Need help with spec diagnostics
07-11-2013, 03:07 PM
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Need help with spec diagnostics Hey guys, first thing, I had to create a new account, I'm really not totally new to the forum. 
Onward to the post!
I have a built LQ9 from texas speed that I am putting back together after a maggie intercooler broke and caused some serious headache.
I am putting together the valve train right now and I need some help figuring out tolerances and whether or not anything is going to break.
The old setup that worked flawlessly on my LS1: ported 241 heads, crane gold 1.8 rockers, crane pushrods (7.25 I believe), crane dual valve springs (titanium retainers, etc), crane hydraulic roller lifters (stock replacement), MTI Stealth 2 cam (224/220 .581/.581 116 LSA).
The new setup: all same parts as above, just moved onto 317 heads.
Problem that occurred recently: Recently, I had put stock rockers and stock pushrods on the 317 heads. Everything else stayed the same. The car did not like that combo, 1 push rod bent, 1 rocker arm bearing broke and 1 lifter top collapsed. Obviously something went wrong... the only big difference I could see was the stock push rods were noticeably longer than the hardened cam pushrods that came with the 1.8 rockers.
Question: Was the breaking of the stock parts some freak incident or were the tolerances so far off it caused a break. Should I be worried about using the 1.8 rockers and 7.25 pushrods on the 317 heads with a stealth II cam? Do I need to change the pushrod length?
Thanks a ton guys, there is a wealth of knowledge here, hoping someone can point me in the right direction.
Onward to the post!
I have a built LQ9 from texas speed that I am putting back together after a maggie intercooler broke and caused some serious headache.
I am putting together the valve train right now and I need some help figuring out tolerances and whether or not anything is going to break.
The old setup that worked flawlessly on my LS1: ported 241 heads, crane gold 1.8 rockers, crane pushrods (7.25 I believe), crane dual valve springs (titanium retainers, etc), crane hydraulic roller lifters (stock replacement), MTI Stealth 2 cam (224/220 .581/.581 116 LSA).
The new setup: all same parts as above, just moved onto 317 heads.
Problem that occurred recently: Recently, I had put stock rockers and stock pushrods on the 317 heads. Everything else stayed the same. The car did not like that combo, 1 push rod bent, 1 rocker arm bearing broke and 1 lifter top collapsed. Obviously something went wrong... the only big difference I could see was the stock push rods were noticeably longer than the hardened cam pushrods that came with the 1.8 rockers.
Why I used stock parts: While in the midst of moving garages, I was waiting on parts that had not arrived, so I was forced to put together a 'stock' head/valve train in order to get the car up and moved.
I had the parts so it wasn't a big deal at the time.
I had the parts so it wasn't a big deal at the time.
Question: Was the breaking of the stock parts some freak incident or were the tolerances so far off it caused a break. Should I be worried about using the 1.8 rockers and 7.25 pushrods on the 317 heads with a stealth II cam? Do I need to change the pushrod length?
Thanks a ton guys, there is a wealth of knowledge here, hoping someone can point me in the right direction.
