j par
Well-hung Member
^^^I just noticed the heat ring on the colder one...
My home inspection of Speedmaster heads
- Thread starter 318willrun
- Start date
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Jpar, you seem to have a sense of entitlement. Do you think they owe you this information? They are posting their results to us for free and you are complaining. There is plenty of head porting info on the net if you look for it. With pictures too. https://www.hotrod.com/articles/mopp-0001-360-engine-head-porting/ https://www.hotrod.com/articles/mopp-0210-porting-383-440-aluminum-replacement-heads/ https://www.hotrod.com/articles/cylinder-heads-ii/
j par
Well-hung Member
You're wrong I have no entitlement issues...
I've read it twice and learn nothing... Except for they seem to know what they're doing...
Well I shouldn't say nothing, but nothing about porting that's for sure..
I learned exactly what was told right here on this thread..
"Home inspection of Speedmaster heads"
Buying these on sale loaded is a good budget way to go for a small bump in performance over your stock heads..
By the time you loaded these up with expensive parts and had expensive work done to them you'd be at least at getting some promaxx shockers or well on your way to some trick flows...
now I'll say it for the hundred and tenth time I enjoyed reading what they did and I'm glad for them that they can do it but as far as helping me the only thing I learned was I did great by buying what I bought for what I expected..
I'll follow the tips on this thread and try to follow them..
I will follow 318willrun's way of going with these heads...
What you should have done was took one of them dirt spark plugs and screwed it into you nice new head and took a picture.
instead of just showed us you different heat range spark plugs. The threads are the same length on both, screw one in and take a picture.
instead of just showed us you different heat range spark plugs. The threads are the same length on both, screw one in and take a picture.
j par
Well-hung Member
I took what 12many said as the truth when he said that the spark plugs didn't cover those threads.. so I looked at the spark plugs he used and compared it to the new spark plugs that I now use..
and kind of like you said I don't want to screw in old oily spark plug into my new heads... See how nice I answered...
The question was the sharp thread poking out and if the spark plug screwed up that far.
The heat range had nothing to do with the sharp spark plug threads.
And, is why i suggested you put a spark plug in, because you have one in you hand, and you have the head and thread in question.
The heat range had nothing to do with the sharp spark plug threads.
And, is why i suggested you put a spark plug in, because you have one in you hand, and you have the head and thread in question.
I knew you meant the intake and yes, the burr was all the way around
too cold a plug in my opinion.... loss of power in my opinion too.... but just my opinoin
probably had to have the seat or valve ground a little extra on that one is all. I won't worry about the .010, its really not that big a deal.
j par
Well-hung Member
I'm creeping my way up onto hotter plugs. It's just what the recommendation of the machine shop that did some of the original work on my motor gave.. I was having problems with run on due to the higher compression of my motor.. ultimately I found out I just need more octane... As you know I've been getting it more street friendly so I can enjoy it more and get more familiar with it to diagnose...
j par
Well-hung Member
And back to answer I'm posed to 480...
I compared the two spark plugs to see there thread depth.. and just added a small bit of conversation about the heat range... Since the thread depth were not any different there wasn't any reason to doubt what 12many said...
The plug type used are the same for the SM’s and the TF’s. I don’t have a pic of a plug installed in the SM’s but here’s what I’m talking about. Radiused, no sharp edges and the plug electrode more exposed. Install a plug and see how the electrode is recessed and the amount of sharp threads are exposed.
I would think sharp edges could cause detonation.
And it’s in a TF head at that. I raised both eyebrows when I checked the SM’s with a plug, but just on looks alone yeah....hmmm! Maybe someone can run a plug in and post a pic to show this on the SM? Here’s an interesting link:https://www.hotrod.com/articles/hrdp-1005-spark-plug-reach-tech/
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I’ll try to screw a 3911 in mine today. I would run down there now before I leave but it’s on my flowbench
I think I read on SM site. Standard 340 plugs are recommended?
Looks like no consideration was made for how the plug is presented? to the chamber. Put the hole here, cut the threads, done! I see you cut back the electrodes even further than they come on the Autolite racing versions? Or just camera angle?
What if anything can be done with the plug hole? Kim
I agree. I know I’m going to take a better look at things. Thanks for bringing it to our attention
Machine the plug seat deeper so the plug is closer to the chamber?
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