Hot Rods Spalding Bros Repro, for "Too Tall" Ganahl.

That's good because you're damn good at it! It was a pleasure to meet you last week and see this project in person. Pictures really don't do it justice! Thanks again for your help - I haven't got it finished yet, but what you bent up for me will work out great!

 

Tim, Nice meeting you as well, and thanks for the kind comments. I had a couple of other HAMB members drop by last night, Rob (Rotten Leonard) and his Dad Steve, along with Walt (Casual 6). I showed them the same junk, and fed them my familiar line of bull, and we went to my favorite Chinese Restaurant down the road ! Thanks to all of you for dropping by, it's great to talk projects, shop equipment, and racing. The best part of this hobby is the people !

 

Thanks again, we had a blast hanging out with you and Walt, really the highlight of the trip. Dad has a all sorts of plans for a board track style motorized bicycle now.

 

It's been a while since you've had a report on the roadster, so here's just a quick teaser update. I went down to Bob McKray's in Mission Viejo yesterday in my Old Reliable parts-chaser/pushtruck to pick up the finally assembled, balanced, and blueprinted 248-inch '48 Wayne 12-Port Chevy long block. It doesn't look like much on the stand in my garage, but what you can't see are the new Ross forged pistons, custom-made with a dome to match the cast JE pistons that came with it. I think I already showed you the cam Isky ground for me, after finding a very old forged-steel blank that he "Thought he had somewhere" in his shop--and did. I had previously found a set of n.o.s. chilled iron lifters. I also had about 20 Wayne pushrods, but the final glitch was that McKray found that only 6 were the right length. So I called Smith Bros. today and ordered a new set of tubular pushrods, plus new adjusters with 3/8" balls to fit the Buick rockerarms. Next I've got to make the oil system, and then attach the now polished/plated Wayne parts. I also got a new radiator made to match the original (turns out to be a '40 Chevy with a shorter core).

This is just a quickie update. More news when there's more to see.
Pat Ganahl

 

Well, It looks like I had better get in gear ! Great news.

 

@pgan - do you still have the old push-rods to use as pattern?

I know of 2 12 port engines that are slowly going together, and need these dimensions.

I love the way this car is going together

 

Stovebolt,
The pushrods that were the "correct" length for my engine are approximately 10-1/8" long (10.125). BUT, the first problem I noticed is that the Buick 8 rockerarm adjuster balls were almost 1/2" in diameter, and didn't appear to be seating down fully into the top cup of the Wayne pushrods. I have several sets of tubular pushrods (Isky, McGurk), for GM 6s and they are various lengths and have differing top cup sizes. So when I called Smith Bros. I got a very helpful/knowledgeable sales person who told me they could supply adjusters to fit the Buick rockers (diff. diam, and length than Chev/GMC) with a 3/8" ball. Then they will make new pushrods (5/16" tube) with a 3/8" cup on top, so that the whole combination will match the effective length of the one Wayne pushrod and Buick adjuster I sent them.

However, pushrod length in any engine--but especially early GM sixes--depend on several variables. First is lifter type and length. The solid chilled iron lifters are taller than later soilids or hydraulics. And did you know that pre-'54 Chev 6 cams have a smaller bearing base circle than later ones? This effects pushrod length. So does the amount the block or head has been surfaced or milled, and even the thickness of the head gasket. Same goes for the rocker shaft stands (mine are Wayne billet aluminum, not stock Chev or Buick). And so does the actual valve stem length in your assembled engine.

So the only way to determine correct pushrod length in any engine is to assemble the head and long block as they are to be run, install the cam and lifter(s), then adjust your rocker arm or rocker shaft height to get proper rocker-tip to valvestem geometry. THEN, measure the actual distance between the lifter cup and the rocker arm ball to determine correct pushrod length.

OK, class over. This is just one small step in engine blueprinting--something I prefer to leave to a builder like Bob McKray or Gene Adams.

Pat Ganahl

 

Pat, I'm curious as to why you chose a 5/16" diameter pushrod? To be historically accurate or clearance issues? Or are they 5/16" solid? I ask because 5/16" pushrods have been somewhat problematic in my O/T inline and 3/8" preform better when the engine gets stressed - RPM wise.

