Jake you were right about the 12 and 28 timing!!

This is the place to discuss, or get help with any of your Type 4 questions.
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Plastermaster
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Post by Plastermaster »

Joe, it sounds like you're still not there yet. The gains you have realised are due to a more complete burn of the A/F in relation to the position of the piston. If there is any rpm area that is not doing as well, there must still be either timing or fuel issues. I guess with carbs you can only do so much to optimise fuel across the board. Perhaps the Mallory has its limits as well, but you might not be done tuning yet.

Ron
MASSIVE TYPE IV
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Post by MASSIVE TYPE IV »

He has a stock cam...... Thats as good as its gonna get..
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Plastermaster
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Post by Plastermaster »

MASSIVE TYPE IV wrote:He has a stock cam...... Thats as good as its gonna get..

AAWWWW.... :( I guess we'll be happy with the big improvement. Its always a great feeling when you do a good upgrade.

Ron
NextGen
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Post by NextGen »

Jake and Plaster you are both correct. Stock cam yes but I believe I will get a bit more I increased my idle jet back up to 55 which has improved the range I felt a lose in. The reason I went for the smaller jet was because of the unburned fuel issue. Which turned out to be 6 psi of fuel pressure. So now I got the snail in one hand and a wrench in the other, I am fully armed and ready to TUNE!!! At this moment I am very happy with the cooler running an higher top speed.

Stay tuned to Pulley Post.
Joe
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Peter
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Post by Peter »

Hello Mark... just seeking to learn here...concerning the 40F. change..was this change at idle or all thru the RPM range??? quote="Mark the canuck"]The nice thing about programmable ignition is I can prove that Jake is right in within minutes. By the seat of my pants I can't tell a difference in power, but at 28 degrees my head temps went down at least 40F.[/quote]
Peter
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Post by Peter »

are the temp changes the same for a "carbed motor" as for the FI.......................
MASSIVE TYPE IV wrote:Vacuum effects the maps.. The cam I set you up with was designed to have higher manifold pressure at lower RPM, therefore it will compliment The EFI tremendously..
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Mark the canuck
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Post by Mark the canuck »

Running at all speeds, I was running at 32 degrees advance and my head temp was a hair under 350F, so I thought that was great.
When I knocked it back to 28 degrees my temps went to 300F.

My ignition map now looks like a bell curve, 12 to 28 and then back down to 24 degrees. The Jakester was right again, retarding the timing after 4500rpm works real good. The old tach needle just flys in the upper rpms because of this little trick. Thanks Jake!

BTW I'm running SDS EFI with crankfire ignition, SDS EM-4F
MdR
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Post by MdR »

Mark the canuck wrote:BTW I'm running SDS EFI with crankfire ignition, SDS EM-4F
What have you used to get the cranksignal, humm that sentence reads badly - how have you fitted a crank sensor wheel (toothed - 36 + 1?) and crank position sensor?
Some pics would be really helpful.
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Mark the canuck
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Post by Mark the canuck »

how have you fitted a crank sensor wheel (toothed - 36 + 1?) and crank position sensor?
Some pics would be really helpful.
Nope on the toothed wheel...My SDS crankfire has two sensors and three magnets, one sensor and two magnets are for firing. The other sensor and magnet (reversed pole) is for sync.

to see my install go to:

http://www.shoptalkforums.com/viewtopic.php?t=56845

There's a link at the top of the page and an update link at the bottom.
MASSIVE TYPE IV
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Post by MASSIVE TYPE IV »

Mark, Glad it worked well for you!

I found this out one when a dizzy would not advance all the way and the engine ran like crap down low but really liked to rev!! With an EMS system this is good for some mega HP gains!
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Ephry73
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Post by Ephry73 »

I have a question on this timing. Can this setup be used with an aftermarket camshaft as well as stock? The reason I ask is that I have been trying to ind out what the perfect timing would be for this Trubo Camshaft i bought. 260* @ 50

Ephry
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Crimson_Axe
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Post by Crimson_Axe »

Are the mallory settings of 12, 28 @ 3000 and back down for smaller engines or most engines?
ggggarret
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Post by ggggarret »

i've got a stock 2.0L that i JUST re-installed EFI on along with a mallory unilite (vacuum assisted) and an msd 6A box. are ya'll suggesting i disconnect the vacuum line and run just the centrifugal advance? i have my timing set at 8.5 at idle at 28 at about 3500 but with the vacuum attached the advance gets up to 42 at 3500rpms. i was told this was normal and ok, is this not true? i just installed a head temp sensor and it looks like i'm running up to 350+ pretty quickly when i haven't even had it on the highway for more than 2 miles. this temp concerns me a bit and i'm headed on a 9 hour drive in the morning so it would be great to make whatever adjustment i needed to make before i get on the road.

thanks in advance.
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raygreenwood
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Post by raygreenwood »

On the stock injection, you will get better control over idle and idle mixture with about 10-12 BTDC at idle. Running upwards of 42 degrees advance on the vacuum unit....is "common"...but nowhere near normal.
A great many 914's as well as 411/412 engines countered this problem by using an adjustable advance stop screw installed in the dome of the vacuum can. The arm # of that unit was 917. You can install one yourself with like a 3-4mm press in aluminum insert with a fine thread screw and locknut.
One of the problems that is getting you actually...if this is the correct advance unit...is that the vacuum retard...if you are using it...is draging your timing down too far at idle, so you have to twist the dizzy too far around just to get 8.5 degrees. That means the top end gets too high.

What you can do...and you can do this either if the vacuum retard is dragging you down or not....is to tune the engine with vacuum hose connected on advance side...so the timing light shows a maximum advance of 27-28 BTDC at 3500 rpm. hen you let off the gas....you will probably stall. Don't worry. Turn off the car. Mark the dizzy position. Then take the dizzy out...and remove the can. See that notch in the arm......the one on the inside that goes up aainst that round pin riveted into the side of the bracket on the vacuum can? That is the stroke stop for the retard. With some tweeezers and patience, you can either wrap teflon tape around that peg ...or a similar high temp plastic...or sometimes bend it a litte...to not let the arm retard all the way. Put ot back in and see what your idle timing is. Experiment to give reasonable idle timing. This will not affect the top end advance if your timing is set to be correct when that can maxes out. Just be carful that your TDC is correct when all is done.
The best adjuster I have found for this peg, is a section of a cheap nylon rod or bolt, with a hole drilled in the center....offset (eccentric)...so you can slip it tightly on and twist it to get adjustment. Ray
ggggarret
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Post by ggggarret »

seeing as how i'll be on the road and don't have time to really get into this - would it be a bad thing for me to just disconnect the vacuum line to the dizzy and let it run the 8.5/28 advance settings with just centrifugal until i get back?


looks like i'll be travelling with my timing light and other tool goodies.
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