The Stovebolt Site Forums The Shop Area Engine Shop 235 CAM ADVICE

I'm gradually working on swapping the 216 in my '51 3100 for a '58 235. Over 25 years ago, I had the 235 rebuilt by a local engine/machine shop and it is still sitting on the stand. I'm in no way a gearhead so I gave the shop freedom on any needed work on the 235 engine. Basics included +.60 bore; surfacing .060; new rings, pistons, rods, solid lifters, etc.

The shop did send out the stock cam for regrinding. I'm not sure if the cam was ground to specs requested by the shop or recommendations from Lunati.
Years ago, a mechanic told me that he thought the cam grind was actually not a good setup for the 235 as a daily driver.

I wanted to get some advice from experts out there while I still have the engine out. Would this cam be OK and if so, would any other modifications be suggested to make it run well? Or should I replace it now? If it is a cam I can use, what might it require for a carb, distributor, etc?

Specs of the grind are shown in the photo (it's all Greek to me!)

Thanks for any advice.

It's fairly hot, and will not do anything with a stock engine. Most 235 cams have significantly more exhaust duration than intake.
Stick or auto? What stall?
What axle?
What piston to head clearance @ TDC?

Rest of truck is stock - 3-speed on column and stock axle. Need guidance on how to measure "stall" or "piston to head clearance". I had one comment about low vacuum at idle

Thanks!

Tom, do you know whether you have solid or hydraulic lifters? Are you hoping for a smooth daily driver? Let's start with those 2 questions. If your stock camshaft was sent for regrinding, that could mean a few different things. The Lunati information could be a valid clue or it could just add to the mystery. Thanks.

Ah, never mind...I saw where you have solid lifters. Sorry...missed it earlier. Elgin makes a nice camshaft for the 235 with solid lifters...a copy of the camshaft used in the early Corvettes as I recall. I think it is E-293 but others may join with thoughts about it. Melling used to make one which I think was the CCS-1, but I don't know if it is still being made.

You can get lots of advice about that cam- - - -most of it will be worth exactly what if costs you to read it until someone actually puts a degree wheel and a dial indicator on the engine and plots a lift curve on the cam. The "rate of lift" is the important thing to consider, and that's impossible to figure with the information on the cam card in your picture. It also does not give you any clearance specifications, which can also be figured accurately by drawing a lift curve on graph paper. Lunati has always had a habit of grinding cams that are too hot for street use.

Until you can find someone to properly evaluate your cam with a hands-on inspection, anything you hear (even from Stovebolt) will be an "educated guess" at best. My educated guess (based on 65 years of building race engines) is that you need a less aggressive grind, or you'll need to do a lot more engine modifications and find a race track to play on!
Jerry

Thanks Jerry - your experience and comments are appreciated, although a bit disappointing. I'm a novice compared to most on this site and all of this information is quite valuable to my progress. I'm slowly realizing that finding a cam more suitable for daily driving and replacing it while the 235 is on the stand is probably the best option. I'll definitely be back seeking advice on that process.

One comment in your description concerns me- - - -"surfacing .060"- - - -if you're referring to milling the cylinder head, there's a possible problem. The edge of the intake valve sits right in the path of the combustion flame front as it sweeps across the surface of the cylinder head. The original head design has the valve sunken slightly below the surface of the head to protect that vulnerable edge from being burned by the combustion gases, so any head milling more that a thin cleanup cut to make sure the gasket surface is flat requires that the intake valves be recessed back into the head the same distance as the milling job. I was just given a freshly milled head that did not have the valves recessed after a deep milling job- - - -the valves only lasted a short time and the engine started missing and losing compression due to damaged intake valves. I can fix it- - -but the machinist who did the original job built in a fatal flaw.

You can check valve to piston clearance by getting a piston to the top of its stroke and using a pry bar under the rocker arm pivot shaft to push an intake valve down until it touches the top of the piston (gently) and measure the travel with a dial indicator. That distance needs to be at least .030" more than the "maximum valve lift" listed on your cam card- - - - -.060" is better. It's impossible for an exhaust valve to hit the piston due to the design of the cylinder head. I just rechecked your cam card, and it actually does specify adjustment clearances- - - -.022" intake and .024" exhaust. That's a bit wider clearance than a stock solid lift cam needs, so don't consult a factory service manual for valve adjustment info. The two cams suggested above from Melling and Elgin are excellent choices- - - -unfortunately, due to a shortage of "cores" to grind new cams with, they're "out of stock" at virtually all the usual parts suppliers. The guy who regrinds my cams is in his mid-90's, and he's on chemotherapy. I don't know where I'll get my cams once he's out of business!

