Just purchased used 383 splayed main forged lt1, any tips to check over?
03-15-2024, 11:04 AM
#61
Race Director
Thread Starter
I have 4.125 size with valve pockets Cometic gaskets with 210 AFR heads (383 boosted with D1). The part number is H2430SP10xxS. The xx is the thickness 50, 70, or whatever.
Anything smaller will be exposed in the cylinder increasing the compression ratio. My 1st engine had the wrong size and it had burn marks on it. That engine blew up from that and other issues
.
Anything smaller will be exposed in the cylinder increasing the compression ratio. My 1st engine had the wrong size and it had burn marks on it. That engine blew up from that and other issues
.The guy said he wasnt aware that there was a difference between head gaskets between the 2 (SBC and LT1) and acted like it would work on my Lt1.
I thought the head gaskets are different (SBC vs. LT1) due to reverse cooling?
someone correct me if im wrong
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STEVEN13 (03-15-2024)
03-22-2024, 08:01 AM
#66
Race Director
Thread Starter
UPDATE:
had issues with pistons contacting the intake valve. No damage done, bc i was hand turning the crank. However it has me spooked.
My new solid lifters are .75” shorter than the ls7 hydraulic lifters (i had in there), so logic told me i need a .75” longer pushrod. So i set my adjustable length pushrod to .75” longer and that was the result
also usjng shaft mount rockers
i sent engine back to the shop to have them finish the top end since i apparently dont know what im doing
Last edited by dizwiz24; 03-23-2024 at 08:49 AM.
03-23-2024, 09:15 AM
#69
ive already got one and thats what will be going on it
UPDATE:
had issues with pistons contacting the intake valve. No damage done, bc i was hand turning the crank. However it has me spooked.
My new solid lifters are .75” shorter than the ls7 hydraulic lifters (i had in there), so logic told me i need a .75” longer pushrod. So i set my adjustable length pushrod to .75” longer and that was the result
also usjng shaft mount rockers
i sent engine back to the shop to have them finish the top end since i apparently dont know what im doing
UPDATE:
had issues with pistons contacting the intake valve. No damage done, bc i was hand turning the crank. However it has me spooked.
My new solid lifters are .75” shorter than the ls7 hydraulic lifters (i had in there), so logic told me i need a .75” longer pushrod. So i set my adjustable length pushrod to .75” longer and that was the result
also usjng shaft mount rockers
i sent engine back to the shop to have them finish the top end since i apparently dont know what im doing
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AmoriFati (03-23-2024)
03-23-2024, 05:08 PM
#71
I may be wrong, but since it is shorter by that amount, I think there is a different length, not exactly .750 due to it being a ratio at the rocker. You set it at the base of cam regardless, then the length of the pushrod is needed just to get full lift at the tip of the rocker. Thats why you use an adjustable pushrod for verifying length needed.
I am speaking out loud, not to you, just confirming if that is what you do.
I am speaking out loud, not to you, just confirming if that is what you do.
03-23-2024, 07:44 PM
#72
Safety Car
Because you have shaft rockers the pushrods would have needed to be quite a bit shorter.... the adjuster cup sticks way further down than typical stud mount rocker.
Also you should have figured out your rocker geometry with the head on a work bench.... a great advantage of shaft rockers is that the stand height determines the rocker geometry. It's a very simple and quick setup to see where you need to be. The little tool they send gets you very close and from there it's easy to fine tune if needed... you can even (using checking springs) and a dial indicator push the valves down to max lift to verify your rocker is rolling out and then back towards the intake face at max lift and like I said, fine tune it until you get the narrowest possible sweep.
The pushrods on a solid lifter with shaft rocker setup is likewise very simple. You put the lifter in, rotate the cam until it's on the basecircle, put the head on with the rockers bolted down, adjust the rocker adjuster down 1 turn from fully seated and stick an adjustable pushrod in there (completely closed)... lengthen the adjustable pushrod until it just makes contact with the seats of the rocker adjuster and lifter.... Unbolt the rockers, pull the pushrod out and measure it.
Unless you have checking springs on the head, you should not be checking piston to valve with an adjustable pushrod.... mechanical roller springs with easily bend or flex it so much it'll be damaged or give a false reading. You really shouldn't do it even with checking springs but I do occasionally when I don't already have a correct length pushrod at my disposal.
I know you already sent it to someone else but maybe this will help someone else in the future.
Will
Also you should have figured out your rocker geometry with the head on a work bench.... a great advantage of shaft rockers is that the stand height determines the rocker geometry. It's a very simple and quick setup to see where you need to be. The little tool they send gets you very close and from there it's easy to fine tune if needed... you can even (using checking springs) and a dial indicator push the valves down to max lift to verify your rocker is rolling out and then back towards the intake face at max lift and like I said, fine tune it until you get the narrowest possible sweep.
The pushrods on a solid lifter with shaft rocker setup is likewise very simple. You put the lifter in, rotate the cam until it's on the basecircle, put the head on with the rockers bolted down, adjust the rocker adjuster down 1 turn from fully seated and stick an adjustable pushrod in there (completely closed)... lengthen the adjustable pushrod until it just makes contact with the seats of the rocker adjuster and lifter.... Unbolt the rockers, pull the pushrod out and measure it.
Unless you have checking springs on the head, you should not be checking piston to valve with an adjustable pushrod.... mechanical roller springs with easily bend or flex it so much it'll be damaged or give a false reading. You really shouldn't do it even with checking springs but I do occasionally when I don't already have a correct length pushrod at my disposal.
