Projects Austin Somerset Gasser Build (DragNasty)

Junior Thompson built some of the nastiest best sounding early blown hemi engines. He ran a certain no longer obtainable non- roller timing chain. He even ran these in his funny car engines. He would take one of his timing chains and try to get the links on one side of the chain to touch the links on the the other side with no gears. They would not touch. Now if you're building blown early hemi engines that run better than Junior's did... you're pretty bad ass.

 

yes he did great with what was available at that time. in his day .500 lift was as big as it got on a hemi. they didn't have the cam grinds they do today. they also didn't run .100 long valves. nor did they have rocker gear to handle todays lift. todays engines with their long valves and improved valve trains can handle some serious spring pressure due to more room under the retainer. with todays improvements there are many capable engine builders out there that can make more power than the masters back in the day. todays dragsters are going 330mph. front engine dragsters are going 260 plus. nostalgia gassers have a 7.0 class. it would be interesting to see what junior Thompson could do today.

 

Well Jesel pretty much shot my engine rebuilding weekend plans down this morning. When I called them about a set of rocker arms I was inquiring about the Sportsman Series. They didn't recommend them for a supercharged car. Their suggestion was to upgrade to the Pro Series with their solid rocker arm bodies. So I decided to pull the trigger. They arrived this morning but they are not the solid body style they are a lightened series.


I called them and they said I should have requested the solid. I said you guys recommended the solid. So long story short, round two of rockers on the way but certainly not by this afternoon!

 

Your going to love them. When we recieved our T&D's the guide plates were gone and with hard 1/2 mile dirt driving the valve lash never has changed.

 

Took a little break from the build this morning and joined "wrenchbender" and a bunch of this race car buddies at Bushmaster's Drag Racing Museum just East of Strafford, MO. Some killer old cars, several on lone from Big Daddy's Museum in Florida.










Tons of photos and drag race race memorabilia (honestly more than you can see in one stop)


This was my favorite table, what can I say, the man has great taste!

 

Then in the afternoon be we got back to work, without the correct Jesel stuff we can not finish the top side, but we can certainly button up the bottom end. So we started by removing the timing chain, putting the gear back on (with the cam button installed) and then installed our new two piece timing chain cover. After it was on we then spent a while trying to contort the dial indicator holding device in a fashion that would allow us to hit the hole in the cover.


After we finally got it in place we check the cam end play and it was .057! We are looking for something between .005 and .010. So we un packed the shims that came with the cover, Dad took his calipers and measured the entire pile of shims (5) that came in the kit. He said they were about .049. So we took it all apart and put the whole stack in behind the cam button. Then reinstalled the cover and checked it again.


I have to say looking for something between .005 and .010 ---- a touch over .007 is about perfect. So we greased the daylights out of the chain and gears, put them all back on including the shims, cam button and button hold down. Then we installed the front cover for good (I hope)...


We flipped it over and installed the oil pan. Which was not fun, are we sure this stupid thing came off this motor...LOL Ever have one of those days in the shop... But we finally got it back in place.


We were on a roll so grabbed the inner hub from the ATI Super Dampner and pressed it back on the crank.


Then we installed the rest of the dampner making sure to clock it for TDC (that will help later).


Then just to ease our mind, we bolted on the new electric water pump to make sure it cleared everything.


Like a glove a baby!

 

Firing order reminder installed on the firewall...

 

So after confirming there was no difference other than weight, between the lightened rockers I was sent accidentally and the correct solid rockers that Jesel is scrambling to get me, I decided in the mean time to move on. So we dropped the used cometic gaskets in place, installed the valves and test springs in the head and popped the head on the block. The goal was to double check piston clearance and measure for push rods.






We test fit the new Jesel rocker bases and carefully removed a couple of the shaft rocker arms from their plastic wrap. I was expecting to get the correct rockers later this week but just as I was temporarily installing these I got an email from UPS confirming an overnight delivery from Jesel for tomorrow. That is pretty impressive.