Good luck!
Jerry


Edit: I collect, modify and upgrade 216's with more modern running gear like crankshafts, pistons, connecting rods, oil pumps, etc. Don't trash that old 216- - - -I might want to do a little horsetrading!

Jerry I realize this doesn't address the problem of recessing the intake valves, however the head gaskets available today are different. They're now the fiber type and are thinner, being .059~.060" in total thickness. I measured one this morning. The combustion area is ringed with a steel collar (could be magnetic stainless). Studying that gasket it is actually much better than the old imitation "perma-torque" alternative head gasket Fel-Pro made back in the mid 70s for the 235. What if Tom uses 2 of those head gaskets? If his head was in fact surfaced .060" and Tom used two head gaskets (with proper sealer between of course) he would pick up an additional .060". Yes, he only gains .0475" above the older type copper sandwich gasket, but it is still going to raise things and add space under the intake valves and the gasket sealer (if he uses the spray on copper stuff) will naturally add a bit of thickness also. Compression should be about what's normally expected I'd suppose (if the head had been shaved .060" and the gasket restored that amount). Your thoughts?

That approach is like taking aspirin for the headache caused by a brain tumor. It might relieve the symptoms temporarily, but it does nothing to solve the underlying problem. Shimming the head up with two gaskets will prevent a piston/valve crash and burn, but it will do nothing to resolve the valve edge erosion caused by exposing the valve to the flame front travel that happens 60 times a second at 2K RPM. If the fuel mix is slightly lean, that flame temperature can approach 2,000 degrees F. That's hotter than some parts of an acetylene torch flame.
Jerry

That cam is not really going to be fun. It has a relatively low lift and a lot of duration. Not really something I would call a very streetable cam. When I get home tonight I will dig out my old Clifford catalog. His cams were always more expensive but he had grinds that made sense, even if he exaggerated how much additional power they would make. I can at least give you some idea of what he was recommending. Me personally, I might want to see something in the .430 lift range with like 264 degrees of duration. That would be a pretty mild street cam. One thing you can do, is send the cam to Schneider Cams in San Diego for a regrind. He has two of mine as we speak for regrinding. Ask for Jerry Cantrell (he is the boss) tell him what you are doing, the vehicle, weight, use, transmission and he will give you a recommendation. they are currently running 4-6 weeks with their regrinds.

The new blue composite gaskets are pretty good. I don't believe the compressed volume is any different then the copper clad gaskets but they could be. You have raised the issue and now you have me curious so I will email felpro and ask.

On the .060 cut, usually you would want to sink the intake valves that amount when you get beyond .030. There is a rub though. Once you sink the intake valves, you have to shim the rocker stands the same amount and then use a lash cap on the exhaust valve, or sink the exhaust valve the same amount (which you really don't want to do because that combustion chamber is pretty bad and you will just make it worse.)

With that head, you should check the piston to valve clearance and that will require you to obtain a few tools, and make one tool, to do it correctly. First you will have to make a piston to valve stop tool. Then, you will need a dial indicator with magnetic stand, checking spring for the head, an extra head gasket, degree wheel, crank turning socket. You first determine absolute tdc, then you check piston to valve clearance starting at 10 degrees before TDC, 5 degrees before TDC, TDC, 5 after, 10 after, 15 after. Generally, the valve will be closest to the piston at 10 after. You are looking for like .070 or better clearance at the closest point.

This is a 261 my son and I were putting together. I had one cam on the shelf and it was pretty big. Not really right for flat top pistons and 7.5 compression ratio but he wanted to try to get to a show and so we stuffed the cam in and with the larger 50 powerglide valves, we had .023 piston to valve clearance which was entirely too close. So that is when we called Schneider, and Cantrell told us what he recommended, and I sent out two cams, a never used clifford regrind from the late 80s (way too big now even for me) and a stock cam. The new grind will be smaller in both duration and lift to solve the clearance problem. These are some of the photos to sort of show you the process.

