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alexg89

KA with sidedrafts

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If you truly do not have much vacuum I would say the cam is timed wrong.

The first L block head gasket I ever replaced I got the cam timed wrong when I put it back together, it barely ran and was very slow to rev but it idled alright and started just fine.

I didn't go back to see if you already talked about this.

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Yep, lots of confusing info coming to light here.

 

You had the cam gear off in the past?

 

Your timing at idle shows 30 degrees and runs great?

 

The oil pump spindle may be a tooth off?

 

Time to get back to ground zero.

- Start with verifying TDC (screwdriver down #1 spark plug hole, then check the mark at the pulley).

- Then check the clocking of the oil pump/distributor drive spindle (the dots line up before you stab it home).

- Check your cam timing (with various methods. I like the split overlap method, but it does require a dial indicator like this - https://www.harborfreight.com/clamping-dial-indicator-63656.html?cid=paid_google|*PLA+-+All+Products|All+Products|63656&utm_source=google&utm_medium=cpc&mkwid=sKE0GgBvZ|pcrid|327822404853|pkw||pmt||pdv|c|slid||product|63656|&pgrid=71439424048&ptaid=pla-296227499965&pcid=1688396772&gclid=EAIaIQobChMI8bDD2tHw4QIVoRx9Ch2qhgjVEAYYAiABEgJcJfD_BwE

- Now you can fire it off and check ignition timing.

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The pump being off a tooth or more will place the distributor in a position where you can't turn it enough to get the proper timing. Then it will need to be clocked into range

 

30 BTDC is insanely advanced, I would even say impossibly advanced. So assuming this is not possible to run, then either the timing light is set or read wrong, the timing scale is wrong or crank pulley is marked wrong.

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And if the crank pulley is that far off, then what does that say about the cam timing?

 

Too many possibilities here. Start checking and verifying before this goes any further.

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On 4/26/2019 at 4:00 PM, Crashtd420 said:

Have you verified the piston is truly at tdc on the compression stock vs the zero mark on the pulley?

I have not but ive been driving the truck for years, i removed the Dizzy cap and marked where the rotor was and made sure it went back right where it was when i put the Lseries shaft in 

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On 4/27/2019 at 11:59 AM, Stoffregen Motorsports said:

You had the cam gear off in the past?

 

Your timing at idle shows 30 degrees and runs great?

 

The oil pump spindle may be a tooth off?

 

Time to get back to ground zero.

- Start with verifying TDC (screwdriver down #1 spark plug hole, then check the mark at the pulley).

- Then check the clocking of the oil pump/distributor drive spindle (the dots line up before you stab it home).

- Check your cam timing (with various methods. I like the split overlap method, but it does require a dial indicator like this - https://www.harborfreight.com/clamping-dial-indicator-63656.html?cid=paid_google|*PLA+-+All+Products|All+Products|63656&utm_source=google&utm_medium=cpc&mkwid=sKE0GgBvZ|pcrid|327822404853|pkw||pmt||pdv|c|slid||product|63656|&pgrid=71439424048&ptaid=pla-296227499965&pcid=1688396772&gclid=EAIaIQobChMI8bDD2tHw4QIVoRx9Ch2qhgjVEAYYAiABEgJcJfD_BwE

- Now you can fire it off and check ignition timing.

Cam gear was never off

yes timing shos 30*

Originally i believed it to be off 1 tooth retarded

 

I have the factory assembly manual and ive been through many of these motors and have never used a timing light before .. all been by ear

They either run or they dont with the factory fuel injection but as i have read the carbs may need additional timing.. just seems strage its at 30...

 

Maybe the crank pulley walked on the rubber insulator over time? im not sure 

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On 4/27/2019 at 12:09 PM, datzenmike said:

The pump being off a tooth or more will place the distributor in a position where you can't turn it enough to get the proper timing. Then it will need to be clocked into range

 

30 BTDC is insanely advanced, I would even say impossibly advanced. So assuming this is not possible to run, then either the timing light is set or read wrong, the timing scale is wrong or crank pulley is marked wrong.

 

My dizzy is on a set screw and i can turn it 360* 

Gun could be bad but its brand new (still though could be incorrect) 

It has an advanced setting where i can set it in 1* increments and if i set it to 25ish and let it idle its at the 0* mark on the crank

This leads me to believe it is working properly 

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30 is what I would think about 3 X what it should be. How can it idle at this amount?

 

Is the mark on the crankshaft pulley correct??? Is there one somewhere closer to 0???

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50 minutes ago, datzenmike said:

30 is what I would think about 3 X what it should be. How can it idle at this amount?

 

Is the mark on the crankshaft pulley correct??? Is there one somewhere closer to 0???

I have tried to tune this thing with the timing marks all over the board.. I can dial this thing back to 3* like the book calls for for F.I and itll run just the same but pops and clicks and carrys on through the intake 

 

Where i have it currently is where it runs the best 

 

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On 4/26/2019 at 7:34 AM, alexg89 said:

I thought about this

 

When i did my timing chain a few years back i may have had it 1 tooth off .. had to have it advanced all the way for it to run correctly .. you may be on to something here 

 

Now you're saying that you never had the cam gear off? You are giving us conflicting info.

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1 hour ago, Stoffregen Motorsports said:

Now you're saying that you never had the cam gear off? You are giving us conflicting info.

 

When you do the timing chain on these you have to remove the oil pump and shaft that goes to the distributor 

 

When i put the shaft back in it was off 1 tooth at the crank. .thus being the dizzy had to be cranked fully advanced for it to be correct 

 

Cam gear was not replaced just chain, guides and tensioners  

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Ok, well I guess I need to clarify. What I meant to say was that the chain was removed and the position between the cam and crank could now be off. Unless you are positive that the cam timing is correct, I suggest you verify it before you go any further. The combined symptoms that you have given us are confusing, and when things get confusing, it's time to get back to square one.

