1997 gmc k2500 burban

Christian Steffen

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Power Steering hoses and decided on timing chain/water pump. Trying to check for slack looked like about 10* before pulling things apart. Loosening the oil pan is a major pain. With new timing set 2* of slack movement. New timing set is a couple of degrees different from the original.
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I commend you for doing a timing chain with the engine in.. that looks like a PITA! So you did end up replacing the timing set then? IIRC the retard was all in the gear? Just checking because i can't remember for sure lol

Also, maybe i missed it but what are the plans for the 489?
 

yevgenievich

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I commend you for doing a timing chain with the engine in.. that looks like a PITA! So you did end up replacing the timing set then? IIRC the retard was all in the gear? Just checking because i can't remember for sure lol

Also, maybe i missed it but what are the plans for the 489?
Initially I thought stock replacement timing set would be same as gm, but it appears the cam gear is 6* or 8* different from stock. Hoping it will run better on the road. Other motor is in the machine shop taking more time than it should. Waiting on piston selection confirmation so I can order heads(brodix race rite oval ports) and this is current proposed cam spec:

233/233 @.050"
.353"/.353" Lobe Lift
.600"/.600" Valve Lift
114 LSA

Specific cam core I was looking for is expected to be available in September
 

yevgenievich

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Initially worked well, even had the crank retard thing in spec. Had to run it very hard today and eventually motor died. Trans also threw input vss and gear ratio codes at me
 

yevgenievich

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A bloody distributor cap. Apparently is more than capable of just fully failing and causing a no spark condition. Had a lot of things going on and just left it alone until this week. An essentially new distributor cap turned out to be at fault. Going to have to carry a spare in the glove box until I get the coil pack set up fitted
 

Christian Steffen

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Initially I thought stock replacement timing set would be same as gm, but it appears the cam gear is 6* or 8* different from stock. Hoping it will run better on the road. Other motor is in the machine shop taking more time than it should. Waiting on piston selection confirmation so I can order heads(brodix race rite oval ports) and this is current proposed cam spec:

233/233 @.050"
.353"/.353" Lobe Lift
.600"/.600" Valve Lift
114 LSA

Specific cam core I was looking for is expected to be available in September
The brodix heads are going to be awesome I'm sure, definitely jealous.

So you've got it back up and running with a new cap? Those can be a real *****. Other thoughts with more time on it?
 

yevgenievich

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The brodix heads are going to be awesome I'm sure, definitely jealous.

So you've got it back up and running with a new cap? Those can be a real *****. Other thoughts with more time on it?
I actually did a lot of unnecessary work and checks before realizing especially new cap was at fault. Change is not major, but first impression after the cam gear install felt a bit more power in the lower rpm range. Towed a 25ft camper trailer today and although speed was around 55mph, it maintained it pretty well in 3rd gear with tcc locked around 2100rpm without a lot of extra throttle input.
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yevgenievich

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Originally decided not to replace the balancer, but should have. New seal was leaking badly likely due to wear spot on the balancer. Had to remove the balancer and install a new seal about 1mm out from original position. Leak stopped.
 

Christian Steffen

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Sounds like it did what it should, glad to hear its running well!
I actually did a lot of unnecessary work and checks before realizing especially new cap was at fault. Change is not major, but first impression after the cam gear install felt a bit more power in the lower rpm range. Towed a 25ft camper trailer today and although speed was around 55mph, it maintained it pretty well in 3rd gear with tcc locked around 2100rpm without a lot of extra throttle input.
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HotWheelsBurban

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Found the cause of sudden poor idle and reduced performance.
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Yup those white rotors would do that to me every 6 months or so. Put a Blue Streak rotor in, and it lasted 2 years,of daily city driving! It wasn't that worn when I changed the cap in April ( for the UMP vented cap. But since I was in there, and I had my spare one I bought in '19, I went ahead and changed it. Now I still have a spare rotor, it's just a little used. And the price difference wasn't that much, especially considering the much longer life expectancy.
I have one of those small metal magnetic parts trays you get at the tool places, and one of the things I use it for is the cap and rotor job. Since for whatever reason, GM didn't have the screws staked into the parts like the old style....the magnet tray and an extendable magnet on a stick are very helpful for not dropping or losing those tiny Torx screws.
 
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