SteveMelchiorre Posted July 23, 2008 Report Posted July 23, 2008 As this is my first post I'm currently in the process of restoring a 1952 B3B 1/2 ton in Vancouver British Columbia. I bought her almost 7 years ago. At the time she was in rough running condition but good enough for the monthly trip to the lumber yard or city dump. I recently had the brakes completely overhauled and while the mechanic was at it I asked him to Helicoil the #3 sparkplug. The previous owner had cross threaded it and on occasion the sparkplug would shoot out of the hole! Here comes the bad part...when I picked up the truck it was running a bit rough and I thought that the timing might just have been out a bit so I drove her home and she sat for another week. The following weekend my kids (3 year old twins) and I tried to adjust the timing but it began to run rougher and rougher and eventually would not start at all. After a day of trying everything I discovered that there was no compression in the #3 Helicolied cylinder. So I have 2 questions.... If all cylinder were good what should proper compression be? (my other 5 cylinders all register 60psi) ...and what could this mechanic have done to cause this? I'm having the truck towed back to his shop tomorrow morning and I'll post updates. Steve... ..btw - Nice to have found this forum. Quote
Tim Brown Posted July 23, 2008 Report Posted July 23, 2008 The spark plug hole would have to be drilled out and tapped for the heli-coil. Some of that material may have got under a valve. Quote
Merle Coggins Posted July 23, 2008 Report Posted July 23, 2008 Also, there's not much clearance between the head and the tops of the valves under the plug. If he used a longer helecoil, it may be interfering with proper valve operation and could have bent a valve or two. For your sake I hope I'm wrong, but I had to state the possible. Merle Quote
Guest Kuster13 Posted July 23, 2008 Report Posted July 23, 2008 I have a spare head you could have. Tom Quote
SteveMelchiorre Posted July 23, 2008 Author Report Posted July 23, 2008 Thanks for the info. Tow truck is on the way... What should normal compression be if all cylinders were working correctly? Steve.... Quote
Don Coatney Posted July 23, 2008 Report Posted July 23, 2008 What should normal compression be if all cylinders were working correctly? Steve.... That is somewhat dependent on the general health and compression ratio of the engine. Quote
Guest Dave Claussen Posted July 23, 2008 Report Posted July 23, 2008 It might be the type of helicoil that was used. Not all thread repair helicoils are the same and some types are not going to form a tight seal and thus would allow for the escape of compression around the the insert (not around the spark plug if you see what I mean) The size of the repair helicoil could also be a possible area of compression loss. If the thread were a "loose" fit, it could compromise your compression also. Does the plug fit snugly with no play or wiggle just before you tighten it up to torque specs? If not, that could be your problem. Also if the helicoil turned in further after the plug bottomed out on it, you could have the situation that Merle described. If it were me, I would definetly be suspect of the helicoil. We use thread repair inserts at work and I'd be really hesitant to use one to do this type of repair. Just my 2 1/2 cents worth. Dave Quote
norrism1 Posted July 24, 2008 Report Posted July 24, 2008 Steve, They may have not used a spark plug Helicoil to repair the head. At Advanced Auto Store: Part Numbers that may work: R533414 - Heli-Coil Spark Plug Thread Repair Kit R532614S- Heli-Coil Spark Plug Thread Inserts: Short Reach R532614N-Heli-Coil Spark Plug Thread Inserts: Normal Reach Might want to find out if they used a "spark plug" Heli coil insert! Quote
SteveMelchiorre Posted July 25, 2008 Author Report Posted July 25, 2008 Thanks for all the advice. I spoke to the shop that is working on my truck today. They said that the mechanic that did the work was not in yesterday or today ~but~ would be in tomorrow. I'll be sure to bring these points up then. Steve... Quote
5.9diesel Posted July 30, 2008 Report Posted July 30, 2008 Don Coatney: is that the last page from a vintage Motors manual? i just did a compression test on the 50 b-2 I might buy, and cylnders 1,2,3,4, and 6 were 95psi, and cylender 5 was 89 psi. Quote
55 Fargo Posted July 30, 2008 Report Posted July 30, 2008 Don Coatney: is that the last page from a vintage Motors manual?i just did a compression test on the 50 b-2 I might buy, and cylnders 1,2,3,4, and 6 were 95psi, and cylender 5 was 89 psi. 5.9, these are all fairly consistent readings, 100 to 110 is usually best, but if they are all 95, not so bad. The #5 cyl is a bit off from the rest, possibly sticking/leaking valves, a bit of a head gasket leak in this area, or rings that are more worn on #5. I had a lower reading on #5 cyl when I first got my flattie going after several years, it still runs very good, my reading were a little higher than yours, 100 to 110 with # 5 being the 100..........Fred Quote