Anyway we dropped a bit of play doh on the top of the pistons, installed the heads and torqued them down with the ARP head bolts from the original build. I got the old adjustable pushrod out and checked the exhaust first, it was around 9.250 (Dad wrote it down). Then the intake, it was just a bit longer than 8.250 (of course at this point I am just laying the rod on a tape measure. Dad started to write down the intake number and then said, wait a minute, that a stock BBC push rod set. He was right, and unfortunately, our original comp cam push rods were shorter than stock, so looks like a new set of push rods in our future.

AND...by the way the Play Doh castings were perfect, plenty-o-clearance!

 

Man you going to have to grime that stuff up......

 

And then just thinking I would not want a gasket making a step in my combustion chamber....But maybe I don't know everything?

 

That is the original set of Cometics, the new set from them are supposedly specialized for the Brodix Race Rite Head, I have not opened yet but I know they are the same thickness etc. When we do it for real I will shoot another photo to show whether or not Cometic designed a step in them etc...

 

I'm looking forward to spending time on the coming cold Winter days, watching You Tube vids, of the new engine pushing Dragnasty down the strip, in your coming Summer.
Wear the Blue Max hat, so we know which one is you.

 

Man, I don't know what they sold you, but I really don't think those springs will be strong enough, especially under bOOst!!

 

TO BE HONEST... I had a hard time finding a set of lightweight springs. Dad said maybe we could just use the springs from the original build, he figured they would have about the same seat pressure as test springs!
NOT FUNNY!

 

Hi
just spent time reading all the posts with interest.
I to built a blown 454 chev and ran it in a RED. The heads had Manley valves. What happen was the tulup on one of the exhaust valves broke half off in #3 cyl. and stuck in the #6cyl piston.
I got hold of Manley as these were new valves. They asked me if I was running gas or alky,
I told them gas and he said I had the wrong valves and need to run valves for blown gas. You should check this out for yourself.
Regards
Dave
(titanium only on the exhaust)

 

Thanks for the input, I really appreciate it. As you have seen, the valve train was basically blue printed by my cam designer. After he sent me the quote for the list of parts he was going to order for me, I called all the vendors involved. When I spoke with Manley I told them exactly what I was building in great detail. They recommended their Severe Duty SS Valves exactly as my Cam Designer had chosen. Now the difference might be that I am running e-85.

 

So I ask you, where does it end? As you may have read, Saturday we measured for push rods. Of course it would be my luck, the custom Comp Cam Magnum Rods are too short and are essentially useless, toss them into a very expensive pile of slightly used parts from round one that for one reason or another did not make the cut.

It was obvious to me while measuring them, that the new Jesel rockers seem to require the ball style ends. I decided since I was on the hunt for new push rods anyway, I would just call them to see if they had any specifications or at least recommendations in that area of the valve train.

What I found out was at least a 3/8" if not 7/16" push rod (duh) however with a bit of a twist. They have to have 5/16" ball tips and the tip that encounters their rocker cup must be compatible with its H-13 Tool Steel composition. Not such an easy find, especially for the 7/16" rods (what I am basically saying is not an off the shelf item from JEGS).

I talked to quite a few suppliers of said custom rods including Smith Bothers and others but I think I am going to go with Manton. We are going to double check for clearance tomorrow but the goal would be 7/16" at least on the exhaust. Believe it or not, Brodix couldn't tell me if that was possible, said I would just have to try one and see.

 

But here is some good news. The corrected rocker arms (solid body) showed up today as promised.


While that certainly falls in the realm of good news it not exactly what I was driving at. Take a look at this!


I quickly popped them on my still bare test head and then for grins dropped my vintage M/T valve covers in place...


And bing...again "like a glove baby!" Plenty of clearance and no more spacers thanks to loosing that crazy stud girdle!
Very exciting!

 

You need a tapered push rod...being you are not running guide plates.

 

Yep...that is what Manton said too, at least at the lifter, the ones they are building for me are tapered with 5/16" ball ends. The Rocker end tip and rod body will be tool steel and the end for the lifter chrome moly. They are three piece units.

 

So since I measured the push rods to be stock length I decided to do snag a couple (all of $5 worth for one of each). We installed the finished head and double checked the fit and whether or not we can get away with 7/16" on the exhaust.





