Projects DRAG SNAKE "Vintage Terror!"

The driver of above was Kirkpatrick and was renting the house next door In 66-67. He worked
for Shelby in this era but left and did work out his garage for a period. I lost contact and hadn't seen
his name for eons.

 

So for quite a while now I have been trying to piece together a Dragon Snake Library. At some point here pretty quick, since as you know from the first page of this thread I own DragSnake.com, I want to build a web page. My hope on that page is to be come the preeminent go to source on this handful of cars. I have been collecting photos and piecing together their histories for a while now. During this research I have run across the name of Colin Comer several times attached to photos and an occasional article. It came up again last night and so I simply searched his name and holy cow I think I found the Holy Grail (of Cobra info anyway)!


I had no idea this book existed. I went to order it last night and first place Google took me they wanted $350 for the book! Holy Grail or not at that price it better be made of gold (LOL). I shopped around for a bit and found a much better buy (saved $310 on a used one from ebay). But none-the-less I am excited to get my hands on it.

 

Your book purchase further supports one of my favorite things about this build, and I suppose you and your Pops. That Southwest Missouri thriftiness (that is so ingrained in our culture here) winds through the build.

I mean, you're building a Cobra, so common perception would be dropping cash left and right would not be flinch-worthy, and you have spent some, but you don't if you don't have to. You put the money where it matters, and don't mess around on the rest. You also fess up when you screw the pooch and have to constructively spend your way out. It makes the whole journey more interesting... Or at least, more familiar.

 

I also had to do some back tracking on both parts and budget yesterday. As you know the corrected valve springs made it in this week and are being installed as I type. However that is not the end of the story as far as additional parts. Of course we have to get new head gaskets. I mentioned earlier about going to Cometics on this build because I really didn't know much about the set that came from Ford. After talking with them yesterday I found out what we had on there is about the best we can buy. I mentioned Cometic when I was talking to them and their race tech guy said that was an option but if he had the choice he would stay with what we had as they are awesome. So I guess I will take his advice.
These are Ford Racing M-6051-R351.


And while we are at it since we know there are no clearance issues with the Jesel shaft rocker system I upgraded us to head studs. I wanted to do that in the first place and planned to do it after we found we had the wrong studs (if you remember we needed the 351 set). When I ordered them from Jegs I accidentally snagged the bolts again and didn't realize it until they arrived. At that point I said screw it we will just use them. But now since we have the chance (unfortunate as it may be) I upgraded us to the 12 point stud kit.

 

I am pretty excited today. Here in just a bit I "may" have the final answer to what color the hardtop on the Cobra will be. It has come up a few times earlier in the thread with folk suggesting something other than the same color as the car. I sort of agree (as did Dad...you remember his "gel-coat" black attempt to offset the epoxy primer etc...LOL). For a while I have been considering a black vinyl top on the roof (I even have a Dragon Snake Photo which is currently MIA of the light blue one wearing a vinyl hardtop).

A while back, I actually went to a very good upholstery shop here in town that sort of specializes in vinyl tops. I showed them the photo and I will not tell you what the quote was for this tiny little hard top. Suffice to say it was the kind of price that makes think I could probably just do it myself. You know I pretty much live my life by this saying: "It can't be that hard to do, I have seen the people that do it!" LMAO!

Anyway the top is down the road a bit so has not been on my radar for a while. Then Monday a vinyl salesman dropped in for a cold call (of course you all know that is what I do for a living, vehicle wraps and vinyl graphics etc.) He is not my normal supplier but it is always good to see what is new on the market etc. It was a very standard cold call for about 10 minutes but then he says he has something new to show me.


It comes in several leather colors this is the black. It is a tactile vinyl that is soft to the touch (meaning it feels like real leather)....looks like as well. It has the same style air release adhesive as standard vinyl etc. I am pretty excited about this because it looks amazing and it is as removable as any other vinyl graphic. This means we can wrap the roof and see what we think. If we do not like it at some point, we can simply remove it. I got enough to do the top and the dash and believe it or not I didn't even spend $100.

 

I've wondered about wrap for vinyl tops. That really looks good, I'm anxious to see how it turns out!

 

Kewl. And in your wheelhouse too!

 

I can see all kinds of early Fords with filled roofs getting a bit of this for their "restoration".

