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Today I checked all the lifters and they're set with zero gap. I can wiggle the rocker arm but can't get anything under it, not even .001. Are they set correctly?
Bubba honked up a few things like the wiring so didn't want to trust he got the right spark plugs. I replaced his Autolite AP24 with NGK 7052, seems to run alright.
I have this question submitted to Summit since they sell a similar head but haven't received a response yet. Hopefully tomorrow.
If you checked at least one cylinder when it was at TDC on compression stroke and had zero clearance then you have hydraulics.
How did you end up with NGK 7052 it is a non-projected tip plug. Below are the plugs for a Gen V Big Block with a .460 reach and tapered seats, projected tip. https://www.summitracing.com/search/...00395%2B400721
If you checked at least one cylinder when it was at TDC on compression stroke and had zero clearance then you have hydraulics.
How did you end up with NGK 7052 it is a non-projected tip plug. Below are the plugs for a Gen V Big Block with a .460 reach and tapered seats, projected tip. https://www.summitracing.com/search/...00395%2B400721
To tell you the truth, I don't know. I thought it was a cross ref. To the Autolite but not. The Autolite wasn't a projected tip either. I knew I had the wrong one.
I should be able to buy the AC Delco 19307138 from O'Reilly. Do you know what the part # is?
Easy to set the rocker arm. First you need to re-install the rocker stud in the head, and hope the threads aren't buggered. ARP can give you torque specs.
Once the rocker stud is in, you can reinstall the pushrod and rocker arm.
Its best to rotate the engine until that lifter is on the cam base circle. (When both valves on that cylinder are closed), Tighten the rocker arm nut until the pushrod doesn't wiggle, and another 1/2 turn, then lock it in place. That's close enough to get it running again.
Without taking a head off, you wont know what the piston size /style is.
You can get cam specs from the front of the cam by removing the timing cover, but that's a bigger job.
It may be worth checking al of the rocker studs for proper torque.
Got the cover off and I see one reason why it's missing and not getting any power, one of the rocker arms was so loose I could unscrew it with my fingers. It doesn't appear much damage occurred so I'm thinking about cleaning the threads and reinstalling with lock tight(red or blue?) Also, I don't understand how these are adjusted. I assume these are hydraulic lifters but see no means to adjust. And what torque value do I use when I reinstall the bolt?
The casting # is 12363401, again, what spark plug?
Those are GM Performance heads. 315 cc rectangular port with 118cc chambers. Made by Edelbrock. Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4" reach with flat gasket seat.
I'd use a relatively hot plug like listed with an extended tip for the street.
You've got other issues in the setup. Those appear to be similar rockers to the old Cam Dynamics/Crane Energizer versions. I've used them in the past and they aren't fancy but will do just fine for what you're doing. But look closely at the lock nuts. They are too short and rubbing on the rockers. The rockers will eventually unscrew them or the stud as you found. You need some different adjusters and/or go over the pushrod length/rocker geometry closely to make sure things are correct. My gut tells me there's some work to be done there.
You certainly need to change that rocker and pushrod...they are FUBAR.
You've got some real nice parts...just some poor assembly. As others have mentioned it's a 4.250" stroke (.250" longer than a 454) with 6.385" rods (.250" longer than stock) and good SRP pistons made of 4032 material. It could be a 489 or a 496 depending on bore size. I see an external balanced type balancer on it...so that means the flywheel should also be external balanced. The heads flow around 315 CFM so they are capable of 600+ HP easily. Without knowing which pistons are in it for sure I can't tell compression, but likely they have small domes and you're just under 10.0..maybe 9.8 compression ratio. Cam....you'll need to do some measuring with a degree wheel to figure that one out a little closer.
Those are GM Performance heads. 315 cc rectangular port with 118cc chambers. Made by Edelbrock. Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4" reach with flat gasket seat.
I'd use a relatively hot plug like listed with an extended tip for the street.
