I am rebuilding a 1949 Chevy 4408 1 1/2 Ton flatbed. I replaced the blown up 235 with a used 1962 235. I saw the engine start and run with no problems before it was pulled from a 1959 pickup. It ran fine. I have installed it with the 1949 clutch housing and 4-speed transmission. I have kept the 6 Volt Starter and coil. I had the starter rebuilt with new fields put in it. The coil checks out OK. I put a new Optima 6 Volt battery to get 1090 cranking amps. I confirmed the #1 cylinder at TDC with a screwdriver in the plug hole and set the distributor so the needle aligns with the ball on the flywheel according to the 1949 Factory Repair Manual. The wires read around 9K Ohms and the coil wire reads 6K Ohms. Plugs are R43. Points are set to .018" and plugs are gapped to 35. Compression reads from a low cylinder of 95 to 2 reading at 120. I have confirmed that the battery cables on both sides are good. I have even tried using heavy duty jumper cables to augment the connections between the battery and starter motor to confirm the installed cables are not the problem. I replaced the coil to distributer lead from the coil with a new piece of 16 gauge wire. When I hit the starter it turns rather slowly and balks almost to a halt when it comes up on compression on some cylinders. I pulled the starter and had it load tested and it has been checked out fine by 2 shops. I rebuilt the ##### YF 2100 carburetor. I have only been able to get it to start 3 times with considerable cranking. Fuel flow to the carb is fine and I have even tried to use a shot or two of starter fluid to make sure it was getting something to burn. Once it starts it runs fine with only a slight miss periodically. If I turn it off, it is hell to start again. It acts like it doesn't have any spark, but if I pull a plug and check it, it has a good spark. It acts like the battery is dead, but it is showing 6.35 Volts and drops to about 5.5 when I start cranking. Is there some difference in setting up a 1962 235 versus a 1949 such that the instructions for setting it up using the old book is causing me some problems? I could swear it sound like it is not timed correctly. I can't use a timing light because I can't get it to start so I am using the book's instructions to set up the basic timing. What am I missing? Bossman 1949 Chevy 1 1/2 ton 4408 flatbed
Wierd ; Try retarding the dizzy by hand whilst you're cranking it , it only takes like 1/8 turn to make a _HUGE_ differance .if it's too far advanced, the cranking speed will increase as you retard the timing . Go to Deve's most excellent site and follow the valve adjust instructions as tight valves (I find them in EVERY engine) will greatly hinder starting , moreso on hot or 6 volt applications . Get a vacuum gauge and plumb it to the intake manifold then watch it whilst twiddling the distributor , adjust the timing for the highest _steady_ vacuum reading , this only after you've adjusted the valves tho' . Disconect the vacuum advsnce line ad see if that helps as there shouldn't be any vacuum at that line until you open the throttle . Wish I was there to help sort it out . -Nate
Nate's right about these old 235's being timing sensitive-I learned this a long time ago. Will it fire right up with a push? If this is not an option here's something you could try: disconnect your main feed wire from the starter battery post and use a temporary 12 volt battery. Disconnecting the main feed wire will protect your bulbs and gas guage and 12 volts won't hurt your starter. Run a jumper with a resistor in it from the battery to the coil and give it a try. If this fires it right up it's definitely a cranking speed problem. Just remember that the aforementioned valves and timing could be contributing to the slow cranking.
Thanks for the great tips. I have been out working on a movie set the past few days. I just purchased a new coil for it and am going to install new R45 plugs tomorrow before I beat on it any more. Then I will try all the stuff you guys recommended. This site is great about getting terrific ideas for these old trucks. I am also looking seriously at the engine listed a few messages above and converting over to 12 volts if I have to. I could go either way but would prefer to stay with 6 volts just to stay as clost to original as I can. Great idea to disconnect the vacuum advance. Unfortunately I don't have the option to push or pull start it because the brakes are not working yet... I only have the emergency which needs some adjusting. What is Dave's web site? I would like to check out the Valve info he has. I still feel it is out of time and am thinking if might have been assembled with the timing gears off a tooth. Would it still run like that? It might explain why it seems to want to lock up when it tries to ignite at low speeds. I have the 1949 shop manual and am planning on running a timing check tomorrow, as well, just to see where it is at. I hope the 1949 manual applies to the 1962 engine. I will let you know what turns up. Bossman...
RE: 235 Hard to Start - Problem Sol I finally figured it out. After changing the coil and putting in the proper plugs it still was acting like it was out of time. I pulled the rocker cover and tried to check the valve timing according to the 1949 book. That's when I realized the 1962 235 had hydraulic lifters instead of solid. They could be seen bleeding down after I shut it down. I checked the tappets and found not a one of them was even close. Most were showing lash of 1/4" or more. I guess once they pumped up they were OK, but the valved were opening way too late and closing way too early. I readjusted them according to some recommendations on Stovebolt.com and it cured the whole issue. It no longer sounds like it is trying to lock up when it tried to ignite gasoline. It turns over at the expected speed and, once I was able to properly set the distributor it fires right off when warm with out any choke and idles smoothly at 450 - 500. Thanks for all the great ideas on where to look. It really helped.
