Weber selection and initial jet tuning

[blodi]

34 minutes ago, 240260280 said:

Did the Dyno use a wideband?  It would be interesting to compare.

I wonder where you can get 5 more HP?

They didn’t. Just had him record on mine. 

I know 5 more hp is killing me! 

37 minutes ago, 240260280 said:

Weird, I was just thinking of you and this earlier today.  Must have been ths Z FORCE.

 

195RWHP is F'n AWESOME!!!!!

 

For the high RPM scatter, usually a distributor refresh with lube can help the high end.  Sometimes the spindle teeth meshing with the worm on crank snout cause timing variation at high rpms according to Frank Honsowetz. He recommends brass teeth. Also it could be poor electronic components in the Pertronix.

Ok.  It’s an odd issue that I did notice the last week or so on the road  6k+ it starts breaking up. You can hear it in the video.  Power was leveling off before the break up, so I don’t think I’m missing out on more hp. But, still need to sort it out.  Oh we tried upping the fuel pressure for one last run and that had no impact on the break up. After I noticed it last week I backed off the timing a couple degrees and I must say that the butt dyno noticed an improvement.  Had it at 40 degrees at full advance before (that’s what Larry told me) and I backed it down to probably 36-38 now.  Is seems there isn’t the same lag from idle to main circuit there used to be.  So I think you may be right on your earlier request to back off timing.  

 

[240260280]

Yes. For higher compression engines, less maximum electrical  timing is needed.

For mechanical valve event timing, moving the cam timing (at sprocket) to #1 position may help breathing and give you more WOT HP.  ?

Edited July 14, 2019 by 240260280

[Patcon]

I think those numbers are great!

Can you summarize your engine set up for a reference point?

[blodi]

On 7/13/2019 at 9:48 PM, Patcon said:

I think those numbers are great!

Can you summarize your engine set up for a reference point?

L28 F54/Flattops, .040 bore,  E31 Head which is ported/etc, 500/300 cam, 6-1 header, pertronix igntition.

 

I looked at the logs last night from the dyno and they are basically identical to the last ones I posted. 

 

 

[240260280]

Thanks. I wonder if something is coming  loose in the distributor to cause the break up?

 

btw the fuel pressure change should not make a difference for carbs.  It is an EFI trick to flow more fuel.

Edited July 15, 2019 by 240260280

[Patcon]

2 hours ago, blodi said:

L28 F54/Flattops, .040 bore,  E31 Head which is ported/etc, 500/300 cam, 6-1 header, pertronix igntition.

 

I looked at the logs last night from the dyno and they are basically identical to the last ones I posted. 

 

 

Who did the headwork? Any idea on compression?

[blodi]

3 hours ago, 240260280 said:

Thanks. I wonder if something is coming  loose in the distributor to cause the break up?

 

btw the fuel pressure change should not make a difference for carbs.  It is an EFI trick to flow more fuel.

I'll try to take a look. 

 

1 hour ago, Patcon said:

Who did the headwork? Any idea on compression?

The whole engine was built by Ritalon Engineering.  No exact idea on compression.  It runs a 2mm headgasket but, the had has been shaved. 

[jonbill]

I used to use a pertronix igniter and it had similar misfire problems over 6k. I'd try a 280zx distributor if you can borrow one from somebody near.

[blodi]

For a 280ZX..I need the dizzy itself like this...

https://www.ebay.com/itm/Distributor-Cardone-31-1002-Reman/253366339964?fits=Model%3A280ZX&epid=74256721&_trkparms=ispr%3D1&hash=item3afdcf897c:g:4RIAAOSwX6dblobb&enc=AQADAAAB4KX%2FKt4E1xf3SDqEdBclaYbknJR1D7xxSyWAHWyAwd3iiP23x1ImQ9W3smU2bYu1PB2xzFApuJfqbvy2KPKERnHx5uWwMz3eTbR88AJ3UKzBwhx5N6tcs%2BkOUsxVKvB66n9KFO%2FU9b7sNiWIkWeOzwnEqcM3ktuCsG9O5zSov%2FobznkrfgdYiSOy2fYT%2FMZ87wuJsBgWei%2BtOaQtIdQ5Auqdl5Tq67B9rTXB3qVoauV%2FJgp66TWueMVaMaar7VB6gpT5ZIflVj6U5Xz9EGkCHIktF4xqsZ89D8R70g%2FqSTECPpyrCNN4RVivofl%2B5hRwYmlGq1dQ8HOZ0Q5jxPZedVIHIqw9Lze6YVcUemU5KhzBVqDyCOvJb7hWnNoOO4KcGDHH6HF6JlFSv9Vi26RBKjcpiwC%2ByQ36Vtl3rZwNcoahFW2qbwjKeA2nPbz4bA35yjPYGQQvLxNLjNTokgQVAhJ3Fe7WG3M5J1phBup6awZHoO%2F3TLMPZ1KX8FX7cOS6BKy5I4A%2FVIdiKC5oTdeS7p1X7NcTahOVEvhktufFdI%2BFrnTi30GSuLsk2EnnsNlqH1ST4ytLy1swHun9dNx6ywfq8ox0nYufMZRQUmMJ%2B5HLn6wirXNREEXH9IVkC1Kuag%3D%3D&checksum=25336633996461ef88fef06644f7a1a438860a0e4a19

 

And what else? Do I put my pertronix components into that? 

 

 

[Patcon]

18 minutes ago, blodi said:

And what else? Do I put my pertronix components into that?

Nope, you just use that distributor, stand alone, with an appropriate coil and a little wiring

[blodi]

Ok. Found it way cheaper at Summit..

https://www.summitracing.com/parts/aaz-31-1002/applications

 

Found some decent install instructions as well.  I'll order one up and give it a whirl!  Will my stock 240 tach work ok with this swap? I think I read they arent' compatible and that is why I opted for the pertronix. 

[gundee]

I think I would just use my Pertronix pick up to trigger a CD box such as a MSD or Crane.

I think you have the compression to justify the need for a CD ignition.