If you go to page two about 3/4 way down the page it shows the sparkplug in the head.

Also of note here, I don't think ANY of us are getting correct static compression readings with our compression testers.
The reason I say that is because the threaded end on a compression tester is NOT as long as the threaded end on a sparkplug.
This means your actually adding some cc's to your combustion chamber because it don't thread down all the way.
Just my opinion.

My question was meant to be, is the plug extending the same on the new head as it is on a stock head? As far as the gauge not being as long as the plug, is it possible it's shorter to compensate for the plug not being flush, like the end of the gauge is?

Yes

Pics of the semi finished head

Just finished the pressure test.
OH GOD this is bad right now LOL.
This is what I was worried about and commented on earlier in this post.
I only got two small pin holes in the weld on the cap (very easy fix) but the entire base is leaking all the way around. I welded this on the inside on purpose because I needed the outside clean and clear of weld for the head nuts.
Looks like I will be force to weld it on the outside.
Die grinder/re-weld, die grinder/re-weld, die grinder/re-weld until I get it right LOL.

Bummer, but very cool progress!

It's difficult to get an air tight weld, on the first pass, on aluminum, with a mig. Preheated and tig would probably better the odds. The welds could be made a lot smaller that way too.

I don’t see any leaks.
Keep at it CO.

What if you were to use a bolt with copper spaces, like a thick washer in each hole so the weld would not affect the bolt head area. Am I making any sense?

I would love to own a tig machine but there is no way in hell I am going to pay that kind of money.
I don't own a plasma cutter for this reason as well.



Yeah you are making sense.
But the problem is not the bolt hole itself, it is the clearance needed for the bolt head.
Any welding on the outside severely cramps this clearance issue. Two of these bolt heads actually just touch the outer ring right now but there is clearance to turn them. Any welding screws this.
I guess I should clarify this a bit better. When I say bolt head I actually mean nut because I am using the Honda studs on the head.
It's Christmas time so this will be on hold for a while before I get on it again.

Picking away at it.
Had to make some custom washers because after the welding was done, there was no way the nuts would clear.
Now I have run into another issue. I forgot to drill/tap a hole for the temp sensor in the head. FFFF. Now I have to pull the head again ----------- for about the 100th time.

Are you going to weld those spacers in place? You will almost have to, so you get proper torque.

It's tough to weld steel to aluminum -- .
Nah good enough.
Besides I am running an O-ring so once it reaches crush you don't need more. Even though it will be a point force, it will still be a force on the plate. I will slightly over torque it a bit and have thought about it. Also when ever I torque down one of the heads on my machines, I also use the blue non permanent Loctite because on all the other heads the bolts are inside the water jacket. You can't get at them unless you drain the system.

Ok - why not just make them from aluminum and weld? Oh hell don't answer - you know what you are doing.

I thought about that after you mentioned it but I don't have any aluminum round stock that small around here at the moment. But most important is that I am afraid to weld on this head again. I had a hell of a time sealing the leaks and if I weld on some aluminum spacers I might end up with a leak somewhere in behind one of these spacers. I know what you are after but unless you were standing in my shop last night watching, it wouldn't do justice to the leaks issue.
I have to work with what I got and hope it all works out.
I do give consideration to comments made by people because NOBODY has the lock on good ideas. I'm like that at work too.

My first thought is you are not getting a full even contact patch under the spacer since it's angled. I went through a similar issue when I built my exhaust manifold. Looks awesome.

Could you not grind down the weld so that the nut fits better? And i would suggest an allen nut (like this) in replace of the head nuts

An allen nut is skinnier and would give you more clearance because you do not have to fit a wrech on it.
Just a suggestion although it seems like you have it figured out.
Awesome work and awesome build!

No I can't. If I do that I will have leaks again. Guaranteed.

Beer poacher gave me a good idea a while back. He didn't like the mickey mouse pull cord handle. He told me to go the lawnmower shop in town. They got a whole pile of wrecked lawn mowers outside. I could get a rubber handle for free -- . Price is right. Think I will do that.

I've made spacers exactly like that in the past. The only problem I had was the studs bent when I torqued them down, this made it difficult to get it apart when needed. It was on a home made brake.

It seems I may be missing something because several of you don't like this idea. So re-examining this issue I think I will file down these spacers so that they hit the weld area and the base plate at the back of this spacer. Some of these spacers actually do that right now. Looking at the one photo posted, it looks like I can get away with one or two non angle cut spacers as well. Going out to the shop now to work on this project.

I aint knocking it. My studs were smaller than what you're using, and I cranked them down probably tighter than what you need to do.

Oh ok that makes sense I wasn’t getting it at first. That is a good fix though

Ok -- Engine is together now.
Will pressure test this Engine tomorrow when the silicone and blue Loctite is dry.
I put a ring of red silicone next to the O-ring in case the O-ring fails. Probably wouldn't help but it is worth a try. Put blue Loctite on the head nuts.
Numbered all custom made spacers so that they get put in the correct spot.
Replaced the homemade "T" handle on the pull start.
If this thing passes the pressure test I will start the installation. When complete will fire it up in the driveway and heat cycle it. No riding around here this time of the year as there is snow in the hills and it is raining like hell here the last few days. Today was nice -- the sun came out for 2 hrs, then fell behind a hill.

I don't think I would have the patience to let the rain and snow stop me from testing it..lol