jonbill

Thanks, they've certainly worked fine for 3 years with lots of revs, so no real reason to suspect them other than search not showing anyone here using the 68025 springs.

Thanks, yes, they were new Nissan ones. They don't have any damage. It has a high volume pump. Thanks for info on spray bar and lucas zddp.

Hi, I've been running a. 585 lift 307/8 duration cam for 3 years now (8 or 9k miles). A couple of the lobes have just started to lose material from near the tips. And I'm looking for how to avoid when I fit a replacement copy of the cam. The cam is reground from an oiled 1981 f54 l28. I have Schneider 68025 springs with a seat pressure = 125 lb ( I think) Are the seat pressures too much? I could swap for 68022 springs at 110lb. Should I use a spray bar too? Was I just unlucky or used the wrong zddp additive this year? Thanks for any pointers. Jon

Are you trying to install with two circlips per side?

So you turned the whole engine by turning the cam, and the wrong way? Which is to say you turned the crank by pulling on the tight side of the chain? That won't be a problem for the oil pump. Don't think that'll be a problem at all.

Why should you turn the cam at all to take the head off? Once the head is off you can turn the cam if you want. You just have to make sure it's back in the right position when you put it back on.

Great stuff, what was the problem?

I'll post my tune when I get home tomorrow. Do you have a similar setup to me? Looks like you've got 36-1 trigger wheel. Here's a thread I have on the speeduino forum while I was trying to get it to work that might have some useful info. https://speeduino.com/forum/viewtopic.php?f=19&t=2537

I suspect Quaife will advise you to install the circlips before installing the diff in the carrier. You might be better off biting the bullet and taking it out again. As long as you don't mix up the shims under the bearing cups you can't mess up the setup, so nothing to worry about.

It rather depends what you'll do with it. I'd recommend getting this book or one of the others like it. How to Build and Power Tune Weber and Dellorto DCOE and DHLA Carburettors (Speedpro Series) https://www.amazon.co.uk/dp/1903706750/ref=cm_sw_r_cp_apa_i_Ah7PCb8WCD7AH They'll help you pick the parts you want for your use case. First thing I'd do with them is swap them for 45s.

There was a time when the Quaife diffs didn't come with the circlips pre installed and you (or your installer) had to install them before installing the diff into the case. I've read people's troubles installing them after the diff is in the case. The circlips needs to be compressed and pushed square into the driveshaft hole until it expands into its groove. Sounds like yours just wasn't ever installed.

No you shouldn't have to bleed it. Worth checking though that the pin is pushing on the release fork and that the release for is pushing against the clutch cover springs.

I may have missed it, but how did you ensure the motor output drive and gearbox input shaft are perfectly in line? That's the complete one-off so surely the most likely source of errors.

I'm sure they'll be fine. I guarantee the buying has only just started though!

No I think you're right, if you don't go over 6 ish much, stick with the 34s. They'll work as well up to 6k as bigger ones could.

IMO venturi size is driven by the amount of air you need to flow, which is dominated by displacement and max rpm you're going to use. Not cam specs so much. There are a few variations of a formula around. Frank Honsowetz's book has this: Venturi size=sqrt(cylinder displacement * max rpm ÷ 1000) * 0.65 Which for a 2.7 with a 7k rpm used redline gives 36mm venturi size. Which sounds right to me. I have a 2.9 which I rev to 8k with 39mm venturi. Should prob be bigger but that's getting to the limit of 45mm body anyway. Some will say you should have smaller venturi for the street: The bigger the venturi the harder it is to get the transitions between idle and progression and main jets right but it is possible.

I've just finished a Speeduino 0.4.3c ignition only install on my car. It uses a 36-1 crank damper trigger wheel and a TPS with a Bosch clone wasted spark coil pack and igniter setup. Probably about £250 all in but could be done cheaper I'm sure.

My f54 is at 88.5 so 2915 with Kameari pistons and Maxspeedingrods l28 rods. I wish I'd been braver and gone 90. But it goes nicely so can't complain.

These guys sell shims that thick and thicker. http://www.precisionshims.com.au/products/slotted I have them in my engine and would recommend them.

With plugs that cool, I think they'll foul pretty easy if you're not loading it, which could be the case if it's been off the road for a while. I'd stick a new set of plugs in, gapped at 0.6mm

Not sure if someone already mentioned it - check the thermostat. It could be stuck part open, could be in the wrong orienation and unable to open fully

Another update to this old thread, since I looked and couldn't find this anywhere. I just got a Hitachi OUP0016 'turbo' oil pump from Rockauto. The pump itself is marked K11 - no other marks, not even a Hitachi logo. But I opened it up and the rotor is indeed 40mm.

Hi, I don't know the Mikunis specifically, I have Dellortos, but the Mikunis look similar. I have modified the pump jets on my carbs to fire at an angle of maybe 22.5 degrees to correct for the curve of the manifold runners. like this: ..../..\...\../.../..\... So - perhaps someone has tried something similar with yours before you had them. And you or someone in between has had the jets out and put them back in the wrong positions. Are yours really 2 straights ahead and 4 to the right? or something more like mine?