Pat, What kind of price are we talking about as "affordable"? I might be interested, just to sock them away for later. -Dave
No worries Bill! I know who has the pattern for the Valve cover I will ring him tomorrow and see if we can get a batch cast. I can't promise anything but I can at least try.
My pics from Pebble Beach SANY0416 by Jimmy Bs 1925 Chev, on Flickr SANY0412 by Jimmy Bs 1925 Chev, on Flickr SANY0413 by Jimmy Bs 1925 Chev, on Flickr SANY0410 by Jimmy Bs 1925 Chev, on Flickr SANY0411 by Jimmy Bs 1925 Chev, on Flickr DSCF0871 by Jimmy Bs 1925 Chev, on Flickr DSCF0867 by Jimmy Bs 1925 Chev, on Flickr DSCF0860 by Jimmy Bs 1925 Chev, on Flickr DSCF0859 by Jimmy Bs 1925 Chev, on Flickr DSCF0858 by Jimmy Bs 1925 Chev, on Flickr DSCF1094 by Jimmy Bs 1925 Chev, on Flickr
Wow!! I'm sure glad Stumbled on those old motors, the HAMB and this thread. I am having fun. Thanks for the photos Jimmy B.
I wouldn't worry too hard. The issue of Hop Up where the revealed the S/G roadster had been found also used the "Spurgeon" spelling, so you're in good company. We talked transmissions a bit earlier. Does anyone know how close a Ford Model A transmission comes to working on the Chevy passenger-car bellhousing? I have a Model A unit I'd like to use, as my Chevy didn't come with a trans. -Dave
On the rockers. The ratio of 1.72 to one. Is that the same as the Nash rockers? Is it the same as used in the original car?
We at the HAMB applaud you for preserving a piece of hot rod history. I had the pleasure of speaking to Mr Giovanine many years ago by phone. It was an experience I'll never forget. Bob told me the reason a '25 block was more desireable was the center web was solid and not weakend by the distributor drive. I asked him if he knew where I could find an Olds 3 Port head He said he had one I could have! He left it for me at Taylor engines in Whittier, CA. This head had HUGE intake ports, beautiful tulipped valves, and the infamous Nash rockers. ALL FOR FREE! What a great guy!
Bigcheese - I measured both. The ford trans input shaft is about 7 inches from the front of the case to the end of the splines. The Chev is 5-3/4 inches. The pilot brg. portion is about the same length on both, but the Ford is larger in diameter. The T.O.B. coller and bearing on the ford are LARGE compaired to the Chev. The flywheel will need to be machined or changed and another clutch used. Note: the T-5 shaft is roughly the same length as the Chev and might be an easier swap. - Norm
I guess I’m not surprised to hear that the Ford transmission is seemingly a heavier duty part. Reading up on the 4-cyl Chevrolets, the Ford T, and the Ford A, it seems that the Chevrolet design borrows heavily in design from the T, and that more parts (such as the aforementioned rear end gears) actually interchange between the T and the 4-cyl Chevies than between the T and the A (some crediting this to Henry's desire to distance himself from the GM product). Another reason I’d like to use the A trans (in addition to already having one, and trying to keep the parts pool 90%+ pre-‘32), is that I’d like to use a Model T Ruckstell 2-speed rear axle, and from a previous Banger Meet, I know how to mate the T torque tube to the A transmission. Maybe a similar process could be worked out with one of Crazydaddio’s T5-to-Model A-tube adaptors... Thanks much for the information! -Dave
There was a thread on mating a T5 to a early Chevrolet 6 about a year ago- it wouldn't be that difficult- just a spacer... if I were a rich man (all day long I'd biddy, biddy etc), I'd be telling you about the spacer that Stevie G and I already made... but I digress
Didn't Jimmy B already work up a trans adaptor of some sort? In any case, I'm not too awful worried about that end of the transmission, it's the rear. I could probably be talked into going 5-speed, if I knew I could still use a T rear axle. -Dave
I did an initial mock up to mate a Toyota Hilux 5 speed behind my '29 chev six. I didn't go any further as I bought the '25 and the '29 is basically all sold now. The gearbox ended up in my dads Hilux when his needed replacing. I think Herb adapted a later gearbox to his speedster.