I know you already sent it to someone else but maybe this will help someone else in the future.
Will
03-23-2024, 07:54 PM
#73
Race Director
Thread Starter
Because you have shaft rockers the pushrods would have needed to be quite a bit shorter.... the adjuster cup sticks way further down than typical stud mount rocker.
Also you should have figured out your rocker geometry with the head on a work bench.... a great advantage of shaft rockers is that the stand height determines the rocker geometry. It's a very simple and quick setup to see where you need to be. The little tool they send gets you very close and from there it's easy to fine tune if needed... you can even (using checking springs) and a dial indicator push the valves down to max lift to verify your rocker is rolling out and then back towards the intake face at max lift and like I said, fine tune it until you get the narrowest possible sweep.
The pushrods on a solid lifter with shaft rocker setup is likewise very simple. You put the lifter in, rotate the cam until it's on the basecircle, put the head on with the rockers bolted down, adjust the rocker adjuster down 1 turn from fully seated and stick an adjustable pushrod in there (completely closed)... lengthen the adjustable pushrod until it just makes contact with the seats of the rocker adjuster and lifter.... Unbolt the rockers, pull the pushrod out and measure it.
Unless you have checking springs on the head, you should not be checking piston to valve with an adjustable pushrod.... mechanical roller springs with easily bend or flex it so much it'll be damaged or give a false reading. You really shouldn't do it even with checking springs but I do occasionally when I don't already have a correct length pushrod at my disposal.
I know you already sent it to someone else but maybe this will help someone else in the future.
Will
Also you should have figured out your rocker geometry with the head on a work bench.... a great advantage of shaft rockers is that the stand height determines the rocker geometry. It's a very simple and quick setup to see where you need to be. The little tool they send gets you very close and from there it's easy to fine tune if needed... you can even (using checking springs) and a dial indicator push the valves down to max lift to verify your rocker is rolling out and then back towards the intake face at max lift and like I said, fine tune it until you get the narrowest possible sweep.
The pushrods on a solid lifter with shaft rocker setup is likewise very simple. You put the lifter in, rotate the cam until it's on the basecircle, put the head on with the rockers bolted down, adjust the rocker adjuster down 1 turn from fully seated and stick an adjustable pushrod in there (completely closed)... lengthen the adjustable pushrod until it just makes contact with the seats of the rocker adjuster and lifter.... Unbolt the rockers, pull the pushrod out and measure it.
Unless you have checking springs on the head, you should not be checking piston to valve with an adjustable pushrod.... mechanical roller springs with easily bend or flex it so much it'll be damaged or give a false reading. You really shouldn't do it even with checking springs but I do occasionally when I don't already have a correct length pushrod at my disposal.
I know you already sent it to someone else but maybe this will help someone else in the future.
Will
yeah i had the shop the built the bottom end install checker springs before attempting the ill-fated measurement
ive set them up before (determined pushrod length) on my old hydraulic roller setup and it ran great
whats messing me up is i have 2 new variables to deal with that will affect pushrod length
1. Conversion of hydraulic to solid roller cam (and the shorter solid lifters
2. Jesel shaft mount rockers - which are something im unfamiliar with
other problems with the shaft mount rockers included
1. The head bolts they supply (that has a flat head that sits below the stand) dont bottom out. They either need shortened, or a washer? installes under the head
2. the center of the tips of jesel
shaft rocker arms arent centered over the center of each valve stem. It like the whole stand is 1-2mm too far rearward on those heads (afr210 comp elim)
given all the issues, i took it back to them to let them sort it out. Im sure they will charge me plenty for that
03-23-2024, 08:07 PM
#74
Safety Car
yeah i had the shop the built the bottom end install checker springs before attempting the ill-fated measurement
ive set them up before (determined pushrod length) on my old hydraulic roller setup and it ran great
whats messing me up is i have 2 new variables to deal with that will affect pushrod length
1. Conversion of hydraulic to solid roller cam (and the shorter solid lifters
2. Jesel shaft mount rockers - which are something im unfamiliar with
other problems with the shaft mount rockers included
1. The head bolts they supply (that has a flat head that sits below the stand) dont bottom out. They either need shortened, or a washer? installes under the head
2. the center of the tips of jesel
shaft rocker arms arent centered over the center of each valve stem. It like the whole stand is 1-2mm too far rearward on those heads (afr210 comp elim)
given all the issues, i took it back to them to let them sort it out. Im sure they will charge me plenty for that
ive set them up before (determined pushrod length) on my old hydraulic roller setup and it ran great
whats messing me up is i have 2 new variables to deal with that will affect pushrod length
1. Conversion of hydraulic to solid roller cam (and the shorter solid lifters
2. Jesel shaft mount rockers - which are something im unfamiliar with
other problems with the shaft mount rockers included
1. The head bolts they supply (that has a flat head that sits below the stand) dont bottom out. They either need shortened, or a washer? installes under the head
2. the center of the tips of jesel
shaft rocker arms arent centered over the center of each valve stem. It like the whole stand is 1-2mm too far rearward on those heads (afr210 comp elim)
given all the issues, i took it back to them to let them sort it out. Im sure they will charge me plenty for that
So contrary to internet lore, it's not imperative that the roller be centered on the valve tip... as long as it's in the center 3rd of the valve tip throughout its lift cycle, you are fine. And you have to understand that with proper geometry, the roller will move from the intake face side of the tip across towards the exhaust face side... It then moves back towards the intake face side a 1/4 way to near max lift.... Jesel uses a geometry system where the rocker moves across the valve the most during low lift and lower valve spring pressure.....
Will