Very interesting discussion - now I'm even getting more concerned about the functionality of this engine in the 3100. So Jerry, what you're saying is that the choice of cams won't matter since the valve recess will remain an issue?

My build sheet only lists, "Surface .060" and ""Valve Grind with Head Assembly". Is surfacing done if there is something like warpage or for performance modification reasons? Typically, can either or both heads and blocks be "surfaced" and does it matter which was done?

Unfortunately the shop was closed 20 years ago when the owner passed. This work was done in 1996. If it helps, the build sheet lists valve parts: 01192 Exhaust Valves; SBA562-9 J-Lay Exhaust Seats. No mention of Intake Valves or seats.

I will be curious to hear what they tell you, Mike. I contacted them a couple of months ago and they told me the blue one was slightly different but they stopped short of telling me what the differences were. Since then I bought one out of curiosity. They did say they had discontinued the copper sandwich gasket from lack of demand. As I said the blue one is better than the one they had in the mid 70s. About the only thing I remember good about it was all the water holes were ringed in metal. The gasket itself was nothing to crow about.

Jon, I refused to use anything but a copper gasket for years and years, right up till I had one fail three years ago. I still have 6 or 7 261 copper head gaskets. But I thought I had a cracked head three years ago, built up another head, swapped heads and put on the blue felpro. Sprayed a little copper spray on both sides, let it tack up, and not a single issue. Later, when we looked, the copper gasket had failed. The head was fine.

Tom, with .060 off the head, you are going to have to check piston to valve clearance with anything other then a stock cam, and even with a stock cam I would be checking. There is just no way around it. Surfacing should always be done with these heads, at least in my opinion. In the nearly 50 years I have been messing with them, I have never had one that did not need surfacing to get it flat. Generally, I am in the .010 range, but occasionally one is warped bad enough to need .020.

That being said, if you want to avoid all these issues, source your self another head and have it rebuilt without the heavy surfacing, stock or mild performance cam and you will be all set.

Tom as Mike and Jerry said that camshaft will not be good for street driving. It won't idle well, it is designed to perform well at an rpm range you may infrequently ever achieve and you probably will lose low speed torque if you use it...just my expectation on what I see there on your camshaft sheet. I don't recall Lunati ever making camshafts for normal everyday use. Those two cams I mentioned will provide a smooth running engine with more torque at lower rpms. For the 235 that's a really good thing. If you look at specs for the stock 235 you'll see a couple of variations produced more torque at lower rpms and that's what I like to see. The two aspects people admire about these engines is they're durable and they produce decent torque. In fact, you can see on this page the various production differences and the results: https://www.enginefacts.com/chevrolet235/ Focus please on the max torque and at what rpm that torque was achieved. You'll see a couple of variations reached maximum torque at 2000 rpm and then others required as much as 20% higher rpm to get there. More rpms usually means you're drinking more gasoline. Compare between 1958 and 1959-1962. There's more difference than might first meet the eye. GM just changed the camshaft to accomplish this higher torque at 2000 rpm and they discuss this on their Heritage Pages site.

As for resurfacing, the head will be resurfaced when the engine is rebuilt (as minimally as possible) to ensure it is flat and the block will also be resurfaced if it isn't flat. Not uncommon for both to need a bit of work, but .060" is on the high side, particularly if it was done to the head. What is being said is get that head off and see what compensating work was done (if any).

Some folks might remove metal to increase compression (enhance performance), but it all depends on what you're trying to accomplish and how much you know about that sort of stuff, because with this engine (as I think you're understanding) it might be a slippery slope. The 235 is an engine which was designed a long time ago and part of its limitations are a long wobbly crankshaft with only 4 main bearings, spindly piston rods that were not designed for any sort of high performance or abuse, siamesed ports and an intake manifold that breathes about as poorly as an asthmatic chain smoker. Aside from that, this is one of my favorite Chevrolet engines. But just like Barney Fife...there are limitations.

That's interesting, Mike. In the (I hate to admit this because it is going to make me sound old) almost 60 years I've been around these, I've never had a problem with the copper sandwich gasket but I had no end of trouble with those imitation "perma-torque" gaskets of the 70s. You would invariably see them start leaking midway down the head on the right side. First coolant and then oil and you knew you had about a month to pull the head and replace the thing with something better.

