Catching up
Its been a few months since I wrote about the truck so heres an update. The tranny and 208AM got dropped off to be rebuilt. The 208 needed a new chain and apparently the 727 tranny was trashed from the TV link being mis-adjusted(DPO!)
I am running a carb(insert luddite comment here)and so have to make my early manifolds match to the 7120 head. Using a 91 header until I fab my own concoction. With a small trim-the 81 manifold nestled right in.
Here is a shot of the mods I made to the 81 intake to mate to the 7120 head. Another 84 intake shown to compare.
After a week of using the jeep strokers website calculator http://www.jeepstrokers.com/calculator/ I finally decided I need to remove as much chamber material as possible. I started going to town on one chamber and managed to get from 57.5cc to 60cc but I felt the chamber was too thin. That grey stuff was used to seal the chamber to measure the cc.
I went to the wreck yard and grabbed another 7120 head as a backup. After doing more math I decided it wasn’t worth it and was gonna just retard a stock cam to bring my DCR down to streetable. =(( I grabbed my redneck valvespring compressor and went to work tearing down the head.
I did some minor chamber smoothing and tried to clean things up a little. Acting on my machinists advice, I took care of the ridges around the valve seat and blended a teardrop shape into the valvestem area. I left the intake port alone to keep the air turbulent and keep the fuel suspended. I did a mild polish on the exhaust port. I could have taken more material but I not only didn’t want to take the time-I didn’t want to accidentally hit water due to a possible core shift. This head got dropped at the machinist to get new stainless valves, beehive springs and a nice custom valve job.
I started mocking up my accessories to get a feel of where I am going to mount my York compressor for my onboard air.
I am running a carb(insert luddite comment here)and so have to make my early manifolds match to the 7120 head. Using a 91 header until I fab my own concoction. With a small trim-the 81 manifold nestled right in.
Here is a shot of the mods I made to the 81 intake to mate to the 7120 head. Another 84 intake shown to compare.
After a week of using the jeep strokers website calculator http://www.jeepstrokers.com/calculator/ I finally decided I need to remove as much chamber material as possible. I started going to town on one chamber and managed to get from 57.5cc to 60cc but I felt the chamber was too thin. That grey stuff was used to seal the chamber to measure the cc.
I went to the wreck yard and grabbed another 7120 head as a backup. After doing more math I decided it wasn’t worth it and was gonna just retard a stock cam to bring my DCR down to streetable. =(( I grabbed my redneck valvespring compressor and went to work tearing down the head.
I did some minor chamber smoothing and tried to clean things up a little. Acting on my machinists advice, I took care of the ridges around the valve seat and blended a teardrop shape into the valvestem area. I left the intake port alone to keep the air turbulent and keep the fuel suspended. I did a mild polish on the exhaust port. I could have taken more material but I not only didn’t want to take the time-I didn’t want to accidentally hit water due to a possible core shift. This head got dropped at the machinist to get new stainless valves, beehive springs and a nice custom valve job.
I started mocking up my accessories to get a feel of where I am going to mount my York compressor for my onboard air.
posted by ccpanel at 9:10 PM
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