't understand it. Perhaps someone can explain Jon
You can machine the hydro interior bit out so you are left with just the bucket and then fit longer' tophat' lash caps. When my engine came to me in it's original state it had these fitted (modified hydro followers), worked fine. Kent can supply overlong lash caps to machine down (as I'm sure you know).
Not quite what I was getting at. I know you can mod a hydro follower to be like a mech one. (potential saving 100-200 set of 16: no thanks, i'd rather just pay the money) No, what I was getting at is using a hyd profile with mech followers Jon
Ah, I see. I don't know what the problem would be. Is the base circle different? I always assumed a hydro profile was 'softer' on pickup, if you get what I mean, to give the follower a chance. Be interested to find out exactley what the actual difference is myself
Thanks Jon, I'm away all week, be back at the weekend, there are people there to take delivery though. Give you a shout when I'm back Saturday.
Smoke, mirrors: If it is softer on the ramp, why wouldn't a mech follower work on a hyd profile? As Ive said before, the danger of the interweb is 'group think'' Jon
the mech grinds are too savage and squeeze the oil out of the tappet, allegedly, so when using mech the valves accererate faster for the same duration they are open further for longer, again, allegedly