I consider countersinking the intake valves at least flush with the gasket surface of the head to be an absolute necessity, regardless of how much material is removed while milling the head. Back when there were plenty of stovebolt heads in the salvage yards, we would consider any head that needed more than about .020" milled off to make the gasket surface flat to be a boat anchor- - - - -just go buy a better used head to rebuild. As the supply of heads without cracks dries up, it's probably a good idea to do a little more machining to get things right the first time!
Jerry

Jon, me neither but I was always using a fresh copper gasket. Those are discontinued and while I used a brand new copper gasket, it was one I had in a full box of copper gaskets that was at least 30 years old. This time I thought, well I better get use to the new style gasket and so I jumped in and truth be told, not as fragile as the copper, less prone to bending and crinkling if accidentally dropped. Mind you, my 261 has forged pistons with a big giant lump that Bob Toros at venolia made me back in the 90s before he passed away so compression is pretty close to 9.75:1. Even at that compression, and the abuse I heap on it (I had that motor up to 5800 rpm last week at Beachbend Raceway Park in bowling green ky and not a single hiccup. So I think I will stick with what I can get in a fresh gasket.

Beech Bend- - - - -Dad raced there back in the late 1940's, when the "quarter mile" had four turns and a dirt surface! His body shop manager was his driver, and the car was a 34 Ford 3 window coupe running on Methanol and Hydrogen Peroxide!
Jerry

It takes us 13-14 hours to trailer down to beach bend. It’s one of the nicest and most historic tracks in the country and the only one with the spectator seating on both the pit side and spectator side under cover. They apparently salvaged what looks to be a 1940-1950s era baseball stadium seating and cover which makes it even cooler. The grounds are beautiful, the track is just terrific. The police left everyone alone driving in and around beech bend as long as you were not going overboard. We were there Tuesday afternoon through Sunday morning. One trip to Nashville for BBQ at Peg Leg BBQ, one stop at a distillery, my boy wanted to bring a little legal moonshine home. Pretty nice area to visit.

Depending on where you were in Nashville, you were only 70-something miles from my place. I'm close to I-65 near the Alabama state line- - - -been here since the early 1980's.
Jerry

I would have liked to said hello! We were right in the heart of Nashville with all the loud bars and music so loud on the street you can’t hear your self talk, lol. We drove the hour from bowling green to Nashville specifically to get BBQ at a place called Peg Leg Porkers. Stayed away from the honky tanks, did that last year. Once was enough, lol. So we were probably another hour from you.

In the late 1950's, my grandparents owned a small restaurant on lower Broadway, a block down 5th. Avenue from the Ryman Auditorium- - - -the Opry Corner Cafe'. Lots of the country music bunch at the time would drop in between sets on stage for a quick meal, or go across the street to Tootsie's Orchid Lounge for a drink or three. My aunt was the only pianist with a regular spot on the Opry, from the early 1950's to the mid-80's- - - -Del Wood.
Jerry

She was your Aunt? She's the greatest honky tonk piano player ever! I wish I could play Down Yonder or 12th Street Rag like her.

Yep- - - -that's how I got to hang out backstage at the Ryman Auditorium as a little kid with people like Little Jimmy Dickens, the Carter sisters, Stringbean, Roy Acuff, Minnie Pearl, and a few others. A few years later, I worked on Marty Robbins' 34 Ford coupe "Devil Woman" with the 312 Ford engine before he started driving a bunch of hotrod MOPARS at the Nashville Fairgrounds 1/2 mile oval track. I got to meet Jim Reeves at the WSM radio studios one day, and Tex Ritter rode the elevator I operated in the WSM building to his nightly radio disc jockey job in the mid-1960's. Growing up around Nashville in general, and the entertainment business in particular was "interesting"!

www.youtube.com/watch?v=2OY5iQUFTIQ

www.youtube.com/watch?v=idURSDVwIVE

Jerry

Gentlemen, please get back to the OP’s original subject. This chit chat belongs in the greasy spoon.

Thank you all for the extensive information you provided. I'm going to discuss it all with a friend who knows much more than me about engines to discuss the options you all presented. I'm sure I will be back on this topic in a day or so. Thanks again! Tom

Jerry - I think I sent you a private message.

PM back at ya!
Jerry

A couple more questions. I'm thinking of looking for a used 235 head and havig the valve seats done and head resurfaced at a local shop and install the new valve train from my rebuilt (and over-surfaced) 235 head. What year 235 heads would fit my '58?