 

Picked up my heads yesterday so we should be on the right track. They only needed .015 shim to hit our 2" height so we have plenty of room now and 250 lbs of seat pressure plus what ever .015 up adds to the equation...LOL.

 

Well it has been a very long weekend in the shop. First we had some head stud issues but nothing that little HAMBer chat couldn't fix (thanks Jackson and James). With that little hurdle cleared we installed the heads for real (AGAIN)!


A bit later we are rolling the engine around and installing the rocker arms. Obviously things look much better in the spring department with no coil bind what so ever. Now again, the only reason we are doing this right now is to double check rocker clearance on the valve cover extension and try out my Cam Correct lash tool (which is what started this whole mess in the first place. LOL.

So we get all the rockers on and one at a time we put them on the base circle and zero out the lash. What I notice immediately is we have to spin the lash adjuster almost another full turn to get any lash at all. It only takes a couple of cylinders to see the trend here but in the end it is obvious we have an issue. With all the lash adjusters turned all the way out and on their outer stop position I measured the lash to see what we have. I know we can not run them here but I just want to see what we had. They are all over the place (but all within .050).

My cam card says .025 lash and I could actually get to that on about 75% of them, the rest were already below that mark. Not that we would ever even attempt to run it that far out of the sweet spot but I thought maybe (being shaft rockers I could use those numbers to re-measure for the correct push rod. I mean I did a lot of math. I know the length of the current push rods (6.800) and I know how that number effected each valve. I also know how much movement the adjuster makes (.120) from lock to lock and I know I want to be as close to the middle of that (one full turn) which is .060 (which makes one half turn of the adjuster .030.

So my thought is pick a new push rod length that puts them all as close to the sweet spot as possible. So I took .060 off of 6.80 which would put my rocker back in the sweet spot and played with that number either direction to find a number that kept all 12 valves as close to (or at least equally aft or forward of dead center). Then I had a thought, how does the rocker ratio effect this equation or does it? I started to think it is not as simple as say you need .035 more lash so just take .035 off the push rod?

My brain was already hurting so I just stopped. I know I have seen tech articles where engineers use a formula to decide rod length but I have no idea where it was. I tore up the internet yesterday trying to find a formula or similar information but I couldn't find it. Maybe I am using the wrong search terms or maybe that article was in a dream or something, I don't know! All I know is MY head hurts and MY heads are already torqued down for the second damn time and I am thinking we are going to have to simply go back and some how put the test springs back on and start the process again. Unless someone has a better idea or knows my missing math....LOL

 

Get or make an adjustable pushrod, make everything happy and measure. Order new pushrods and no math required!


Sent from my iPhone using H.A.M.B.

 

Give me a call if you like, I don't have any math for you but, I can tell you how to check for correct push rod length.

 

Dam, that is discouraging

 

It is sort of a pain in the back side but this is one of the most important steps to making sure we make good horsepower while at the same time taking care of our parts. So we have to get this correct no matter what it takes!

 

"to find a number that kept all 12 valves as close"
Yep, bad math.

 

So after a fairly somber day of contemplation at work yesterday as I thought about heading back to shop ready to do what ever it took to get it right. Oh by the way, I did have one bright spot yesterday as I received a visit from fellow HAMBer @Peanut 1959. Thanks for dropping by and hanging a bit it is always great to put a face with an avatar!

Anyway, after dinner Dad and I headed out figuring we had about an hour or so before Street Outlaws No Prep Series came on. LOL. We hit the shop and completely disassembled the Jesel hardware.


Then I dug out the old compression checking hose and pumped up cylinder one to hold the valves in place. We removed the Pac springs and installed our lightweight test springs once again.


We re-installed the rockers with the same adjustable pushrod as before. I checked it the same way. We rolled the engine over until the exhaust valve just started to lift. At that point, on the intake side, we put one full turn back in the adjuster that we are looking for, stuck a .025 feeler gauge in it and spun the nut on the adjustable push rod. When we were happy that it was tight with out starting to compress the light weight springs etc., I carefully removed and measured the pushrod...Any Guesses?!!!

Well if you had guessed 6.800 on the freaking dot you would be correct. Now that is fairly disconcerting as that is the measurement we got the first time several months ago (well actually 6.798) which prompted me to order the 6.800 units! So we sat with that for a while scratching our heads (and no I didn't throw anything) LOL!

