| Slant Six Forum https://slantsix.org/forum/ |
|
| Help choosing which cylinder head to use https://slantsix.org/forum/viewtopic.php?t=55668 |
Page 1 of 1 |
| Author: | Sam Powell [ Mon Jun 23, 2014 5:59 am ] |
| Post subject: | Help choosing which cylinder head to use |
I have read all the threads I could dig up including Doug't article. I have three cylinder heads to chose from. Engine to build is mid 80's hydraulic truck engine. If it were not for the fact that I have a nice aluminum Offenhauser valve cover that will not fit the truck engine head, I would not give this much thought. I would keep all original parts together. I also have the original '69 head that came on the factory engine, which had a valve job, new guides and hardened seats installed about 50K miles before the first engine swap. Over-sized valves are going in either one, so new seats are in order either way. It turns out I used the wrong head on the current engine as I used a 65 head which does not have the improved combustion chamber design, so that narrows the choice down to just 2. Is there any reason to stick with the truck head, and thus lose the nice valve cover? Is it lighter? Is it better in any way at all? Is it less prone to leakage of oil? Will it work better with the hydraulic cam and rockers? I know Reed says both are fine in that regard; just throwing it out there. Are there better spark plug choices for one over the other? Is is easier to change plugs with one or the other? Thanks for your thoughts. Sam |
|
| Author: | Reed [ Mon Jun 23, 2014 9:39 am ] |
| Post subject: | |
I would definitely pick the 69 head reworked head. The truck head will be a bit heavier and have the ports for the air injection system. The combustion chamber design will be the same as the 69 head but it will use the smaller plugs so you will no longer be able to pull the lifters without pulling the head. The hydraulic valve train works just as well on the 69 head as it does on the 80s head. Just be sure to take the rearmost rocker shaft bolt into consideration. I have swapped hydraulic valve trains onto mid 70s heads with no problems. For example, the engine in my brother's 83 Dodge van is a 76 225 short block with a 72 198 rebuilt head. It is running a 1983 hydraulic cam and hydraulic valve train. No problems! This might help explain the rear rocker arm shaft bolt issue better: http://www.slantsix.org/forum/viewtopic.php?t=46756 In my mind the 69 head is better for several reasons: (1) uses the larger sparkplug which means you can run the NGK ZFRN entended tip plugs (2) drool tube head which gives better access to the lifter gallery (3) no air injection passages (4) it fits your cool Offy valve cover But you probably know all af this already. |
|
| Author: | Sam Powell [ Mon Jun 23, 2014 1:50 pm ] |
| Post subject: | |
Thanks Reed. I had read your post earlier. That helps. Sam |
|
| Page 1 of 1 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|