Also should I locate a used cam and have it resurfaced ? It seems that new cams are scarce out there. My rebuilt 235 does have solid lifters and The Filling Station does have a cam listed for 235/261s with solids.

Thank you all once again

I have a machinist near me who can put the 261/Corvette profile on a good used cam, if he's healthy enough to run his machinery. He's 90-something and on chenmotherapy. He duplicated an Elgin E-293S cam for me a few months ago. Drop me a PM so we can have a private conversation without the PC Patrol getting upset at us. I'm shopping for my own cam grinding machine- - - -maybe I can start making those cams myself before too long.
Jerry

You may need more then just the seats done. What you are looking for is a head that ends in 848 and was cast in 57 or later. 56 was the first year for the 848 head but uses a smaller temp sender in the head. 57 and up use the same size. The head needs to be surfaced flat. Mine usually take anywhere between .005 to .010 to get the bowing that generally occurs with these heads out. A nice flat head, better chance of sealing the head gasket with no issues going forward.

Valve guides, these are old heads so I can't imagine you can turn up a head with perfect valve guides, but you never know. If you find a good used head with the typical valve guide wear, you should have the valve guides lined with bronze liners, and either stick with the stock O rings for oil control (they last about two hours before they fall apart. I am exaggerating of course but they don't last long) or have the guides cut for Teflon seals. Yes, you can still buy new cast iron guides but I just don't like pounding them in an out any longer. I broke a head a couple of years ago doing just that. Now, I leave them installed where they have been for 60 plus years, drill, line and finish.

Then comes your valve job. Skip installing hardened seats. Its an extra cost that is not really all that necessary.

Camshaft, a couple of places can do a regrind. I like Schneider cams in san diego because I have never had a failure with any of their cams. Send the used cam, as well as the lifters, even if the lifters are new. They will regrind the lifters so that they are compatible with the cam grind they did.

Cam grind, lot of debate on this. Lots like the stock 261 grind. I don't. Fine for a stock rebuild of course but you can do better. The 261 truck cam was used in the vette motor because GM already had it on the shelf. Like everything else with those early vettes, GM was trying to use what it already had on hand.

Talk to a good cam grinder. Tell him what you have and what you want to do with the motor. Like I noted earlier, I like Schneider Cams. The owner at Schneider is Jerry Cantrell. He has been at this for decades. Every time I call he himself actually gets on the phone with me, and I get treated like I am some big important customer when in fact I am just a local backyard driveway hobbyist. You will get an honest recommendation.

But before you go down that road, what Clifford cam do you have? It may be just fine. Can you post the cam card you received with the cam?

Mike, I think he already posted the cam card- - - -it's a very radical Lunati, not really suitable for street use. I like to use small block V8 stainless steel exhaust valves, and open up the head for the 1.94" intake valves made for the 1950-53 235 engines with the Powerglide transmission, and then pocket port the area under the valve to take advantage of the bigger valve OD. That puts the seat area into an unworn part of the head. I scavenge up every set I can find on Ebay. They show up there pretty often at pretty reasonable prices most of the time.
Jerry

See, my memory is fading fast, lol.

I do the same with my own heads. A good quality stainless small block chevy exhaust valve will work. I like Manley valves primarily because I can get valves with the stem back cut at the valve. That and in all the years I have used their exhaust valves, not a single failure. So I stick with what works. With these heads, every little bit helps. The 1.6 valves for the exhaust, yes I install them but you do have to clearance the combustion wall a little and hog out the bowl a bit to make use of them. Same for the powerglide valves.

I don't own a flow bench or have access to one. Would love to of course but no dice at the moment. But I have always been curious as to what effect larger valves, larger valves and a little hogging out, back cut valves, other stuff actually has on a 235 head. If I ever get access to a flow bench, I would love to sort some of this out.

I cheat- - - - -my "flow bench" is the "blow" side of a shop vac, with a water manometer connected to the pressure hose. Lock the valve open at max cam lift with a shaft collar and no spring, and pressurize the port, then adjust a bypass valve in the pressure hose to get a few inches of water indicated on the manometer tube. Once the first port sets the standard, check and compare all the others to the baseline it sets. I think my total cost was less than $100.00. With the right setup, both intake and exhaust ports can be measured.

www.ebay.com/itm/314715194529?