Re the finned valve cover. Sorry there is no plan to cast anymore at this time. Looks like I will have to get back to working on the pattern I started.
I have never had a set of Nash rockers to actually measure them, but they have been identified as 1 1/2-1 many places in print. The original Olds rockers are 1-1, and puny, if that is what you are referring to as the original car. Herb Kephart
Herb- No, I was refering to the Rockers In the restoration engine of the Spurgeon/Glovanine engine. Were the rockers in the original car 1.72 to one. If not why were they made that way in the restoration. - Norm
I'd like to see/hear more about what specific 305 pistons and what rods were used in the restoration!
Jimmy B wrote- "I think Herb adapted a later gearbox to his speedster. " Correct Jimmy. I cut the rear tranny mount surface off the steel Chevy bell hsg., shortened the hsg. a bit, welded a new rear plate (1/4") on and bored and drilled that to fit a Volvo 4 speed. I like the Volvo M40 and up 4 speeds as they have a good ratio spread, and are near bullet proof with the amount of torque that we develop. Also available with a O/D tacked on the end (M46) if you have room for the extra length. Herb Kephart
Hi, I just updated my cad software & live mail and now when I tried to reply I was told that I have a problem with my "security tokens, and I should talk to an administrator". Anyone have any experience with this? The 305 pistons are Keith Black KB229 +.020 which is for a 3.756 bore, these are not racing pistons and are reasonably priced & off the shelf. If this message goes thru I'll try sending the rest of my original which included pictures. Pat
The information we had stated that the '31 Nash "8" rockers were 1.72 ratio, Chevy4 used 1.1 & 1.5, the cam spec sheet described 1.75 ratio. Measuring the original rockers stands agreed with 1.72 so that's what we used. The rods were 8.3 c-c, we could not get an OX-5 to measure. That length with the KB229 +.020 pistons came close to the original compression height.
Hi Pat, Welcome to the HAMB. Those are nice rods and even nicer rockers. You did a great job on the engine for the restoration. You came close on the rod length, OX-5's are 8.250" C-C. That's what Cunningham used for our rods in the 557 roadster. As far as the rocker ratio, I think the 1.75 was picked up off my sketch of the cam. That's the rocker ratio I used on the new head for the 557. The '48 engine used 1.5 ratio rockers. What compression ratio did you wind up with using the small block pisons? I considered using forged small block pistons in the 557 engine, but I think I would have been down on compression ratio from what dad wanted.
Thanks Curt, the math sez we had 10.5-1 comp. The agreement was to make it runable on pump gas with no intention of putting it in competition. I wish that I had time to degree the cam, I lined up the timing marks and was sure surprised when it reached 210 lbs. cranking compression. I redid my math 3 different ways and reached the same answer, makes me think the cam might have been advanced or it didn't have the duration we thought. I never got to hear it run the last nite I worked on it, that had to wait till the next day. Bill & Will sure deserve a medal for their heroic efforts. Looking back in time it's hard to remember all the problems we had to solve. My model "A" & "B" experience almost got in the way. Pat
This is a fascinating thread. Kudos to all of you that are working with these old parts. Just curious, how high do you spin these things?
I don't know much about that cam. When I bought all the parts from Duane, there were two cams, two heads, three blocks, two cranks, and much else. I chose the one cam because it was slightly longer than the one you have and I needed the extra length for the cam drive I was building. We degreed the one cam and assumed that the other was the same, but anythings possible. There was also a third stock FB cam that Isky ground getting us a little more duration and lift. He's the one that degreed the old cam for us, saying when he finished, "Yep it looks just like a Duntov" Ed claimed that Duntov learned about cam grinding from Winfield.
With a counterweighted 3 main crank 6,000 should be safe, I would imagine Curt's 5 main would go higher but you're still dealing with an 80 yr old block, a thin one at that. An old saying goes " if you don't want a race engine to blow up, don't start it". We kinda get lulled into false security by hearing Nascar engines in the 9,000 range for 500 miles, till you realize the investment in them. Pat
Curt & Pat, this thread is all the richer for having you both posting. Here are some pics of the engine Curt built for the 557 roadster Cast iron girdle 5 main billet crank designed by Curt built by SCAT crankshafts. Crank girdle assembly.
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