 

Thanks for the description of the pushrods you provided in your reply to my request @pgan. You have provided me with all the information required.

I agree, any major milling of the head will also contribute to the length of the pushrod. Some of the early 12 ports that have been sold over the last few years have been milled so much that they are incompatible with todays pump gas, and not usable on the street, except by adding fuel additives to raise the octane level

I believe McGurk or another early manufacturer of speed parts for sixes made roller lifters - I was offered a roller cam setup some years ago, but I managed my usual reply in being a day late and a dollar short. This setup would have required special order pushrods too.

These little differences that Chevrolet made as they produced different cssting of the 235's made life "intetesting". Who can't forget the rear main seal issues?

I might as well ask - anyone got a spare early 235 to suit a 15 bolt head?

 

To Frenchtown: Yes, Bob McKray was not happy to have to pull the head off an umteenth time after he installed a couple of the original 5/16" tube Wayne pushrods (with the Buick 8 rockers), and found he had to grind reliefs at least 1/8" deep and maybe 1-1/2" long in the top of the block to clear the pushrods. Remember, the guys running this engine in the '48-'50 era had broken a rod, and had acquired a fresh '48 Hi-Torque block, a prepped and fully drilled crank, and a full set of new JE pistons and GMC rods. But it was a bare, unprepped block on a stand when I found it, and the head was bare with no springs or valves. Most of the rest of the parts were in boxes (luckily including the rockers and Wayne stands). But since nothing was assembled, we're figuring some of that out as we go.
All the tubular pushrods I've gotten over the years from Isky and McGurk for Chev 6s have been 5/16" and I've never bent one. Even the 2" longer pushrods I got from Smith Bros. for the Iacono GMC are 5/16". Any larger would require similar block clearancing. But remember these are both 4-main engines that don't like crazy rpms. Six, maybe 7 grand max. So far, so good.
To Stovebolt: Chet Herbert not only pioneered roller cams, but ran a GMC in his '32 sedan. He supplied Ike Iacono. But when I was building the new engine for the Iacono car, Chet had no rollers and no suggestions. They're larger in diameter than most. Isky acquired McGurk in the '60s, and had a few sets of rollers, but they got snapped up by "parts hoarders" who won't sell. Very fortunately the late (and great) Joe Umphenour, who generously sold me the original Iacono Wayne head and Hilborn injector, later (and again generously) sold me a complete "spare" McGurk roller cam and kit identical to the one he set the NHRA D/Dragster record with. I've seen no other rollers available since.
As a side note, you mentioned wanting to duplicate the Safford-Shores Chevy 12-port Model A roadster. I knew my friend "Model A" Brian Bauer had the roadster, now painted orange and running a Chevy 4 with a '39 trans and the narrowed Halibrand QC as a street rod.. And I knew that longtime 6 wizard Keith Young was building a similar '29 Model A street rod with one of his Chevy Wayne 12-ports. But I just found out yesterday that it's Safford's engine he's got, denoted by 11 rocker shaft stands. It's a long story, but I can't wait to see this car.

All fun! Pat Ganahl

 

Happy Easter Pat ! I built the foot rests we have been talking about. In my stash, I had some genuine Dzus plates and oval head buttons. With the added heel loop, it was a natural to punch some louvers "down". I also straddled the floor support tube with a few more, of what Pat referred to as "dirt dispensers". Notice the new "bulls eye" pedal pads in place.....

 

I've seen it suggested a few times to ream the lifter bores out to take Chrysler Hemi lifters, 1.000" I think. I haven't come across anyone who has actually done it to know if it is worth the effort and expense, or if it works.

 

Good luck with the "dirt dispensing" Pat. I had 5 full rows of louvers in the belly pan on my Kurtis midget. The pan was still full of clay after some hot laps at Santa Maria, Tulare, or Ascot.

 

Well, at least the louvers will look cool down there!

Steve

 

Marty, any idea on how to ID torsion bar specs? I have a few that came with the rad I mentioned and have no idea what they are, spring rate, etc.

Thanks,
Steve

 

Steve, I don't know much about torsion bars, Gary Schroeder sized these, after I gave him corner weights. There has to be a chart with with a graph pertaining to diameter and length, solid and hollow. I bet the guys on the Vintage Sprint and Midget threads would know where to find out .