You've got other issues in the setup. Those appear to be similar rockers to the old Cam Dynamics/Crane Energizer versions. I've used them in the past and they aren't fancy but will do just fine for what you're doing. But look closely at the lock nuts. They are too short and rubbing on the rockers. The rockers will eventually unscrew them or the stud as you found. You need some different adjusters and/or go over the pushrod length/rocker geometry closely to make sure things are correct. My gut tells me there's some work to be done there.
You certainly need to change that rocker and pushrod...they are FUBAR.
You've got some real nice parts...just some poor assembly. As others have mentioned it's a 4.250" stroke (.250" longer than a 454) with 6.385" rods (.250" longer than stock) and good SRP pistons made of 4032 material. It could be a 489 or a 496 depending on bore size. I see an external balanced type balancer on it...so that means the flywheel should also be external balanced. The heads flow around 315 CFM so they are capable of 600+ HP easily. Without knowing which pistons are in it for sure I can't tell compression, but likely they have small domes and you're just under 10.0..maybe 9.8 compression ratio. Cam....you'll need to do some measuring with a degree wheel to figure that one out a little closer.
JIM
Thanks a bunch for this info, exactly what I was looking for. Yes, good point, I think the rockers need some work.
In regards to the flywheel, aren't all flywheels balanced before you buy them?
Flywheels are either intended for an internally balanced engine or an externally balanced one. An external balanced one will have additional weights or casting bosses on them. Usually used with a harmonic balancer with the same feature. It's usually done so they can use the same basic casting/forging for the crank even though the stroke got longer. In other words it's cheaper. Instead of making larger counterweights or adding additional ones...they just add weight to the ends of the assy at the balancer and flywheel. Works OK in most applications...but as you get into more HP and RPM you prefer to have it internally balanced with the correct weight where it truly belongs. Adding it to the end creates some bending motion in the crank as RPM increases. 454's and 502's were externally balanced from the factory. Some later 350's are a mixture. Super Cobra Jets and 440 six packs used an extra balancer weight to account for the heavier rods. Small block fords have external weights.
Anyway, you just have to know how your engine was balanced and it appears you have an external balanced balancer on it so I assume there's an external balanced flywheel also. The alternative is to drill the counterweights and add heavy "Mallory" metal which is very expensive to purchase and install. A buddy spent $1200 to balance his 632" crank if that gives you an idea!
Flywheels are either intended for an internally balanced engine or an externally balanced one. An external balanced one will have additional weights or casting bosses on them. Usually used with a harmonic balancer with the same feature. It's usually done so they can use the same basic casting/forging for the crank even though the stroke got longer. In other words it's cheaper. Instead of making larger counterweights or adding additional ones...they just add weight to the ends of the assy at the balancer and flywheel. Works OK in most applications...but as you get into more HP and RPM you prefer to have it internally balanced with the correct weight where it truly belongs. Adding it to the end creates some bending motion in the crank as RPM increases. 454's and 502's were externally balanced from the factory. Some later 350's are a mixture. Super Cobra Jets and 440 six packs used an extra balancer weight to account for the heavier rods. Small block fords have external weights.
Anyway, you just have to know how your engine was balanced and it appears you have an external balanced balancer on it so I assume there's an external balanced flywheel also. The alternative is to drill the counterweights and add heavy "Mallory" metal which is very expensive to purchase and install. A buddy spent $1200 to balance his 632" crank if that gives you an idea!
JIM
I guess my next question is, who does this and can it be done in the car?
It's done while the engine is being built. Nothing you're going to do now and if it's running well without vibrations it's likely been done Ok anyway (external balanced).
I can see a lot of drilling on the rear counterweight in one pic that was done during the build (not crank factory) so someone went through the process to balance it. They used external weight to "add" enough (balancer and flywheel) and then removed it where necessary to bring it into balance. An internal balance job would be done without the flywheel or balancer in place usually (but they could be).
Wow, it looks like someone threw more money than plan at that engine.
