Tec H50 with Oval Bore Mikuni problem ... pics and Videos ...

Found a break in the action to get the H70 valves fitted to the H50.
They had already been lapped, just needed to grind the gap.



The exhaust came out at .010 and the intake was .011 when I was done.

Interesting note ... I demaged the intake valve out of habit ...
When I tried demaging the exhaust I found it was non-magnetic.
Maybe its stainless?

Were getting there!
 
Found a break in the action to get the H70 valves fitted to the H50.
They had already been lapped, just needed to grind the gap.



The exhaust came out at .010 and the intake was .011 when I was done.

Interesting note ... I demaged the intake valve out of habit ...
When I tried demaging the exhaust I found it was non-magnetic.
Maybe its stainless?

Were getting there!
I'm watching Kevin!!
I also am still looking for a source for those K suffix lifters.. I put some feelers out...If I get a good reply I'll let ya know...
 
Put her back together, new head gasket, retainers and keepers on the valves, checked the gap again with the springs installed, A-OK.
I had one new plug so I saved it to get a reading.
Fired her up with an older plug, took quite a few pulls to get her going, 10 or so, I used starting fluid to coax her along.
Wondred if I clocked the cam wrong, then VAROOM!
Off the bat she sounded better, idling at 1800 RPM, I adjusted the Mikuni to 800 RPM and tweaked the carb while letting the motor warm up.
I brought the Rs up but never went over 5100 .... she sounded nice ... there is a SLIGHT miss that at this point I'm gonna say is carb jetting or running with no load.
It was not spitting ANY gas out the back of the carb.

I am 100% sure it was bent valves "maybe just the intake (?)" and I had made the problem worse when I repeatedly tried to reach 7000 RPM.
I am also convinced the valves that came in that motor while correct for the motor are not capable of 7000 RPM.

I put in a new plug, brought it to 4500/5000 RPM and held it there for 2 mins or so ...
The plug looks just a tick rich with a 125 main jet. Should I go smaller?


I want to personally thank every one listed below here (and any I missed!) for sticking it out and getting to the bottom of this.
I cant speak for everyone but this was real learning experience for me.

Thanks!!

[MENTION=53489]Studeman68[/MENTION]
[MENTION=3072]ole4[/MENTION]
[MENTION=53722]FOMOGO[/MENTION]
[MENTION=55208]danford1[/MENTION]
[MENTION=47323]OND[/MENTION]
[MENTION=28798]the beekeeper[/MENTION]
[MENTION=31879]CarPlayLB[/MENTION]
[MENTION=339]delray[/MENTION]
[MENTION=31239]Havasu Dave[/MENTION]
[MENTION=26262]David wulf[/MENTION]
[MENTION=56629]jaimenv[/MENTION]
[MENTION=21845]creia[/MENTION]
[MENTION=27186]fistfullabar[/MENTION]
[MENTION=53707]Davis[/MENTION]
 
I would say drop the main a bit, should have a nice light tan color............Kool on getting it running again, how ya comming on the belt drive setup?...........We need to get this beast out again!............Tom.
 
how ya comming on the belt drive setup?...........We need to get this beast out again!............Tom.
Everything in the TAV is done enough to motivate her along ... I just need the belt. It's been ordered and it should be here Monday.

I will goof around with her this weekend and get her road ready .. put the belt on and try it!
 
The plug look acceptable to me for running under no load. The only true way to read the plug is under full load with a clean shut down at max RPM's. I think it will be fine with what it looks like now.

Doug
 
The plug look acceptable to me for running under no load. The only true way to read the plug is under full load with a clean shut down at max RPM's. I think it will be fine with what it looks like now.

Doug
X2 Kevin.. I think Doug is probably correct in his thinking.. more load will generate more heat, and that would make me think more thorough combustion and higher cylinder pressures.. I think of it like this.. My 68 Galaxie runs great but gets operated at little load most of the time.. I can always tell when I need to "clean" her out.. I get it warmed up, then go lay into it hard and watch the carbon cloud behind me...I'll bet that plug cleans up about right after a good ride. I'm curious to see how she runs under load.. I may just bolt mine together as is and go have fun for a while till I find the pieces to do the lighter valves,,,
 
You might try VKE Motorsports in Colorado for the lifters you need.
http://www.vkemotorsports.com/catalog/2010_VKE_web_catalog.pdf
Actually, the Chicken has both the long, and intermediate lengths of lifters. He only had 6 of the longs, but had 50 of the other. I bought all the longs he had, and 6 of the intermediate ones. [MENTION=44698]Sixpac440[/MENTION], PM me your address and I'll send you a set of each when they hit my doorstep...They were only $2 each and he is throwing them in the box with the coil I bought so no shipping on them...:thumbsup:
 
Actually, the Chicken has both the long, and intermediate lengths of lifters. He only had 6 of the longs, but had 50 of the other. I bought all the longs he had, and 6 of the intermediate ones. [MENTION=44698]Sixpac440[/MENTION], PM me your address and I'll send you a set of each when they hit my doorstep...They were only $2 each and he is throwing them in the box with the coil I bought so no shipping on them...:thumbsup:
Heck yeah! PM sent!! BOOYAHHH!!
 