Unfortunately it doesn't look like the 7/16 will work. AND the stock exhaust push rod is just a bit too long. Basically a perfect fit but with no room at all for lash later on. So we will make that adjustment with Manton when we order them.

Sent from my SM-G930V using The H.A.M.B. mobile app

 

Just to double check on the 7/16" push rod possibilities, I came up with this. Honestly there are two questions here, one, are the holes in the head big enough to facilitate the larger push rod through the full cycle. And two, with this rocker configuration, would they clear the cylinder walls in the valley.


I took my stock 5/16 push rod (.3125) and added an 1/8" wall hose to it (.1250). The math says that equals 7/16" (.4375). But this little test is obviously skewed a bit as I have basically just added the entire 1/8" to one side of the rod. However I did that on purpose. There is only one side of the rod that is in any danger in any given hole. So if we put this rod in tonight (with the 1/8" towards the cylinder wall and it clears, I know I still have 1/16" in the bag. We shall see.

 

Well after moving that push rod around my desk several times Friday to insure I didn't do something stupid like walking out of the office with out it......... I walked out of the office with out it. So we headed back to Springfield this morning to have breakfast and pick it up. After getting it home and testing it on cylinder one, it the touched head. You could still turn it but you could feel the drag. So we had to get a bit more precise to know for sure.


So I took the rod and started wrapping it with strips of duct tape rolled longways on the rod. After several layers and checking with calipers, we ended up being .010 over the 7/16" goal. We installed it and if you look closely, you can see a tiny bit of daylight between the head the rod (plus my 0.10). We checked all the exhaust rods and now feel confident we can get away with larger rods.

With that being said, our test fitting and measuring is complete, time to go ahead and build this head for real!


So one at a time we dropped the locater rings in place, remember because of the larger springs (that basically took up the entire pocket) we had to go with this internal style locater instead of the cups.


We greased up the valve stems and slid them in place. Then we carefully worked the spring loaded teflon guide seals over the stem and then down in place on the guides. I used one of the titanium retainers to help install the seal both on the stem and then carefully down over the guide.


Then we dropped the spring with the retainers in place and grabbed the air powered spring compressor.


That's all she had, same as before (even with turning up the pressure on my compressor) that is all we got.


So same as before we installed the standard hand operated unit and finished the job. Actually I think this is about the perfect way to do it. The air unit has the spring, it is not going to go anywhere (kind of like an insurance policy). Then the hand held unit makes quick work of the last 1/2" or so to safely install the keepers.


By the way anytime we have touched the springs or really any part of the valve train, it has been with the latex gloves on.

 

With the second head complete we are ready to install both of them for real. We flipped them over and made sure everything looked good and clean. Then we popped open the new Cometic head gaskets.


We oiled up the cylinders with a light coat of Marvelous Mystery oil, wiped the head surface clean and dry and then installed the Head gaskets.


We carefully sat the heads on place.


Then we made sure our washers were all on correct (Chamfered side up). Before installing them we put ARP Thread Sealer on them and then the ARP Ultra-Torgue Assembly Lube (the blue tube) on the washers and head bolt shoulders.


After hand tightening them we torqued them to 70ft.lbs. in three rounds of the general Chevrolet head torque pattern.


After we had them both complete we installed the Jesel Pro Series shaft rocker system.

 

After the heads were in place we did a quick test fit (double check) to make sure the supercharger intake fit properly. If you remember we had to do quite a bit of grinding on original 840 heads. But no issue at the all as the intake appears to fit like a glove. HOWEVER, you know Dad and I are like a couple of kids with model car, it is hard not to take sneak preview. In fact I don't think either of us said anything, we just started grabbing parts to set them in place. So here it is!








Very little was accomplished in the shop after this outside of photo taking, walking circles around it, and smiling our backsides off!

 

Looking Great and your careful assembly is just what it needs! Gary

 

NICE!!

 

Having learned the hard way on my 429 Ford with splayed valve arrangement, about pushrod flex, I'm just wondering if .010 clearance is really enough at high RPM's even with 7/16 push rods. Keep in mind that I don't know much and this is just a curiosity question.

 

No not just .010...the daylight you can see plus the .010 in the bag from my tape job being a bit larger than 7/16.

 

Got it. My mistake!