Cam Tech

[Ol' Ron]

I built something lik that 25 years ago, and I still have it.. Gota get an grand kid over here so I can post somepics.
Gramps
PS this one is much nicer tho.
G

[Flathead]

Are the port flows mentioned here done with or without a head in place?

[Elmo Rodge]

I think I attached a photo of my injectors.
Wayno

[Elmo Rodge]

This plays to the tunnel ram idea. This is Flat32s design and I went 189 m/ph at Bonneville on gasoline 2 months ago.
Wayno

[Ol' Ron]

Atta boy Wayno. Sure miss those Bville days. Stay safe
Gramps

[Bored&Stroked]

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Originally Posted by Elmo Rodge

This plays to the tunnel ram idea. This is Flat32s design and I went 189 m/ph at Bonneville on gasoline 2 months ago.
Wayno

I think you need to add dual plenums on top (one for each side) and a pair of appropriately sized turbos . . . throw the boost too it Wayno!

Hope all is well with you - looking forward to seeing you at BVille once again. I'm just now going through the FlatCad engine to determine our next plans for an upcoming BVille build. We have lots to do, hopefully we can get er' done! Have a great Holiday Season.

[frnkeore]

Originally Posted by Flathead

Are the port flows mentioned here done with or without a head in place?

It says in the one I posted, that it has very thing but the piston.

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First, before I forget it. It looks like the cam blanks that Comp Cam uses, are on 107 LSA, for those looking for tighter than 111/110 lobe centers to start their grinding on.

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So, how do we make a adjustable timing gear.........

I'm posting a picture of the front of the cam and a aluminum timing gear so, you can see what we are dealing with, also a set of 1/2" bushings I made years ago, for a different application.

First, you will need a lathe and milling machine to do this accurately. Your going to be moving the cam by degrees. The radius of the bolt circle, is 1.06 so, each degree will be .0185 and the max you will be able to move it, will be +/- 5°.

I would suggest making the bushings first, using 1/2" round stock. I would use steel but, I think aluminum would work, too.

Part it off at .180 +/- .005. Then holding them in a collect or boring soft jaws in a vise, Drill and ream .310 (to be a close fit on a 5/16 bolt), first one on center, then as many as you want/need, off center, for your application, in multiples or fractions of that number (.0185). 5° is .0925 and the max, before breaking threw the edge of the bushing.


Using a good drill press or mill (square to the table), drill the offset hole (circled in the picture) to 15/32 and then ream it with a 1/2" reamer. You need a rotary table or CNC machine next.

Set up a 2.623/2.6245 spud in the center of the rotary table, D&T a 3/8 or 1/2 hole, in the center, for a hold down washer no larger than 1 3/4 dia. Then, D&T a 5/16 hole at "0" 1.06 off center, on the rotary tables scale. Bolt the timing gear down, with that bolt, install your center hold down and take the bolt out. Then machine +/- 5.5° (for a little clearance), both sides 0, then both sides of 90° on either side of that. The slots should be at least .330 wide. Finally you will need to make a washer that spans the 1/2" reamed hole, for even pressure in the 4 locations.

From there, degree your cam in with the 0 bushing, then install the off set bushing that best matches where you want the ICL to be.

I have NOT done this, myself. For those that want to do this, please give us some feed back as to anything I may have over looked. This is all done based on my timing gear and the Ford cam drawing.

[Tim Ayers]

Epic thread...

[Pete]

The offset bushing method that Frank describes is a very good way to adjust the cam and I have used it many times on OHV engines.
However, on flatheads as long as there are early press-on gear cores available, they are much easier and CHEAPER to use. You just press the gear off, move it and press it back on. If you do the adjusting with only one cylinder mocked up, the process goes quickly.
The straight cut performance gears are available in press-on also.

[Elmo Rodge]

This is the completed plenum.

[frnkeore]

Here are some more. The 21 stud cam timing and the pre '49. Again all the specs are the same for all the engines and 8.70 C/R.

Note that the early 21 stud, has the same lift (.292) but, a lot more duration. Has any one tried it as a replacement for the later cam? If so, how was it?

I'm also including specs for what Comp Cam sells. I did the smallest "Thumper" on one of the other charts. No one ever talks about these. They would be pretty good if you took about 20° out of the exhaust advertised duration and 6° out of the .050.