Well Kevin I pondered your advice on cutting the valve seats with a 30 degree stone a great deal last night and I thought well I'll at least try it on a junk block I have so I can get the thought of it out of my brain.... well....it went pretty darned well so I brought out my good HM80 block that I'm going to build this winter and gave it a go. I was pleased with the results even though the stone took back some of the eye brow.. probably makes a little more clearance for air flow.. So I got the H50 out, crossed my fingers, and gave it a whirl too... seems like it turned out pretty good too. The pics below are after I lapped them for only a quick moment to make sure I had a concentric pattern.. and it looks like I do...I will do more lapping when assembly time comes on each....tell me what ya think....

HM80;
IMG_2498.JPG

H50;
IMG_2501.JPG
 

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That looks pretty good Steve!
The Litmus test will be when runs but it looks pretty even.
It just needs to make a good seal.
Here is a pic of [MENTION=3072]ole4[/MENTION] s motor where a lot of metal was removed, hitting the eyebrow shouldn't be a problem.

I believe he said it would lower compression but it made up for it on the higher RPMs.
 
Thanks Kevin, I have no doubts it will seal up. I'm gonna do some more lapping with a finer compound at assembly. Also, It looks like the intermediate length lifters (ones in the little boxes) will be the way to go.. and we'll definitely need to tip the exhaust valve to get the correct gap on it. The intake is pretty good and coming in at around .011-.012. @Sixkpac
 
Well Kevin I pondered your advice on cutting the valve seats with a 30 degree stone a great deal last night and I thought well I'll at least try it on a junk block I have so I can get the thought of it out of my brain.... well....it went pretty darned well so I brought out my good HM80 block that I'm going to build this winter and gave it a go. I was pleased with the results even though the stone took back some of the eye brow.. probably makes a little more clearance for air flow.. So I got the H50 out, crossed my fingers, and gave it a whirl too... seems like it turned out pretty good too. The pics below are after I lapped them for only a quick moment to make sure I had a concentric pattern.. and it looks like I do...I will do more lapping when assembly time comes on each....tell me what ya think....

HM80;
View attachment 98664

H50;
View attachment 98667
They look good with the exception of width. They are pretty wide on the contact area.

Now wide isn't bad but not so wide would be better for flow. A 3 angle cut would clean them up real nice.

Doug
 
Well Kevin I pondered your advice on cutting the valve seats with a 30 degree stone a great deal last night and I thought well I'll at least try it on a junk block I have so I can get the thought of it out of my brain.... well....it went pretty darned well so I brought out my good HM80 block that I'm going to build this winter and gave it a go. I was pleased with the results even though the stone took back some of the eye brow.. probably makes a little more clearance for air flow.. So I got the H50 out, crossed my fingers, and gave it a whirl too... seems like it turned out pretty good too. The pics below are after I lapped them for only a quick moment to make sure I had a concentric pattern.. and it looks like I do...I will do more lapping when assembly time comes on each....tell me what ya think....

HM80;
View attachment 98664

H50;
View attachment 98667
I had to track down the pics on the laptop but these seats were cut with the kwik-way cutters pictured. 3 angles just for a reference to seat width. This head is a Predator Hemi head done by Sneaks, Gary Costanza for the Savage that Eric, OND built for me.... To many projects...





Doug
 
They look good with the exception of width. They are pretty wide on the contact area.

Now wide isn't bad but not so wide would be better for flow. A 3 angle cut would clean them up real nice.

Doug
Yeah I agree with you Doug for sure.. and that isn't out of the question at this point, but the tools needed to do that are really expensive, and I don't know if I want to trust two more angles to some stones.. I got real lucky here with the 30 degree stone but I'm worried that pushing my luck won't end well... seems to be common thing for me on this type of stuff..I'm gonna ponder it though...:smile:
 
Yeah I agree with you Doug for sure.. and that isn't out of the question at this point, but the tools needed to do that are really expensive, and I don't know if I want to trust two more angles to some stones.. I got real lucky here with the 30 degree stone but I'm worried that pushing my luck won't end well... seems to be common thing for me on this type of stuff..I'm gonna ponder it though...:smile:
Stones were the way of the world for a long long time. I wouldn't hesitate to cut multi angles with a stone as long as I had a good tool to dress the stone and a good pilot to run the arbor on. I have seen big horsepower made with heads ground with stones and the valves done exactly the same way on a stone. I don't see anything to be hesitant about if you have good equipment.

I don't have access to the equipment anymore and instead of trying to track down somebody local I just sent a head to Sneaks. Quick and simple on these little OHV motors.

Don't be Skeered.... Jump on it. :hammer:

Doug
 
Tell ya what, being a Die maker I thought stones were not a good idea and I told Steve as much in a PM ... but after reading the above I went on eBay and typed in "valve seat grinding stones" and damned if 180 results didn't pop up!

Like I told Steve I ordered this for $20 delivered ... BIG DEAL CARBIDE TIPPED VALVE SEAT CUTTERS 38MM,30DEGREE, WORKING FOR GARAGE | eBay

I will not be doing lots of seats, just one so it will work for me.
But stones look like a fine way to do tis as well!
 
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