Search found 1485 matches

by Steptoe
Fri Dec 07, 2018 2:41 pm
Forum: Propane Forum
Topic: Adjusting timing propane engine and impco 425 mixers
Replies: 23
Views: 144

Re: Adjusting timing propane engine and impco 425 mixers

I have put the softesd mech springs in already is that a good id. Be careful doing that, you may find that at lidle the spring is not strong enough to hold the advance weight in This results in it moving out, advancing the timing/ that increases rpms, Since you are running on the idle circuit only,...
by Steptoe
Tue Dec 04, 2018 4:26 pm
Forum: Propane Forum
Topic: Adjusting timing propane engine and impco 425 mixers
Replies: 23
Views: 144

Re: Adjusting timing propane engine and impco 425 mixers

Make good use of the forum search function.. detailed how toos on changing weights.. fixing weight to establish a curve on paper, filling off/ reshaping weight tails to limit advance.. making stops for weights and VA s etc
and lot of other stuff.
by Steptoe
Mon Dec 03, 2018 2:42 pm
Forum: Propane Forum
Topic: Adjusting timing propane engine and impco 425 mixers
Replies: 23
Views: 144

Re: Adjusting timing propane engine and impco 425 mixers

At any given rpm and load combo there is approx +/- 1.5 deg tolerance for best performance.. racing even less. To do that you will need data logger and at least knock sensor 02 sensor, preferably IMAP sensor. I have spent many decades dialing engines, old school thru to modern data logger/ sensor te...
by Steptoe
Thu Dec 28, 2017 5:42 pm
Forum: Messages
Topic: Forum Logo
Replies: 10
Views: 3994

Re: Forum Logo

Like it
not only that
and colour/ designs match the subject, something many over look.
10 out of 10
by Steptoe
Wed Nov 15, 2017 3:38 pm
Forum: Propane Forum
Topic: mounting a IMPCO relocation arm
Replies: 4
Views: 509

Re: mounting a IMPCO relocation arm

Did you use the mounting holes that are on these adapters for extra support? A must.. a scrape bit 4mmx 15mm bar, bent and couple holes drilled each end.. one end mounts on a convenient point on the mixer extension.. mounting point or section joining nut/ bolt, down to a convenient exhaust, or powe...
by Steptoe
Wed Aug 30, 2017 4:06 pm
Forum: Propane Forum
Topic: Max 32° mech. adv. for low cr engine: confirmed
Replies: 11
Views: 1116

Re: Max 32° mech. adv. for low cr engine: confirmed

Fun thing to notice was, that it liked timing to be pulled back from 32° to 30°, from 3000 to 4000rpm This is where the cam starts to work.. higher rpms and the overlap/ duration and cylinder pressure tend to increase a few lbs at this point. The dyno has AFR and knock readings etc? Dyno guys tend ...
by Steptoe
Sun Jun 18, 2017 7:33 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

I have been messing with LPG, classic, vintage compressions, re designing old engines, compressions , custom cam designes to run on modern fuels since the early 70s. All I can say it I get damn good results.... for the last 30 odd yrs, and with technology and data loggers etc becoming affordable in ...
by Steptoe
Fri Jun 16, 2017 6:41 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

Dont believe everything about electric fans.. If going to replace a fixed fan.. yes.. If a clutch fan.. no.. forget the marketing propaganda to sell electric fans (like the 'flexi fan bs) .. . there is no load on a clutch fan when it is not needed.. this is one of those old wives tails.. like HEI wa...
by Steptoe
Thu Jun 15, 2017 5:41 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

Eventhough, after everything I've done to my car, I still can't produce any MPG's to be proud off, as I'm currently only netting around 12mpg. Im between 15 and 16 mpg Also musty go right back to basics.. The amount of mixture used per mile is directly related to the volume moved by the engine per ...
by Steptoe
Wed Jun 14, 2017 4:53 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

Changing timing AND AFRs makes a huge difference in economy and power. Simply changing one or the other may only be slight, depending how far the other is out. Any timing change.. be it at idle or in the rpm range will require a a change in mixture....unless the timing is over advanced... and visa v...
by Steptoe
Wed Jun 07, 2017 4:47 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

Forget trying to relate petrol tuning (any specs) specs to and other fuel... doesnt work. I mention dial in.. this is what you have to do...Dial in means establishing the best tuning specs (as one gets the tuning specs in the manual) idle rpms... that is best stable idle at good afr..."best " means ...
by Steptoe
Tue Jun 06, 2017 8:51 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

Billhilly I hope I'm not coming across as harsh but there is a lot on the internet and much of it is generic or wrong. I will also add.. most old school pre dizzy mechanics didnt/dont even understand timing and the background behind it.. Damn near ALL modern mechanics.. or 'technicians' who only kn...
by Steptoe
Tue Jun 06, 2017 4:56 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

Little to ad to storms I take a slightly different approach in setting up timing.. both end up achieving same results...method in older posts Few things you need to understand. 1/ Never dial in timing increasing advance...as advance increases the tone changes, sounds better..this is sort of like a o...
by Steptoe
Mon Jun 05, 2017 4:39 pm
Forum: Propane Forum
Topic: AFR numbers on dual fuel setup/300A tuning tip?
Replies: 42
Views: 3424

Re: AFR numbers on dual fuel setup/300A tuning tip?

Thats what I run at.. or very close. There is far more than just getting the O2 right, you need to combine that with the timing curve. The timing curve will vary due to load on the engine.. ie final gear ratios, weight of the vehicle and if running EGR or nor Also Vacuum advance at idle (enables low...
by Steptoe
Wed May 24, 2017 1:27 am
Forum: Propane Forum
Topic: Q-Jet Throttlebody & 425
Replies: 8
Views: 1065

Re: Q-Jet Throttlebody & 425

Mine is a dual plane.... no issues right out to leaning out high 4K / low 5K rpms sb 355 chev... which is around where it should be.. if anything a little lower.