 

Verify TDC.

Verify cam timing.

Verify distributor drive spindle.

If any of these are found to be off, make your changes and start tuning all over again.

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Well i can say where its at right now it runs great

Not sure what could be off unless the crank pulley spun on the rubber insulator but i got my top pull throttle linkage in and it runs just fine

Pulls pretty hard from 3800ish all the way to 7k 

 

Im sure if anything was off it woudnt do such.

 

I am how ever having an issue when trying to cruise in 4th or 5th at about 40ish .. wants to buck a little bit.. im guessing this has to do with the "tuning " still  

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I have no doubt this combo will rev past 7K. Unless you have stronger after market rods the 'red line' for a 96mm stroke engine is just under 6500RPMs. A quick buss above this is probably ok but sustained in higher gears should be avoided. The acceleration / deceleration g forces at these piston speeds is nearing the metallurgical limits of the rods and cap bolts. The red line is the upper limit that an engine can safely rev constantly at full throttle, assuming all components are perfect and there is proper oil and temperature control. The formula is rod stroke (in inches) X RPM / 6 = > 4,000. 

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2 minutes ago, datzenmike said:

I have no doubt this combo will rev past 7K. Unless you have stronger after market rods the 'red line' for a 96mm stroke engine is just under 6500RPMs. A quick buss above this is probably ok but sustained in higher gears should be avoided. The acceleration / deceleration g forces at these piston speeds is nearing the metallurgical limits of the rods and cap bolts. The red line is the upper limit that an engine can safely rev constantly at full throttle, assuming all components are perfect and there is proper oil and temperature control. The formula is rod stroke (in inches) X RPM / 6 = > 4,000. 

Was not aware of this, i will dial the rev limiter back down lol 

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It's a good sign when you actually have to dial it back. 😄

 

 

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I'm still not convinced. Ignoring the facts can lead to disaster. 30 degrees of timing at idle...that's a huge fact that I would investigate further, which is why I say it's time to get back to a baseline of established facts. It's your call, but I would check things off the list before I drove it any more.

 

As far as redline goes, even the best 310 hp 12 valve KA24 race engines that I was building back in the late 90's only made power to about 7200 rpms. After that, they would break the snout off the crank, or the bearings would fail. We were using L series rod bearings in them back then because they were wider, but even with all the oiling system mods, they just wouldn't hold up. We also fully counterweighted and knife edged the cranks, used Carrillo rods, dry sump pumps and custom Fluid Damper harmonic balancers, 0-ringed the blocks, built custom dual row timing chain setups, modified the rockers to delete the hydraulic adjusters with threaded "elephant's foot" adjuster, etc. There were many mods that needed to be made just in the name of stability. Even with all these mods, the motors only lasted about 4 races.

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13 minutes ago, Stoffregen Motorsports said:

I'm still not convinced. Ignoring the facts can lead to disaster. 30 degrees of timing at idle...that's a huge fact that I would investigate further, which is why I say it's time to get back to a baseline of established facts. It's your call, but I would check things off the list before I drove it any more.

 

As far as redline goes, even the best 310 hp 12 valve KA24 race engines that I was building back in the late 90's only made power to about 7200 rpms. After that, they would break the snout off the crank, or the bearings would fail. We were using L series rod bearings in them back then because they were wider, but even with all the oiling system mods, they just wouldn't hold up. We also fully counterweighted and knife edged the cranks, used Carrillo rods, dry sump pumps and custom Fluid Damper harmonic balancers, 0-ringed the blocks, built custom dual row timing chain setups, modified the rockers to delete the hydraulic adjusters with threaded "elephant's foot" adjuster, etc. There were many mods that needed to be made just in the name of stability. Even with all these mods, the motors only lasted about 4 races.

 

I wish i had your knowledge and knew how to do these things.

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And for the ones that mentioned my rats nest of wiring early on  i started to try and hide it lol 

jvbwXPg.jpg

 

Edited by alexg89

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So last night i was driving the truck around town.. and i noticed it was starting to idle low and get sluggish

 

The idle screw and the screw thats in the center to adjust the Sync had backed out a little.. Would it be okay to put a dab of blue lock-tight on them?

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Loctite isn't  a bad idea for the screw in the linkage, but I wouldn't use any on the screws that go into the aluminum carb body.

 

Don't they have springs already? I have never had that problem.

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5 minutes ago, Stoffregen Motorsports said:

Don't they have springs already? I have never had that problem.

They do have springs but for some reason they backed out.. and i was gonna use blue.. i use it on all my rc car stuff and its not to harsh like the red 

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You should only be using two idle screws. One in the linkage and one in the one carb body. Is this what you have?

 

One other thing I thought of, have you set your throttle stop at the pedal? If you have not, and the pedal out-travels the throttle shaft, you could twist the throttle shafts. Just thought I'd mention it.

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20 minutes ago, Stoffregen Motorsports said:

You should only be using two idle screws. One in the linkage and one in the one carb body. Is this what you have?

 

One other thing I thought of, have you set your throttle stop at the pedal? If you have not, and the pedal out-travels the throttle shaft, you could twist the throttle shafts. Just thought I'd mention it.

 

Im only using the one in the carb body... not aware of another one ?

 

And as a pedal stop.. i have not looked into that yet 

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Alright so i got the header on.. It had that big dumb ball socket on it and i hacked it off so it wasnt 2in anymore .. 


it goes 2.5 back for about 3 feet down to 2.25 back and sounds pretty good


Ive been looking around for cams and was curious if anyone has any insight on them?

 

also Stoffregen Motorsports i backed the timing down to about 20* and its having smoother transitions and dosnt seem to break up from 1k-2k rpms

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