Guys,
I have an F4TE 351W roller block. I'm upgrading to a hyd. roller cam and TFS TW 170 heads (58cc).
1) I measured pushrod length for the new cam and came out to 8.05. I can't find out any info on the dish on the hyperutectic piston, but it's pretty cavernous, like maybe -20? I included a pic of the valve spring head with the marker swipe across the center like I've read and watched videos on for determining pushrod length. Does that look good?
2) For the hell of it I clay tested the GT40 heads with 1.7 rockers, .and old standard cam and lifters 491/510 , on the yellow clay and it squished the clay but was well within a safe margin.
3) Next I clay checked the TFS TW's with my new cam (XE274HR) on the green clay. It didn't even leave a mark. Is this because of the improved valve orientation on the TFS heads? I thought with a .555/.565 lift and bigger valves it would at least touch the clay. The cam is installed straight up. I made two solid roller lifters for the test.
Big question is - Do I have a ton of room for PVC or am I doing something wrong? I've done head swaps before but never swapped from standard to roller cam and obviously don't want to have a bad experience when I hit the key. Any thought?
Thanks in advance,
Tim
I have an F4TE 351W roller block. I'm upgrading to a hyd. roller cam and TFS TW 170 heads (58cc).
1) I measured pushrod length for the new cam and came out to 8.05. I can't find out any info on the dish on the hyperutectic piston, but it's pretty cavernous, like maybe -20? I included a pic of the valve spring head with the marker swipe across the center like I've read and watched videos on for determining pushrod length. Does that look good?
2) For the hell of it I clay tested the GT40 heads with 1.7 rockers, .and old standard cam and lifters 491/510 , on the yellow clay and it squished the clay but was well within a safe margin.
3) Next I clay checked the TFS TW's with my new cam (XE274HR) on the green clay. It didn't even leave a mark. Is this because of the improved valve orientation on the TFS heads? I thought with a .555/.565 lift and bigger valves it would at least touch the clay. The cam is installed straight up. I made two solid roller lifters for the test.
Big question is - Do I have a ton of room for PVC or am I doing something wrong? I've done head swaps before but never swapped from standard to roller cam and obviously don't want to have a bad experience when I hit the key. Any thought?
Thanks in advance,
Tim