RE: 235 Hard to Start - Problem Sol Cool beans ! . It is very important to correctly adjust those hydraulic lifters so the cam doesn't get ground flat ~ engine running and warmed up , loosen each lifter until it just begins to clatter then carefully adjust it to zero clearance , this is when the ' click ' stops . Some books will tell you to adjust to zero lash then add 1 - 1/2 turn more , this is _WAY_ too much preload . Have fun and remember to do a bunch of hot oil changes with detergent multi-vis oil to clean all the sludge out of the engine that will otherwise clog up your liters . thinner oils will make those juice lifters work better . Synthetic oils with clean all the crud out in a hurry so don't run it onver 50 ~ 75 miles the first time you use it . -Nate
RE: 235 Hard to Start - Problem Sol Thanks again, Nate, for all the advice. When I pulled the pan I was amazed at how little crud there was, so I guess the guy was on the up and up when he said he had rebuilt the engine a couple of years ago. If only he had set the valves properly. I have gone out now three days in a row with the engine dead cold, pulled the choke and had it start in about 2 revs. I plan on working on the generator and regulator this weekend to get them up to snuff so I can keep the battery charged. Then I will pop off the rocker cover again and do a final set once it is nice and warm. I will try to snap a couple of photos of my work in progress to send along later.
RE: 235 Hard to Start - Problem Sol Cool beans ! always nice to get a good engine . Enjoy and post some pix of engine and truck when you get a chance . -Nate
RE: 235 Hard to Start - Problem Sol I found it imposible to adjust the rockers with it running. In newer model chevys that have the center adjustment nut, what you suggest is true, but my 235 rockers are adjusted on pushrod ends. I found that with the side cover removed to see the hyd lifters to confirm movement I was able to set without engine runing. I loosened the adjustment until there was lash. Then while turning the pushrod to feel freedom with one hand and the other hand turning the adjustment screw until I had achieved zero lash. Then screw in another 3/4 turn and lock. You should see the pushrod compress the lifter about 30 thousands off the retainer wire. TERRY>>>>
Nate - Can you give us the address for "Deve's most excellent site and ... valve adjust instructions" you referenced in your post. Thanks. Mike M '27 Chevy '41 John Deere B '49 GMC FC-150
RE: Deve's Site Uh ~ you asked me , the total computer duus the wrong question ~ even _I_ don't know how tofind it , he's over on the yahoo old gmc trucks list and asked me to write this up for him . I dunno how to keep a copy of it either , doggone it . I am sure some one here can help you out , I *think* it's on SpeedPrint , what ever that means . -Nate
RE: Deve's Site - the address Nate - I got enough info from your post to Google Deve's site. Here's the address for all interested: http://www.speedprint.com/Deves50/deveshowto.php Mike M '27 Chevy '41 John Deere B '49 GMC FC-150
RE: Deve's Site - the address _THANK_YOU_ Mike ! . I knew you guys would come through on this . -Nate
6 volt systems don't have the snap of a 12 volt system. They generally take twice the amperage of a 12 volt system. A drop of one volt can make a huge difference in starting ability
Setting Valve " Lash " This refers to the gap between the stem of the valve and the tip of the rocker when the cylinder is @ TDC , where you adjust it . If there is no space , the valve won't seat correctly and will overheat , warp & burn in a few hundred miles . the valves and seats in our old StoveBolts are -SO- well made , the engine will run albiet poorly from these " tight " valves , so simply adjusting them will usually make a tired old engine you think is junk , run like new again . Some , very few , 235's have hydraulic lifters so there is -no- lash at all , these are correctly adjusted by ear , never by the ' 3/4 turn after contact ' method as the oiling sysytem in a 235 isn't up to the high pressure & volume needed to properly " pump up " hydraulic lifters.... So you run the engine and turn the adjuster untill it begins to click then you turn itthe other way just untill the clicking sound stops , it's very simple even thogh the box end wrench keeps hopping off the rapidly bouncing rocker arm..... In ALL cases , you want to be adjusting thre valve lash when the engine is hot , having reached full operating temperature . No one said being a vintage mechanic would be easy . I hope this helps...?
Would this same advice hold true for a 228? It will start with a shot, and run smooth as a dream, but don't shut it off unless you mean it. I've had it all warmed up hoping that would make a difference, but it doesn't. The in-line fuel filter I put in front of the rebuilt carb but past the new fuel pump that is after the relined tank will never hold more than half a filter full of gas. It will shoot gas out the end if I take it loose from the carb, so everything up to that point works, and like I said, when it's ruining, it does great. I'd just like to avoid mounting a spray bottle of starter fluid over the carb with an inside-the-cab push button next to the start button... ..although...
No ; GMC engines don't have hydraulic lifters so you don't adjust them by listening , you warm up the engine and adjust them one cylinder at a time , if your engine has over 90 # per cylinder compression and it needs QuickStart spray to get going again , you need to adjust the valves 1st. then set the dwell , timing and so on , in that particular order . Be sure your spark plugs are gapped to .035" , most come way too closed up These engines should always be very quick starters so if they're not , something basic is amiss.... Look up valve adjustment on Deve's Antique Truck page over on Speedprint , there's a link to it somewhere in this board .
Many thanks for the advice! I'll follow it and see what I see. The quick start and relatively quiet sound have given me hope, as did what you had to say about the 228. The "basic" thing has been driving me kinda' nuts though. It just twernt makin' no sense! It might have been God's way of sayin' "If you drive this truck one more time without redoing the front end first, I'll park it in a tree on you!" (It's only set in a field since mid 70's(?)) Anyway, THANKS FOR YOUR TIME! That's all caps, because hey, I really appreciate it! I'm new to this, but with good advice, I can get-r done!
