Heading into the home stretch!! - ZR-1 Net Registry Forums

Paul Workman · 06-20-2010

It seems like "forever" since Lee and I pulled my hurt LT5 from the engine bay. The car will have been on jacks for 10 months, come June 30th.

Started out with what turned out to be a "melted" valve; according to the skilled eye of the machinist grinding the valves and seats.

Well, as long as the heads were off anyway, might as well port them, right? And, with a shining example (Pete's heads) to go by, might as well push the limit, huh? But, as Mark Haibeck once told me, "85% of the risk is in the last 15% of the porting!" How very true, it turns out. Welding a booboo on these heads takes a very skilled welder with the right equipment and rods. I feel I learned a great deal about porting these heads, but if I had it to do over, I'd think hard about just having them CNC'd by Pete's guy and be done with it.

However, it hasn't been all frustration. In the end I was able to incorporate nuance nuggets from Marc Haibeck's approach as well as Pete's on both the porting, the bowels, and relieving.

Anywayz...The last bit was to seal up a pin-hole in a weld in the lifter side of the runner. (Held 21" of Hg for over 15 minutes and never lost a bit!) Now both heads are sporting a very nice multi-angled valve job, been relieved, and milled. Time to put it back together!!

Some pix "along the way"...

It shouldn't be long now!

P.

06-20-2010	#1
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Heading into the home stretch!! It seems like "forever" since Lee and I pulled my hurt LT5 from the engine bay. The car will have been on jacks for 10 months, come June 30th. Started out with what turned out to be a "melted" valve; according to the skilled eye of the machinist grinding the valves and seats. Well, as long as the heads were off anyway, might as well port them, right? And, with a shining example (Pete's heads) to go by, might as well push the limit, huh? But, as Mark Haibeck once told me, "85% of the risk is in the last 15% of the porting!" How very true, it turns out. Welding a booboo on these heads takes a very skilled welder with the right equipment and rods. I feel I learned a great deal about porting these heads, but if I had it to do over, I'd think hard about just having them CNC'd by Pete's guy and be done with it. However, it hasn't been all frustration. In the end I was able to incorporate nuance nuggets from Marc Haibeck's approach as well as Pete's on both the porting, the bowels, and relieving. Anywayz...The last bit was to seal up a pin-hole in a weld in the lifter side of the runner. (Held 21" of Hg for over 15 minutes and never lost a bit!) Now both heads are sporting a very nice multi-angled valve job, been relieved, and milled. Time to put it back together!! Some pix "along the way"... It shouldn't be long now! P. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry Last edited by Paul Workman; 06-20-2010 at 12:22 AM.