55 Fargo Posted July 30, 2008 Report Posted July 30, 2008 100 lbs, is considered acceptable, or even less if they are consitent with each other. 60 lbs is on the low side. Any idea how many miles onthis engine? Have you been running it very long? Too bad your so long away from my location, I could hook you up with another engine in short order.........Fred ps Bill W from our forum also lives in the Vancouver area, he is very knowledgable on Mopar flatheads. Quote
5.9diesel Posted July 30, 2008 Report Posted July 30, 2008 rockwood. im thinking it might be the valves. it ran well, but had a little thup thup in the exhuast. it ran smoothly, but maybe the exhuast valve is a little sticky or misadjusted. Quote
5.9diesel Posted July 30, 2008 Report Posted July 30, 2008 this is only the second time ive run it. it belongs to my neighbor but im thinkin of buying it, and since i know him, and were both mechanics, he is generously letting me check it out. the numbers on my guage are kinda close, i know they were not below 90, but it could have been 100. i dont know. Quote
Don Coatney Posted July 30, 2008 Report Posted July 30, 2008 Don Coatney: is that the last page from a vintage Motors manual? Yes it is. Quote
5.9diesel Posted July 30, 2008 Report Posted July 30, 2008 ive got one for cars that goes up to 53. it doesnt have the truck specifics, but it gives me the general idea! Quote
Don Coatney Posted July 30, 2008 Report Posted July 30, 2008 ive got one for cars that goes up to 53. it doesnt have the truck specifics, but it gives me the general idea! I believe that page came from a 1953 MoToRs manual. I have several all the way up to the 1980's Quote
5.9diesel Posted July 30, 2008 Report Posted July 30, 2008 yup. mines a 53. I got mine for free from the local transfer station. they have a little concrete 1 room building, and you can take and leave books as you please. my friend is restoring a packard, and it helped him out too! Quote
SteveMelchiorre Posted July 30, 2008 Author Report Posted July 30, 2008 Thanks for the info Rockwood. Currently the Odometer reads 69k...but I'm not sure of the exact mileage. I bought her 6 years ago from a "kid" out in the boonies. At the time I was driving an Audi A4 and that car could not make it down the fire roads up in the mountains where I pulled this truck out of! Since I brought her home I've only used her for the occasional Rona or City Dump run but this summer I wanted to make some more progress on the restoration. I'm not a purist when it comes to this but I would like to keep the original engine if I can. If indeed I am only getting 60lbs of Compression on the 5 working cylinders I guess I'm looking at having the engine overhauled. What should I be expecting? Steve... Quote
55 Fargo Posted July 30, 2008 Report Posted July 30, 2008 If you do the R and R, about $2500.00 to $3500.00, try and find a decent used engine for now, you can swap them and have yours rebuilt whenever, that way you can drive the truck.......fred Quote
Fernando Mendes Posted July 31, 2008 Report Posted July 31, 2008 Steve,lack of power in an engine is sometimes caused by poor seating of the valves in the valve seats which allows the gases in the compression chamber to escape into the intake or exhaust manifold.Through the use of a cylinder compression gauge one can readily determine which valves are not properly seating.You may check too the screws and nuts of the cylinder head, principally if have presence of water and oil leak.Tighten them with a tension wrench in a sequence of L-Head six engine.For example in an L-Head 4(Jeep) engine screws to 65 to 75 foot pounds and the nuts to 60 to 65 foot pounds.Goog luck. Quote
SteveMelchiorre Posted July 31, 2008 Author Report Posted July 31, 2008 Thanks again for the good info. I'm having a hard time reaching the garage that has my truck for an update. They've had her since last Friday! I'll update when I know what is going on....but thanks again. All this info given me more to go on when I speak with them. Steve... Quote
SteveMelchiorre Posted August 1, 2008 Author Report Posted August 1, 2008 Update! I finally spoke to the shop that has my truck. They confirmed that something got into the #3 cylinder and bent a valve and they will replace it no charge. .... so I asked them since they have the head off wouldn't it be wise to go ahead and replace all the valves? They discouraged this idea saying that if there was better compression on top it might blow out the rings. -- Is this True or False? Alternately they recommended pulling the engine and completely overhauling it. Here's where I need some advice. I am somewhat mechanically inclined but I have never pulled an engine out of any vehicle. Can someone give me a basic idea what I would be getting myself into if I took this on? Steve... ~ and when I get the quote I'll post the amount for comments.... Quote
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