Down the bumpstick rabbit-hole again... (cam questions)

GrimGreaser

I have three cams in front of me. The one out of my '52 308 motor (306344), one out of the '56 308 w/ hydraulics (309742 - buggered lobe), and one I bought to replace the bad hydraulic one (309472 too). The two 309742 have obviously different lobe profiles, the one out of my '56 has a wider, rounder tip than the one I got to replace it. So, what do I have? In the picture, left to right - '52 (306344), '56 w/ hyd. lifters (309742), and the replacement cam I bought (309742). I'll get measurements tomorrow, don't have 'em with me.

GrimGreaser

Yeah, I'm aware of the multiple grinds on the 309742 blanks. Are both of mine hydraulic, or is one a mechanical grind?

[Deleted User]

GRIMGREASER, THE CAM I SOLD YOU WAS OUT OF A 56 308 ALONG WITH THE LIFTERS

GrimGreaser

Right, just trying to figure out what was in my '56 308.

ski4life65

So, am I to understand that Hudson re-ground the 309742 cams but didn't mark them in any way to identify the difference? LOL That's good stuff. Sorry Erik I have one at my house if you want another one to compare, and confuse the situation even more.

GrimGreaser

So, some info I picked up while researching cam profiles. The major difference between solid and hydraulic being the open/close ramp profiles. Solids requiring a gentle start, to slowly take up the lash. Hydraulics having no lash can have a more aggressive open. But in all the threads on these cams its never been discussed the actual difference between the solid and hydraulic profiles of these cams. YMMV

[Deleted User]

ERIK, I FORGOT TO TELL YOU MY 52 HORNET HAS A LATER 53 308 WITH A 309742 FLAT TOP CAM WITH HYDRALIC LIFTERS.

[Deleted User]

Hudson put hydraulic lifters in because you could not adjust the valves in the Nash body. It was a bad mistake, because if you drove it on a long trip, oil got hot and lifters started to make noise. Try driving a hydraulic lifter engine on a hot day for about 100 miles, stop for a red light and listen. Give me solids and set at .014 and .017 and drive all day. Walt.

ivanz62

Attached tells how to ID a 309742 cam as hydraulic or mechanical. I have personally seen cams with this number and no other ID markings that were the 7X chain stretcher flat top, the 56 hydraulic, and exactly the same as 306344.

GrimGreaser

Thanks Ivan, that's just the kind of information I am looking for and confirms my understanding of the difference between the two grinds.