Then I happened to look at the valve tip that we had marked but in the rush to measure the test push rod really didn't check. I was not happy with what I saw there. It was a bit outboard of center and extremely wide! Now don't forget these are shaft rockers so dealing with the geometry is a bit different. The length of the push rod does not effect this patch, it is the solid shaft that sets and adjusts it. If you want to make a change there you have to shim the pedestal. So we started to experiment.


Above left is the wear pattern I saw when the Jesel pedestal was just bolted right to the head. As you can see as we add shims the pattern got better. The first shot was .015 and as you can see it cleaned up and narrowed the patch quite a bit. We decided to keep going. I only had .015 shims in the tool box so we doubled them up and at .030 I really liked what I saw. It is still just a shade outboard but much more defined and narrower. Finally we stuck another shim in but as you can see at .045 it was headed in the wrong direction as the line got a bit fatter but more importantly started to move more outboard etc.

So we put .030 worth of shims in it and installed the rail again. We grabbed the adjustable push rod and repeated the standard steps and take a look at what we got.


So that would seem fairly predictable right. We added .030 of height to the rockers so the pushrod should follow suit as well (and it did). But as I told Dad we are in the exact same boat. The 6.800 that we measured and ordered didn't work so what chance does raising the arms .030 and getting a 6.830 rod do us. In my humble opinion we are right back in the very same boat. We have better geometry but we are right back were we started on the length issue. Correct?


So we sat with that a bit. Now when I was sitting there Sunday night playing with all the figures and where the sweet spot might be I had written down getting a .035 shorter push rod but then talked by self out of it thinking maybe the ratio played into that math etc. But now here I am with 6.800 original push rod and with the shims under the rocker pedestal needing a push rod that is .032 (according to the calipers) longer. So for grins I snagged a couple of the original 6.800 rods and dropped them the holes and installed the rocker arms on them.

With them in place now I could turn the adjuster back down one full turn before setting the .025 lash. As you can see above I installed the other three cylinders aft of the texs springs with the real deal and all of them hit the sweet spot with the original push rods and the .030 shims under pedestals! SO...... Believe it or not, I have exactly what I need now with out ordering new push rods etc. We are going to wrap the heads up tonight and get this crazy outfit back together....


....AND...just for good measure...there is your 90 degree angle at half lift James! I have said it before and I will say it again. I would rather be lucky than good any day! LOL!

 

So you were listening, you just took the long way there.

 

You do need to just lay that straight edge across the shaft mount center line to the roller tip center line to the valve center line.

 

Hey, Randy, it was great getting to visit with you yesterday. Thanks for making time in your day for me.

As I said, I really enjoy reading about your trials and tribulations! And I really want to see the Cobra run at MoKan this spring. It'll be only my second time at a dragstrip!

 

If you are in Jeff City, you are about 10 miles south of me.

 

No way! Yep, I was born and raised in the capital city and I'm still here. The car in my avatar pic is mine, though it's been off the road for 20 years, now. My family has always had Studebakers.

 

Not much to report from the weekend as far as progress. We helped my Aunt move on Saturday and to be honest when I woke up Sunday morning I could barely move! LMAO. So I pretty much lounged the rest of the weekend away. I did find something interesting though.

This is a page of original Cobra fodder from way back in the thread. I guess I missed this little tidbit on the Hardtop! I have been thinking all along that when the first "DragonSnake" rolled into the track and found they had to have a roof, that they simply fitted one from an MGA. But according to this little article AC built the hardtops and probably already had them in stock.

 

Playing around with some trailer graphics...LMAO!

 

Cobra racing. Americas most dangerous sport. Maybe a picture of two snakes lined up at the tree. lol

 

You keeping that trailer under 24 hour surveillance?

 

He doesn't have to worry bout the trailer hell james they left the last one and just took the car lol. Besides it's a ford they won't be interested anyway probly be afraid it would be broken lmao. Randall you got this thing running yet time is running out my friend

 

We are close. Missing shims arrived today so ready to finally assemble the engine for good...should be installing it this weekend!

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I thought The D.M.V. required that every Ford came with a trailer, My guess is if you build it ya got to go out and buy one before registration

 

Correct Norb....here is the Missouri Form:

 

Love it , gotta get a copy for the Ford guys at the restaurant. lol
Going to have some fun, tell them our new Governor is considering this.
Randall am sending a P.M. with my e-mail address for a copy.