Author Topic: Valve stem to guide clearance question (Read 13884 times)

MRieck · « **Reply #25 on:** July 05, 2007, 10:01:09 PM »

Quote from: Hockers Choppers on July 05, 2007, 08:58:12 AM

mic'd measurement, not with the dial indicater like the manual shows. The intake ports were soaked with oil! has to be coming from the guides.

Jesse
What are your cam lifts and are you banging the retainers off the seals OR pulling the keeper cut out deep into the seal?

Hockers Choppers · « **Reply #26 on:** July 06, 2007, 06:38:27 AM »

new seals. The cam is a 63a webcam, not sure on the lift, but its nothing ratical. VERY good point though, I'll have to look into that. Thanks,

crazypj · « **Reply #27 on:** July 06, 2007, 08:42:55 AM »

Quote from: Hockers Choppers on June 11, 2007, 04:34:00 PM

I guess .001 is still too much clearance?? intake ports are wet with oil!!

If its got oil above the guide towards carbs its coming from somewhere else. Check engine breather isn't trapped anywhere.
Could someone post a picture of a pin gauge please as I don know what it it. Using drills or other solid bar for measurement wont ell you if guide is oval. I prefer ball gauges as they will measure (or at least indicate) ovality. Problem is, they are really difficult to use correctly and depend on feel. I always teach people to use them left handed, that way you can get same feel taking measurement with mic as you had in the hole. (rotating slightly will allow out of round to be felt.) With practice its relatively easy to feel 0.0001"~0.0002" differences
PJ

Hockers Choppers · « **Reply #28 on:** July 06, 2007, 04:04:09 PM »

Running CR 29's with K&N pods. Have a K&N style breather on the valve cover. Has to be from guides?

Big Jay · « **Reply #29 on:** July 07, 2007, 04:23:27 PM »

If the guides are loose in the head, oil can come down the outside of the guide. The problem is more severe when there is a lot of intake vacuum.

Jay

Hockers Choppers · « **Reply #30 on:** July 07, 2007, 04:30:20 PM »

guides are tight and used red lock tight on them. 63a cam has a .370 lift. not too ratical by any means.

SOHC steve · « **Reply #31 on:** July 07, 2007, 05:03:00 PM »

Like Jay said..loose guides,scored guide holes in the head? I never done any bike guides before,but have done countless aircraft engine (aircooled) guides,I read you used "red" loctite? I really doubt any loctite should be relied on to retain a guide in the head,if it is loose,ream out the bore and fit and oversize guide.did you port the head while it was off? If so,you didnt go too far and get into some porosity? How about oil return? there isnt something screwy with maybe the wrong head blocking off oil return and flooding the guide areas? Hope this helps,hang in there and good luck sorting it out

Steve

Hockers Choppers · « **Reply #32 on:** July 15, 2007, 11:11:15 AM »

Is it possable that the oil is blowing up inside the intake valves from the cylinder? I only had 30 miles on the engine, would the rings have been seated? Ken at cyclex said the guides/valves looked OK. He's been doing this for 30 years. Must be from rings? I'm almost out of hair and liver. I think the 63a webcam I have opens at 27degrees btdc. so it is possable. I guess?

Wheelhorse77 · « **Reply #33 on:** July 20, 2007, 09:15:28 AM »

Quote from: Hockers Choppers on July 15, 2007, 11:11:15 AM

Is it possable that the oil is blowing up inside the intake valves from the cylinder? I only had 30 miles on the engine, would the rings have been seated? Ken at cyclex said the guides/valves looked OK. He's been doing this for 30 years. Must be from rings? I'm almost out of hair and liver. I think the 63a webcam I have opens at 27degrees btdc. so it is possable. I guess?

Ok, so you rebuilt the lower half as well? Did you do it or did someone else assy the short block? Did they space the ring gaps 120 degrees apart on the piston. Is it a three piece oil control ring set up? Did they do the proper 25 Degree crosshatch? Did they gap the rings correctly?

New rebuilds will consume some oil for a short time, but never to the point where oil is blowing out of the pipes or heavily smoking. You will notice between changes that you are a tad low, but once the rings fully seat, you are good to rock and roll.

Hockers Choppers · « **Reply #34 on:** July 22, 2007, 06:27:36 PM »

All that was right, but the one piece oil rings were not seated all the way yet! they had a few black spots on the faces. BUT, would the oil be getting up in the intake from that?

Wheelhorse77 · « **Reply #35 on:** July 23, 2007, 06:43:37 AM »

Is it all four tracts that are getting oil in them?

Hockers Choppers · « **Reply #36 on:** July 24, 2007, 05:49:24 AM »

Yes, all 4 had the same amount of oil, and all 4 oil rings had some unshiney spots on the face.

crazypj · « **Reply #37 on:** July 24, 2007, 06:25:11 AM »

Did you oil cylinders before re-fitting and do you have a stock cam?
Oiling cylinder walls prevents rings seating and even a mild or stock cam will allow some blow back at low rpm.
Probably a good idea to put it back together and give rings a chance to seat properly.
Personally I assemble dry except for some oil on lower edge of piston skirt (front and back only, the side don't need it)
Small end gets lubed but definitely not the rings.
PJ

Wheelhorse77 · « **Reply #38 on:** July 24, 2007, 07:24:15 AM »

I've never not oiled the rings and all of mine are set in per OEM specifications and per ASE engine rebuilding practices. You always lube the cylinders because rust can set in over night and really prevent a proper sealing of the rings. You should not break an engine in using synthetic is the rule of thumb.