 

I would like to think you could use the Hemi roller lifters in order to grind a more aggressive camshaft. Coming up with a blank that is suitable may be an issue, as could justifying the price vs output differential of using roller lifters. The spacings of the lifters in the Hemi would mean that you would need custom made Heat treated stainless steel cross bars, in order to run them in a Stovebolt or jimmy six.

 

Good idea - I'll check that out.

Thanks,
Steve

 

I was lucky enough to see the engine come together at Bob's.......it's a thing of beauty.

 

A had a quick look in my parts pile and the lifter bore spacing for a late 235 looks very close to 2.00" (GMC about 2.250"). I see Crane makes 1.000" diameter roller lifters at a 2.000" spacing. I could confirm the lifter spacing when I can move some junk to get to my spare blocks. You're only looking at increasing the lifter bores by 0.010" so it might not be that big of a deal. For a Chevy anyway.
https://www.summitracing.com/int/parts/crn-66547-16/overview/

 

I just measured my 261 block, lifter bore spacing is 1.885" (measured with worn out, non dial/non digital verniers and bad eyes). So you might just squeak in with the 1.900" spaced lifters. Depth of lifter bore is 1.500". I hope someone gives this a go and posts the results.

From: http://www.cranecams.com/pdf-tech-tips/chrysler-big-block168-169.pdf

"The aftermarket blocks may also have relocated lifter bore spacing. While the standard lifter centerline spacing is 1.812”, there are also popular “Spread .100” (1.900”) and “Spread .200” (2.000”) configurations. Be sure of your spacing when ordering roller lifters so that you don’t exceed the travel capabilities of the guidebar."

 

I apologize for taking this post off track to address Steve's question.

Steve, Short of making a fixture to set inside a hydraulic press with a weight scale to measure it I would consider a little different tack.

When I built a roadster pickup I only could get a transverse, center-anchored torsion bar in one size - generally made for vintage funny cars and altereds. Too stiff. The car I was planning used an inline six and I knew it was going to give me a spring rate that was too high. So I ordered two sets of splined P&S torsion bar ends, cut them apart and welded up a set that was about 1 1/2 times as long as an original set. This effectively cut my spring rate by about a third, and sure enough, it handled and rode much more to my liking - softer with more rise on launch. Hope this helps.

 

Thanks FF, I'm actually wanting to sell them so was hoping to be able to get some specs but I appreciate the tip.

Steve

 

Does this help?
http://schroedersteering.com/torsion-bar-spring-rate-charts/

 

Well, it was time to tear down and remove the front suspension for final welding of all parts, on and off the frame. I also swapped the front spindles, for the 37-41's, versus the square ones that were on the car. I reamed out the spindles to accept the 3/4" shank, truck tie rod ends. It was also time to machine the proper drag link and tie rod. I intentionally left them long, thinking I can slot them for clamps instead of lock nuts. Assembled pics are next.

 

Look Ma, no jack stands ! What a relief it is to get it sitting on it's own front suspension. With the frame rails capped, and everything finish welded, it's fun to make adjustments to the ride height. By removing and changing the clocking of the anchors at the back of the bars, then make fine adjustments on the "jack screws". Now to hook up the front shock links.

 

Patrick and I had a long talk a few days ago concerning a few parts he is missing. If I had them I would have gladly made him an offer he couldn't refuse, but alas I didn't have what he needed. In all my GMC's I've never used over a 5/16" push rod and I made the ones I have now using Smith ends and tubing I bought from Aircraft Spruce. We also discussed roller lifters and he is correct. After 25 yrs I finally was able to get one of the new sets from Crower when he ran off a few. I have one GMC cam blank but there was no sense grinding anything without the lifters and Patrick agreed.
I admire the work that has been done to make this old/new track roadster come to life. I only hope Patrick can find those few rare pieces to bring it back how it was. They are out there and probably be junked when the people having them die. To bad.
I like this thread and look forward to the updates like every Stovebolt/GMC nut....thanks

 

nice!

 

Looking great, as ususal. Marty. Just wondering... based on your previous builds what do you think this ride will tip the scales at? Gary

 

Gary, I'm thinking it will be in the range of 1500-1650. Just a guess though.