VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 spark plug inserts

hello
Has anyone experience of using inserts so that modern spark plugs can be used in a four cylinder Chev?
If so, which plugs work well?
Thanks

I have a set of inserts for my 28. I ran them for years with Champion 89YC6 plugs with no problems. Fairly common. The inserts usually have a flat seat and many modern plugs have a tapered seat so watch that. Ultimately I was told that Autolite 3077, an original type of plug was the best thing. It wasn't the best thing for me. I had major problems and pulled back to Autolite 3076 which is fine.
The advantage of inserts is that you can buy an appropriate modern plug which is new. I found that many original type plugs available were old stock that were unsold because they were not appropriate. Hope this helps.

I had 87S plugs in my '25 when I first got it. I tried the 3077 and had very bad results. So I hunted around and found the original AC plugs. No markings on the plugs, just the letter 'B' on the box. The car ran great.

I have a mildly-modified 28 motor and use the inserts with long-reach Bosch Iridium 4514 plugs. Runs great and no pre-ignition like I had with Autolite 3077.

This thread just proves that everyone has their favourite plugs with a story why the others don't work.

I have now converted 3 1928 Chevs to 3077's with no problem, providing the timing is spot on.

All 3 now have improved response and power. I run the plugs at 30 thou and points at 23 thou.

Previously I ran w14's, they sooted up and engine ran sluggish.

To protect the valves when running a hotter plug and also as an Upper Cyl lubricant I run 1 litre of diesel per tank of gas and have done so since 1999.

Anyway that's my story, putting in a good word for 3077's. I believe the same result can be achieved with Champion W89D, but they are more expensive.

Cheers

I run Autolite 3077 or Champion W89D plugs in my three '28 Chevys. Never had a problem with either of them. Generally get approx. 18 mpg at moderate speeds. The Autolite 3076 tend to soot up.

Thanks for all this useful information
Steve

Hi Chipper

I agree with the 3076's sooting up, and the same with Champion W14's

Cheers

Ray

Just to add some info, the inserts referred to by coachman28, are the same as Ford Model A plug adapters, and available from the numerous Model A vendors.

http://www.snydersantiqueauto.com/spark-plug-adapters

I had been using the infamous 3077s, and while they performed better than stock, I went the route of inserts and the Bosch iridium plugs, 4514s, and haven't looked back. One thing, though, was what to do with all those obsolete 3077s....so, I sort of cut em up, drilled and tapped them, to make my own inserts, came out really well. Anyone else want to send me their 3077s to cut up, well, I would be quite pleased.

Ciao,

Jay

No Thanks Jay,

will keep my 8 sets of 3077's and after that Champion W89D's which are the equivalent.

How are you Jay, no doubt you were expecting me to bite?

Cheers

Ray

I'm not going to bite either. You can cut up and modify the lesser performing (and often less cost) plugs to get the same result. Or buying the already available adapters.