Jerry

OK - As suggested, I made an attempt at measuring valve to piston clearance. The engine is on a stand without flywheel and the timing cover is still on but I brought cylinder #1 as close to TDC as I could. I measured the movement of the #1 exhaust valve from closed to where it wouldn't move any further which I'm assuming is touching the top of the piston. The travel is almost exactly .10". According to a previous post, the travel should be between .030" and .060" more than the "Maximum Valve Lift". The Cam Card photo is below. Is the Maximum Valve Lift the same as the "Tappet Lift" of .050" shown on the card, or should I be using "Lift at Valve" of .417"?

If it is Tappet Lift, it looks like adding the range of .030 to .060 to the .50" would give me .080" to .110" and my .100" would be within the range. I hope this is good news and might show that the head wasn't over surfaced.

Thank You all

I don’t mean to be critical here but you need to reread my earlier post very carefully and take a good look at the photos. You can’t make “an attempt to get close to TDC” to measure piston to valve clearance. A mistake here will cost you a lot. Bent push rods, bent valves, time effort, gaskets, money.

There is no way to shortcut this. You have to use the correct tools to determine true Tdc and be able to accurately get to 10 before and 10 after TDC. Btw, the intake valve is closest to the piston at 10 degrees after TDC. So you have to accurately measure with a dial indicator and degree wheel to sort that out. No other way to do it. This is what is required with a big cam and stock flattop pistons without valve reliefs.

The place to measure the piston to valve clearance will be at the top of the exhaust stroke. Watch the exhaust valve spring as you rotate the engine in the normal running direction, and as it relaxes fully, the piston will be very close to the top of the cylinder. Then you can either probe into the spark plug hole, or use some other method of assuring the piston is at top dead center of the exhaust stroke like using a borescope, or watching the ball and pointer in the bellhousing window.

Once you're sure the piston is at the top of its travel, use a long, heavy screwdriver or a pry bar to push the intake valve down against the top of the piston. Stock stovebolt cams have very little or no "overlap" where both valves are open- - - - -the exhaust valve is almost fully closed before the intake begins to open. More radical cams, like the one you have, will probably start opening the intake a bit sooner- - - -maybe even a LOT sooner. The exhaust valve is angled so it simply cannot touch the piston, so you only have to be concerned with intake valve to piston clearance. As long as there's at least 1/16" or more of free movement before the valve touches the piston at the top of the EXHAUST stroke, you're good to go!
Jerry

This is a point in engine building that requires extra care. An error here, even if you're just turning the engine over by hand, can result in bent valves and/or pushrods. Cams with earlier opening intake valves can hit the piston before TDC.

So If the engine is assembled with the head on and pushrods installed, back off all the adjusters a good 0.080 except the one you are checking. Then with the degree wheel velcroed onto the front damper and some sort of pointer rigged up, approach TDC carefully watching the degree wheel and pushing the intake valve down with a suitable lever. With the cam listed on the card you may find minimum clearance at about 10 deg. BTDC or some similar number. If so, stop there!

At 1 deg before TDC you will have 0.050 valve lift minus the running clearance, if that's included in the figures. A recommended minimum is 0.060". So keep checking as you approach TDC to ensure you don't go below that. My engine has 0.050 and I got away with it but that leaves little room for error in thinner head gaskets, future head resurfacing etc. My cam is ground 4 deg. advanced which adds to the problem. Yours is ground 0 deg advanced and I would not use an offset key to change the cam advance; nor would I attempt to raise the compression ratio to get a little more bottom end. Change cams or just live with the lack of bottom end torque.

DragSix - I totally welcome your critical comments. I am learning a great deal through these posts and appreciate every bit of feedback. Since the engine is on a stand and the cam cover is still on, I didn't have an easy reference for TDC. As shown in one of your photos, I did put the dial indicator on the #1 Intake valve keeper. I leveraged the rocker arm and valve downward while turning the engine with a bar between 2 bolts placed in the balancer. I rotated until the dial indicator registered the smallest reading between valve and piston (.099). Should I align the marks on the cam and crank gears and use that point as true TDC?

I was taking measurements alone, with stock springs and no degree wheel so my accuracy may be off. Also, I didn't know about backing off adjusters. I plan to enlist a helper, buy a degree wheel and also try to find a test spring so I check measurements once again.

Thank you all
Tom