Engine not running right when warm

[willie1957]

Hey folks,
This is my first time posting on this site however I've been lurking in the shadows for quite some time. I thought I would tell of my recent experience with my truck. Perhaps it will be helpful to someone else in the future.
I recently purchased a 235 and put in my 56 pickup. The 235 supposedly had about 1000 miles on a rebuild that had been done 5 or 6 years ago. Anyway, it's been running good for me at start-up but once warm, it looses about 200 rpm at idle and just does not run right.
I've searched the threads here and checked everything that was suggested for similar problems but still had the same problem. I found the valve adjustment procedure as posted by Nate and decided to give that a try. I was hopeful and somewhat optimistic that a good valve adjustment was what the ol' boy needed. Saturday morning I took it for a good drive to get it good and hot, limped it home and got down to business. I'm very happy to say that now it runs fantastic!
I did before and after compression tests and went from an average of 80 lbs compression to over 100 lbs. I followed Nate's suggestion of .008 for the intakes and .020 for the exhaust valves. Yea, it's a little noisier now than before but I remind myself of Nate's words of wisdom, "A noisy valve is a happy valve" so I'm definately willing to live with it. One thing I would add is to suggest to cover the radiator with a big thick towel to save yourself from some nice burns. (I have a couple real good ones!)
Anyway, I want to thank all of you that post and especially Nate for providing what I needed to get my truck running right. Since I'm new, I thought I would add a few pics of my truck. I bought it last summer and have enjoyed the heck out of working on it. The biggest thing was to repair the horrendous nightmare of a sun roof having been put in. I have also rewired it from front to back and removed (and sold) a BBC 454 and gone back to an original six. I have also put in new bedwood which was a lot of fun.
Willie

 

[Kens 50 PU]

Nate won't steer you wrong!

That is one good looking truck! Feel free to post more pics, as we never get tired of looking at vintage tin!

As far as Nate's advise, he's like Ivory soap, he's 99 and 44/100% right! Us AD boys hang on his every word! Glad his advise worked out for you!

 

[willie1957]

Thanks Ken. I'll be sure to post some more pics in the future.

 

[vwnate1]

Sweet !

That's a BEAUTIFUL truck right there ! .

Good on ya for going back to basics with the old Babbit Pounding 235 C.I CAST IRON WONDER .

I'm glad my advice helped out , as you prolly figgered out by now , I'm an Accountant in DeMoines who's never seen any actual old trucks or tools , I drive Kia or ride the bus mostly......

 

[vwnate1]

Obtw :

Now it is time to put in a Pertronix Ignitor and buy a timing light and set it up for some REAL BOWTIE POWER ! .

 

[willie1957]

Thanks for the kind words Nate and thanks again for the help.

As far as the Pertronix ignition, it sounds like a great idea. I'll definately consider it when the budget will allow.

Oh and "Accountant in DeMoines", yea right! I was thinking more like a Bull Rider from Montana!

 

[vwnate1]

Could Be.......

An old Farm Mechanic from New England .

Don't forget to re-adjust those valves as they will bed in and close up again , once you've done it a few times they'll normalize and only need adjustment once a year or 10,000 miles .

If the $100 Pertronix is too high , keep an eye out for a Timing Light and dwell Tachometer , they're all over the place in yard & tag sales plus swap meets , thrift stores and pawn shops .

Once you have them ask and I'll walk you through the Tune Up regimine and help you unlock the hidden horsepower in your Stove Bolt engine .

 

[willie1957]

Nate, I have read your post where you tell about timing the 235 with the adjustable timing light. That sounds great but aren't you essentially just advancing the timing and couldn't I accomplish the same thing with an ordinary timing light or is it that there wouldn't be any marks to time it to?

I believe that besides the "BB" and the "Chevron", there are a couple of other marks on there as well. What can you tell me about those?

Right now I have the dwell set at 32 degrees and the timing set with the BB lined up dead nuts on with the pointer and of course with the vacuum hose disconnected. And as I told in my initial post, it's running pretty dang good!

Willie

 

[vwnate1]

Ignition Timing

AFIK;

There should only be two marks stamped into the flywheel : the Chevron or triangle (always one or 't other , never both) and these are the TDC (OT for our German friends) marks , useful in setting up the initial build , valve timing checks and , my favorite , setting the full advance timing .

If you're using the BB (7° BTDC IIRC) @ idle speed of 600 RPM or less and it runs out well , leave well enough alone .

FWIW , if the carby is correct , there should be no vacuum signal @ idle so it's not necessary to disconnect it , once you've investigated and ascertained this.

All - in ignition timing is best as it sets the timing where the engine is working and compensates for wear , mixed parts and so on .

If it runs well , don't fool with it .

G' night ! .