Yep 351 exhaust valves. I think they had to be shortened and spark eroded hole for spring retaining pin. Don't have dimension details at hand but will check my archives
I was told that the 455 Olds from the 70s we're the cat's meow. Just the exhaust and a little guide ream, and they were using the retainer and one valve spring; but you have to be careful with springs on the old cam. I have custom lifters, like the old Ford Y block so a lot more surface. Have fun, hope this helps Sent from my SM-G930V using The H.A.M.B. mobile app
Thanks for that; these look like a really good upgrade from the factory valves: http://www.jegs.com/i/Edelbrock/350/9318/10002/-1 Just 0.030" larger at the valve head and 0.70" longer overall length. with stems at .341" diameter they will be ideal for heads (like mine) with valve guides which are in a poor state. Should be possible to use the Olds valve caps and keepers too.
Couldn't you go out to 9mm then use some uk metric valves? Those costs will mount up bringing in valve, collets etc from the US
Yes, those valves do look like they will be a bit spendy by the time they arrive in the UK; but it does look like I can use them pretty much as they come. I need to search the interweb for a proper engineering drawing of these Olds style valves to be sure, but I think there's a fair chance that SBC keepers and valve caps will work with the Olds valves. I have at least one complete SBC head in the workshop that's a scrapper, so that might save me a few beer tokens.
Ok so I'm having a panic attack. I'm boring out to 3.876. Way to far, I get it. I have to go out that far anyway because there is a deep rust pit in number 1. Problem is now I don't think there's enough meat between 1 and 2, 3 and 4 to seat a head gasket. Does anyone know the minimum distance I need to get a gasket in there? I am in contact with a gasket guy who needs that measurement and I'm nearly embarrassed to tell him... The gap will be reduced by 4.7mm 0.1885" if they get bored central I haven't had the block back yet to check. I did ask to have the cylinders offset a tad, if possible. Don't know the outcome yet. Or I fit liners and get back to standard pistons Thing is, if these walls end up so thin, the gasket is the least of my problems. Herb, I know you have done this in the past. How did it work out for you?
One of the things that Herb did with his speedster engine was to mill the head and block flat and groove the block for copper rings- that way he didn't have to use a gasket. He can explain it much better than I can, but that's the basic idea.
Head bolts... I much prefer to use studs and nuts. However making them at home would end up with cut, not rolled threads and then there's the choice of material, treating etc. Has anyone switched to studs? If so any details?
This may be in here somewhere. but it is getting to be a pretty long thread. So I thought I would ask if anyone is oiling their rocker and i so, how? On my 26 Dodge OHV conversion I put a tube in the rocker cover with holes drilled to squirt oil down on the rockers. It has roller rockers with stud mounts. I think that might be a good thing to do to the Chevy. Need to deal with the drain back. But that is doable. Thoughts? Suggestions?
Not quite at this point yet with my engine build, but I will be using home made studs for the cylinder head. When I've made studs for other vintage motors where there isn't an "off the peg" parts supply, I've just screwcut the threads onto British Standard EN16 round bar. This is general purpose high tensile steel that machines quite nicely -Google seems to give ASTM B473 as the US designation (or maybe equivalent) to this steel. I too would like to use something a bit more advanced than a piece of oil soaked felt draped over the rocker gear. The design of the "top" of the '28 head really doesn't seem to help though. There are effectively pockets that the valve guides, valve stems, and the bottom half of the springs sit in. These pockets look like they would completely fill with oil with any constant lubrication solution -I am trying to get enough of the "straight" 216 stovebolt rockers together to use on the build of my 4 banger. If positive lubrication is to be used, I think that the valve guide top would need to be machined to take a modern valve stem seal to stop the car disappearing behind its own smoke screen once it's running
I notice that my head has umbrella seals on the intake valves. I wonder if that will suffice for this?
Stueee, I used B-7 threaded rod for my DB engine. I think it's 4340, has worked great for about 10 years. McMaster-Carr sells it in most thread sizes. I'm a retired millwright and we used it for all of our rods on hydraulic presses and porta-powers.
When I was actually working for a living I single pointed 4130 HT plenty of times. Maybe not the best answer but very serviceable in real life.
So I just noticed that the rocker assemblies that came with the '25 Olds head, will not clear the rocker cover. So I guess this means I make a new cover. Or try to find a cool looking cover that is close and make an adapter. Which I like better. But it's a pretty short valve cover. Not sure anything out there can be made to work. I might be able to section something. I added 1.4 inch to the '26 Dodge cover. Maybe the left over parts can find a new lift on a Chevy. The 360 MoPar cover is not wide enough. 368 Lincoln is no good. Maybe a BBC cover could be made to work. Or a 351 Cleveland or 460. Something with staggered valves would be wider.
Rich, This is the cover on the Spurgin Giovanine engine- If I remember correctly, copies were made, but not available. Shouldn't be too hard to copy/make your own version, though
Looks like it has a plate laying between the cover and head. Which is what I thought would be necessary. I might trim mine to fit a little more. And I think mine will be thicker so that I can use hold down screws on the outer flange instead of through the center.
How about one of the repo covers available for some of the T overhead conversions? Langs Old Car Parts has them for Roof, Frontenac, and Rajo. I have a Frontenac I'm adapting to my 153 Chevy. They are pretty wide. I can compare it to my '28 Chevy of you like.
This is the rocker assembly that came with the Olds head. As you can see, it is quite different from the Chevy rockers. I may decide to shorten up the stands a little. The rocker angle looks like it could be better. But the lift is so small that I don't know if it's worth worrying about. The whole valve and side cover deal on this motor is goofy anyway.
I went with the 4340HT for the studs Remember that they are 1/2 -12 on the block end, and I made the top 1/2-20. Wasted the stud away to the 12 TPI minor diameter with a large radius transition to give the stud some "stretch" between the threads. Also, did the 1/2 inch felt pad thing . Squirt oil before taking the car out and no problems. Bent up and welded cover from 1/8" 6061 Aluminum Sorry now that I sold the car too cheap to a bullshit artist who only wanted to "flip" it.
Nice looking cover. I think I am going to shorten a BBC tall steel cover. I want to use the side plates since I plan to spray mist the rocker area.
Pretty pleased with things The block is now John Deere green, just needs a skim. The head is all done. The crank and rods are now matched After boring out to fit model a pistons I found a really sound gasket maker who thinks he can get the gasket to seal, weather Or not the cylinders overheat is another matter. I'm ploughing on with this block regardless I've also bought a just-in-case engine... I feel kinda stupid now taking it out so far but if it works I'll be extra pleased Just look at those cylinder walls. !
No need to feel stupid, it's not for a daily driver and who dares wins! I'm still trying to decide which way to go with mine. A machinist mate has just restored a boring machine and is testing it on a scrap block in the next couple of weeks. He reckons that if I overbore for A pistons the bores can be moved apart a bit to improve the gasket area somewhat, My block has very worn bores but almost rust free in the water jacket which is good. Boring out and fitting liners to use '28 Chevy repro pistons would keep the wrist pin offset correct but cost much more and it seems silly not to get a little extra performance for all that work.
It's the start of the slippery slope. Give it 6 months and you will be cutting the firewall to fit a 3 port head
Yup! Spread the bores, and THEN bore. Don't make one of the bad spots in the design worse. See the two small holes in the left side of Andy's block head surface? Drill them in any block or head that you use. Helps cooling of #4 cylinder. Use head gasket for pattern. All head gaskets made after '28 had those holes. Herb
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