Not very DIY

[chancer]

What cause a Valve to drop? cheap or old retainers?

 

[Flyinhillbilly]

Probably. These were the same valves and retainers that were on my what would it take? Motor and every one since. I'm sure they probably just wore out. It probably didn't help that I was ripping on it without the first care about whether it stayed together or not. It was screaming harder than it has before, and I've seen 6800 with it on the old setup, so my guess is that it was north of 7k. I guess that means the air conditioner oil is ok as I rode it quite a bit and without mercy. On the neighbors track I could run wide open except for one corner, with this motor I could only hammer it on the straights, and it would still spin some. I think it's going to be a beast when I get it back together.

 

[Flyinhillbilly]

I just remembered that my neighbor had the head from the free GX 160 that I got from the rental store stashed. It's 18cc rather than 14cc, but it will get me back in business while I round up a big valve head. Also ordering a set of dual valve springs and automotive style retainers for it. I'll go ahead and upgrade the rod and cam while I'm in there so that I should be able to flatfoot it.

 

[Whitetrashrocker]

How much can you mill off the head. I got .030 off my Briggs easily. Maybe could have gone a few more if I clayed it.
Get that compression back up there bud!

 

[Flyinhillbilly]

I've pretty well got my heart set on a big valve 14cc. I have to put a transmission in my black truck, so that's draining the fun account ATM, but soon I will own one. I'm just going to port this one like I did the 14cc I had on it and see what it runs like until then.

 

[Whitetrashrocker]

Ahh tranny problems.
Do you rebuild yourself? It's gotten expensive lately...

 

[Flyinhillbilly]

I usually do, but I have enough going on ATM that I'm going to farm it out to the guy that built this one. It came out of a turbo drag car that I used to drive for a friend, so it's a pretty sweet unit. It has sat since 08 and now won't go into 3rd so I think it's just something stuck in the valve body.

On another note I started on the 18cc Honda head. I have a couple of guys getting me prices and a program together on the big valve head, but I'm going to go ahead with this one just to see if I can do a decent job. I've got the port shape pretty well figured out I think as my 14cc would straight rip before it dropped a valve. I found the valves worn out in this one so I'm going to open the seats up and go to 27/25mm stainless valves.

 

[Flyinhillbilly]

26mm max on the exhaust seat.

 

[Flyinhillbilly]

Made a tool to press out the valve guides as I thought it would make the porting easier (it did by miles)

 

[Flyinhillbilly]

It even fit the first try

 

[Flyinhillbilly]

Then I pressed out the guides and ported the runners. Next I un shrouded the valve seats and softened some edges in the combustion chamber.

 

[Flyinhillbilly]

Then I took the old guides and streamlined them on the valve end. I was just figuring out how I wanted to do it before I went to carving on new guides. This made a big difference on my other head and I just did it with a dremel on that one.

Stock

 

[Flyinhillbilly]

Modified

 

[Randy H]

FHB
Do you shorten the guide? I guess it could cause problems. Some engine though, there's no guide our even guide boss in the port.

 

[Whitetrashrocker]

Nice.

 

[Flyinhillbilly]

I worked the boss where the guide comes through pretty good, raised the roof a touch, and worked over the short turns pretty good. I'm tapering the guides from where they come out into the port roof to the valve without shortening them to hopefully maintain valve stability at high rpm and help the air transition onto the valve at the same time.

Intake

 

[chancer]

Ok your Title no longer Fits your thread.

Nice work though.

 

[Flyinhillbilly]

Exhaust

 

[tinamcjittles]

Exhaust

She's gonna breathe so well

 

[Flyinhillbilly]

Bought some tires and wheels