[Ol' Ron]

During my stock car days, we just slotted the bolt holes, moved the cam where we wanted it. Placed star washers under the bolts and went racing. Never had a problem. However, after a few years, I discovered that the air pressure in the right front was more important than the cam timing.
Gramps

[outlaw]

Frank, this last chart set came out larger & prints out good on my copier. Thank you.

[tubman]

Originally Posted by Ol' Ron

During my stock car days, we just slotted the bolt holes, moved the cam where we wanted it. Placed star washers under the bolts and went racing. Never had a problem. However, after a few years, I discovered that the air pressure in the right front was more important than the cam timing.
Gramps

Yep! When I was racing, the most important item was the logbook that had the initial gears, stagger, and tire pressures to use when running on the many different tracks we encountered.

[Ol' Ron]

I would expect that Bonneville engines have to be perfect to atain the record breaking speeds. Circle track has too many variables. However, I'm sure the timing is one of them!!

[frnkeore]

Originally Posted by outlaw

Frank, this last chart set came out larger & prints out good on my copier. Thank you.

I don't know why but, even though I do everything in the same format to post, the more charts I post, the smaller they get on the forum?

I would still like to get the Advertised or Seat to Seat timing for the L100 cam, if anyone here has that info, it would be appreciated.

[Zeke3]

Frnkeore, thanks for starting this thread, it is very interesting. What calculator are you using, is it one you created?

[frnkeore]

Originally Posted by Zeke3

Frnkeore, thanks for starting this thread, it is very interesting. What calculator are you using, is it one you created?

It is a Pat Kelly program. Search his name with dynamic calculator and it should bring it up.

As promised, I did charts on the L100 and the H-V 12. The info I have on the H-V 12, is that it is a '36-'37 cam and no lift info. I'd say that it would be under .330 lift, from that time period.

Well, Ronnie was gracious enough to give me the seat to seat timing of the L100 off one of his cam cards. Thank you Ronnie!

I like the 108 LSA and the ICL of 104. I had wondered if that combination would work on the V8. It is what has been used on higher rpm, OHV engines for a long time and I like a narrower LSA.

The info that I had gleaned, off this forum, regarding the L100, is a bit different. They only had the .050 timing and .375 lift but, there sims to be several LSA's. There seems to be 4 (5 including Ronnie's) variations I found. 112 LSA adv 4, 114 LSA adv 2, one that only says 111 LSA and 113.5 LSA adv 3 (called a blower cam). I didn't chart the blower cam or a straight up 111 LSA versions.

Note that Ronnie's cam card version, has the highest DCR of all the others.

Maybe KiWInUS could help us, in what versions he grinds.

[Bored&Stroked]

I've done quite a bit of CAM profiling - starting with graph paper, a degree wheel and a dial indicator when I was about 16 years old (long time ago). I was very interested in comparing Harley KR roller cams with flathead cams - and used my initial research to get Ed Isky to grind a couple flathead rollers for me (I made the billets out of 8620 AQBQ steel).

I graduated to better methods over the years and have owned the CAM Analyzer program for many years. Attached is a document I put together 6 years ago on some summary information on some of the cams I was looking at (that I own).

I'll also include a few graphs of a custom roller cam that I was using for one of my engines . . as compared to the Isky 404-A radius lifter cam. You'll see that while the 404-A has a faster initial ramp than the roller, ,then the roller "catches up" after about .100 lift. As Pete has said numerous times, what really makes the 404-A run are the fast opening ramps on it. Anyway, enjoy the material . . .

I'll have to see if I have a copy of the Isky 505-A profile information with me (am out of town), if I find it, will post it.

FlatheadCamshaftSummaryData.pdf

IskyRR630RollerVsIsky404ARadius2DegreesAdvanced.jpg

[Bored&Stroked]

It is important to note, that just knowing the lift, duration at .050, LSA, intake centerline and timing events are important, but there is a lot more going on in any particular design/profile to understand how one cam compares to another.

Unless you have a full graph of the profile(s), and understand a lot of the details it is difficult to compare them (other than at a really high level). Two cams with the same basic "numbers" can perform very differently . . . based on their profiles, ramps, lifter designs, jerk, etc..

Here is a little PDF from Dema that may help folks get into the details just a bit more . . .

http://www.engineprofessional.com/ar...Q215_62-66.pdf

Enjoy!