The rings theoretically should be worn equally all the way around if your bore is true. A circular ring doesn't seal in an egg shaped bore.

Hockers Choppers · « **Reply #39 on:** July 24, 2007, 02:28:07 PM »

assm. dry, webcam 63a, cyclex big bore kit with one piece oil ring, honda oil ( not synth ) , only ran 30 miles. But saw smoke and had oil up in the intake so I assumed it was guides. Sent head to Ken and he said head was fine. Must be rings? Where in the Hell else could it be coming from!!!! I'm out of ideas. I wish I would have ran it more before I tore it apart.

MRieck · « **Reply #40 on:** July 24, 2007, 03:55:02 PM »

You could have cut the guide seals installing the valves. The retainers could be hitting the seals too....I have seen this with a .375 lift intake that had a valve job that left to little stem height. A 1 piece oil ring is not good to begin with and if the bores aren't perfectly round you will have trouble. I'd do a leak down just to start with. Not a compression check.....a leak down.

SOHC steve · « **Reply #41 on:** July 24, 2007, 04:17:12 PM »

Do these guides have a collar on them so they stop in the correct position when they are fitted?If they dont,they must be measured so the correct height is obtained,if they are left too high the top spring retainer could possibly strike either the guide and/or the top of the guide.

Hockers Choppers · « **Reply #42 on:** July 24, 2007, 04:48:43 PM »

Hey Mike, Measured the valve from the edge of the cut away for the retainer to the top of the seal, (.375 ) I think my cam is a .370 so I should be good there. Only smokes at 5000rpms and up. Valve job should give more clearence.

Steve, they are APE guides, I'm sure they are right. New heavy springs.

MRieck · « **Reply #43 on:** July 24, 2007, 05:04:03 PM »

Quote from: Hockers Choppers on July 24, 2007, 04:48:43 PM

Hey Mike, Measured the valve from the edge of the cut away for the retainer to the top of the seal, (.375 ) I think my cam is a .370 so I should be good there. Only smokes at 5000rpms and up. Valve job should give more clearance.

Steve, they are APE guides, I'm sure they are right. New heavy springs.

Jesse......005 isn't much seal to retainer clearance. This really rings true with the 5,000RPM part. A valve job CAN give more clearance but it really depends on where you seat the valve. I move the contact area between the seat and valve as far as possible to the outside to increase the seat area.....you decrease stem height. If you install oversize valves everything is new in regard to stem height etc. APE guides do not sit as low as Kibblewhite. Kibblewhite also have separate part #'s for intake/exhaust guides. If you use APE Ti retainers with the guides you get some clearance. I'm sure you have the retainers banging off the guide seals judging by your descriptions.
Mike

Hockers Choppers · « **Reply #44 on:** July 24, 2007, 06:55:10 PM »

Mike, I'm talking .375 from the top of the seal to the edge of the cutaway for the retainer, not to the bottom of the retainer. Do you think I'm getting some valve float right at that rpm? I seem to have a dead spot from 5000-7000 rpm. runs good over that.

Hockers Choppers · « **Reply #45 on:** July 25, 2007, 10:58:15 AM »

mocked up the valve train this morning. The vavles are being pushed down in the seal too far! The after market seals are too tall? I put an old stock seal on the guide and it looks OK. I have a set of Honda seals on the way!

Wheelhorse77 · « **Reply #46 on:** July 25, 2007, 11:34:53 AM »

Quote from: Hockers Choppers on July 25, 2007, 10:58:15 AM

mocked up the valve train this morning. The vavles are being pushed down in the seal too far! The after market seals are too tall? I put an old stock seal on the guide and it looks OK. I have a set of Honda seals on the way!

Good deal, let us know how she turns out.

MRieck · « **Reply #47 on:** July 25, 2007, 01:47:59 PM »

Quote from: Hockers Choppers on July 25, 2007, 10:58:15 AM

mocked up the valve train this morning. The vavles are being pushed down in the seal too far! The after market seals are too tall? I put an old stock seal on the guide and it looks OK. I have a set of Honda seals on the way!

Hmmm....I thought so.

MRieck · « **Reply #48 on:** July 25, 2007, 06:42:12 PM »

Quote from: Hockers Choppers on July 25, 2007, 10:58:15 AM

mocked up the valve train this morning. The vavles are being pushed down in the seal too far! The after market seals are too tall? I put an old stock seal on the guide and it looks OK. I have a set of Honda seals on the way!

You need at least .020 retainer to seal.

Hockers Choppers · « **Reply #49 on:** July 26, 2007, 02:07:24 PM »

I have plenty of retainer clearance. The seals are .150 from the top of the guide to the top of the seal. The stock honda one I took off are .110. With the after market seals I have .330 from the top of the seal to the edge of the stem where it begins to tapper off. The cam has .350 lift at the retainer, so its pushing the valve .020 into the seal!! With the stock seals I should have .020 to spare. I can't believe nobody else has ran into this problem. The 63a webcam is supposed to have .370 lift. it only has .350 thank God I'de have a bigger problem if it did!! Damn hotrods!!! Anyone else running a high lift cam?

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Author Topic: Valve stem to guide clearance question (Read 13884 times)

SOHC steve

SOHC steve