'58 - 348 Tri Power

Jim Sullivan

Well Known Member
Supporting Member 10
First side sounds, to me, that there is a miss or dead cylinder, second side sounds good, depending on your cam specs. But there are much smarter members here than me, so you should get some good feedback.
 

'37-4D

Well Known Member
First side sounds, to me, that there is a miss or dead cylinder, second side sounds good, depending on your cam specs. But there are much smarter members here than me, so you should get some good feedback.
Right! I was thinking that!
Fixes?
 

dm62409

Well Known Member
Supporting Member 12
Like James said check plugs first for proper burn, then I would do a crankng compression test on each cylinder to see if there is uniform pressure readings between cylinders. That being said, I do think your header pipe grouping on the passenger side could give you a bit funky sound as your merging pipes of 2 & 6, and 4 & 8, is not normal groupings for a standard firing order. Normal grouping for that side would be 2 & 4 and 6 & 8. You driver side is ok merging 1 & 5 and 3 & 7 grouping being normal for the standard firing order of 1-8-4-3-6-5-7-2. If the engines proves healthy with the testing, I really wouldn't worry about the slight sound difference of the passenger side exhaust.
 

'37-4D

Well Known Member
So, some of the things you guys are asking me to do, I can't..... such as the cranking compression test or running a scope!

Here what I was able to assess with the little I have in engine knowledge and tools:
When firing the vehicle from cold, everything seems fine!
The noise difference only happens once she is warmed up and I've run her for 10 mins or more.

From your input: l will definitely look into milder plugs!
Can you recommend one???

I pulled the plugs on the passenger side:
Passenger side plug pics, from front of motor to firewall (sorry for not knowing the numbers):unsure:

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'37-4D

Well Known Member
Those would be # 2 4 6 8
Looks like #6 is your problem.

Speaking to gent at the performance improvement store, there are no plugs lower than a dash 5. They only go up from there, 7 ,8 ,9 and all say racing!!!!
Please feel free to recommend a better plug.
If I run a leaner plug on the fouled one, since it's the only one, it'll be worst no???
I am going to swap #6 with #8, one of the plugs that is working in case it was a faulty one, and replace the one with a new one. See if #6 fouls again!!
Thoughts?
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
What is the casting number on your heads?? Those are short reach plugs that are to be used on the earliest heads[the ones without cooling for the plugs].James is right,number 6 is fouled out.Get someone with a compression gauge over there and check the cranking compression on that cylinder and compare it to another cylinder.The heat range on your plugs is fine as it it,judging from the other plugs.It could be just a bad plug
 

'37-4D

Well Known Member
What is the casting number on your heads?? Those are short reach plugs that are to be used on the earliest heads[the ones without cooling for the plugs].James is right,number 6 is fouled out.Get someone with a compression gauge over there and check the cranking compression on that cylinder and compare it to another cylinder.The heat range on your plugs is fine as it it,judging from the other plugs.It could be just a bad plug

872 block with 971 heads

I'm hoping for bad plug.

And will do a check on the cranking compression for that cylinder.
What are you thinking re: if the compression on that cylinder is off? and how would it be resolved?
 
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