The polylocks on those rockers are the the wrong ones. Given your observations of loose rocker studs, I would start by removing all rocker arms/locks and toss them, then inspect all the studs for wear and damage. Assuming they are fine, the studs should be 7/16-14 (coarse thread) where they screw into the head and 7/16-20 (fine thread) rocker adjuster end. Measure them and verify. If so, they are typically torqued to 45 ft/lbs using a thread lube or sealant if the thread boss is open. You need to verify your stud and the correct torque (another option is to remove them all and replace with ARP studs). When reinstalled they screw through the guide plates to hold them in place.
Here’s the first hurdle, while I think your engine is salvageable, I’m not convinced the rocker geometry is correct, meaning the length of the push rod vs. the valve height vs. the rocker stud length may not be matched which probably caused your problem from the beginning. Checking valve geometry and choosing the correct components is not hard, but it has to be done correctly. Based on your comments and questions, and I mean no offense, I would take it to a capable mechanic and have them set up your valve train correctly. I believe there is a high probability of success if this is addressed properly. Best of luck!
Wow, it looks like someone threw more money than plan at that engine.
The polylocks on those rockers are the the wrong ones. Given your observations of loose rocker studs, I would start by removing all rocker arms/locks and toss them, then inspect all the studs for wear and damage. Assuming they are fine, the studs should be 7/16-14 (coarse thread) where they screw into the head and 7/16-20 (fine thread) rocker adjuster end. Measure them and verify. If so, they are typically torqued to 45 ft/lbs using a thread lube or sealant if the thread boss is open. You need to verify your stud and the correct torque (another option is to remove them all and replace with ARP studs). When reinstalled they screw through the guide plates to hold them in place.
Here’s the first hurdle, while I think your engine is salvageable, I’m not convinced the rocker geometry is correct, meaning the length of the push rod vs. the valve height vs. the rocker stud length may not be matched which probably caused your problem from the beginning. Checking valve geometry and choosing the correct components is not hard, but it has to be done correctly. Based on your comments and questions, and I mean no offense, I would take it to a capable mechanic and have them set up your valve train correctly. I believe there is a high probability of success if this is addressed properly. Best of luck!
Sounds like good advice and I appreciate it, just don’t know who to take it to. Need a good reputable engine builder. I’ll ask around, or maybe someone reading this can recommend someone in the Ft. Worth area.
Call these guys in Arlington as a start. They have a complete machine shop and good reviews so someone must know what they are doing. At a minimum, you can explain your issue and ask for a referral.
Call these guys in Arlington as a start. They have a complete machine shop and good reviews so someone must know what they are doing. At a minimum, you can explain your issue and ask for a referral.
Those are GM Performance heads. 315 cc rectangular port with 118cc chambers. Made by Edelbrock. Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4" reach with flat gasket seat.
I'd use a relatively hot plug like listed with an extended tip for the street.
You've got other issues in the setup. Those appear to be similar rockers to the old Cam Dynamics/Crane Energizer versions. I've used them in the past and they aren't fancy but will do just fine for what you're doing. But look closely at the lock nuts. They are too short and rubbing on the rockers. The rockers will eventually unscrew them or the stud as you found. You need some different adjusters and/or go over the pushrod length/rocker geometry closely to make sure things are correct. My gut tells me there's some work to be done there.
You certainly need to change that rocker and pushrod...they are FUBAR.
You've got some real nice parts...just some poor assembly. As others have mentioned it's a 4.250" stroke (.250" longer than a 454) with 6.385" rods (.250" longer than stock) and good SRP pistons made of 4032 material. It could be a 489 or a 496 depending on bore size. I see an external balanced type balancer on it...so that means the flywheel should also be external balanced. The heads flow around 315 CFM so they are capable of 600+ HP easily. Without knowing which pistons are in it for sure I can't tell compression, but likely they have small domes and you're just under 10.0..maybe 9.8 compression ratio. Cam....you'll need to do some measuring with a degree wheel to figure that one out a little closer.
JIM
I wonder the reason they’re short is so they don’t interfere with the valve cover. What brand do you think the rockers are? Any idea what lock nuts I need? Summit Racing is just down the street.
09-25-2017, 02:50 PM
Rockers
