Grinding down the base circle of a cam is a traditional tuning technique, it increases valve lift and gives longer opening. The key is to make a smooth transition from the new base circle to the lift segment and have a progressive lift. People complaining about loss of cam hardness forget that the base circle is not under load, so not subject to wear. Note the very large oil feed holes in the base of the cam - it's not likely that this cam is starved of oil.
@@raywallace1104it not that hard pal in Nam we did it since 2000s, it kinda easy but the cam not alway good , sometime it have a cam that you can’t use that why no body do this since 2015
Да, метод рабочий, уменьшая базу кулачков можно увеличить подъём клапана и фазу. Но есть много "но". Во-первых точность оставляет желать лучшего, особенно выравнивание вручную. А во-вторых такой распредвал без термообработки получится одноразовым, на один заезд
@@ДмитрийАфанасьев-ь9ч посмотри как работает распредвал и с какой части кулачка начинается давление на толкатель а какая часть даже не соприкасается с толкателем ( а точнее соприкасается условно тк даже 5а прогретом двигателе должен оставаться резервный тепловой зазор) и посмотри какую часть распреда он сошлифовал.а сошлифовал он как раз холостую часть распредвала которая в рабочем ходе ( нажиме на толкатель) не участвует . Откуда тогда должен всяться аж дикий износ той части кулачка которая условно говоря даже не трется по сути о другую деталь?
@@filimonfill9046 ты гонишь? Он поставит клапан длиннее.тем самым он выберет зазор, но за счет удлинённого кулачка получится большая высота открывания клапана.
Stumbled across this the other day; its been seen by just about everyone at work. even peoplein the front office think its crazy. well done thanks for the nuk nuks.
Tutti quelli che cristiano non lo sanno fare col tornio puoi fare tutti lavori che vuoi se lo sai usare complimenti a questo signore anche se non taglia le unghie😮
The naysayers on here need to rethink...this guy is the real hotrodder, not someone who can only order from the "comp" catalog and barely know what the specs mean. I bet Ed iskenderian, vic edelbrock, and David vizard tried this sort of thing. The lift is easily measured, and the LCA/LSA didn't really change. Opening/closing and duration could be easily measured, too. He only altered the base circle and opening/closing ramps, so spring pressure is low when rockers are even in contact with the lobe. Flat tappet cam lobes are often slightly conical, to promote lifter rotation, so we know some misalignment is tolerable, his eyeball work in this area doesn't look too bad. This is probably from a little OHC motorcycle, the lobes are giant for the little valves and light spring pressures they have to deal with, I bet they'll have a reasonable life if no valve-piston contact occurs. This clever guy probably owns 5 cheap little motorcycles for the price of the cheapest billet part on your street rod that was built by someone else, with money and a catalog, rather than clever craftsmanship. Again..this guy is the real hotrodder. You should be embarrassed. (I do feel sorry for the leadscrew and ways on that lathe, I'd have covered them!)
i must agree with firty lady you should watch alan milliard turns a 4 cylinder kawasaki 900 into a 6 cylinder cut it in half with a hacksaw and welds it back together makes the cam shaft out or gudgin pins to you (rist pins) but i can see the object of what he done it wasnt like he 15mm off the back of the lobe
As a cam grinder myself the duration and lift must be insanely off but close enough right !! The pioneers started the same way. So I've heard it from the camfather himself Ed iskenderian. It was Trial and error! In the beginning great true stories from the man !
Its the all important acceleration rate from lash to the lift ramp that must be done with care as this is the point in which the rest of the valve train is under the greatest amount of stress and may not cope or reduce longevity and reliability .
Trust me, in those 16hp shit engines, if they get 18 after handgrinding down rha base radius of the cam, they are high preformance gurus in their village....
Just weld the lobe then use it lathe and calipers I done it on a go cart 8 horse it sounds great and took off .60 thousandths off the head and beat of all it runs off hho I got a CO2 on the muffler and map sensor on the intake I use a small bladder tak so when the engine needs more hho the actuator opens up more and it's 12 volts electric start that also runs the fuel cell now I can put my car alternator straight to the shaft 1:1ratio long story short since you got access to lathe and knowledge of all that build one it works don't let other tune videos lie to you good luck and God bless
The surface he grinded does not come in contact with lifter! So no problems with hardening. Done this many times on honda cb 125. You gain lift but little change in timing. These bikes revs 13000 rpm and worked fine after this.
Think about it, this is not bad at all, to get higher opening on the intake/exaust cam he just grinded the useless material which we never consider, instead of replace the entire cam, this way he can add thicker shim on top of the cam to let it open more with the same cam as before...hmm...👍
Grinding down the base circle to increase valve lift and maybe duration is how performance cams have been made from standard camd for a very long time. Much cheaper than starting from a new blank, but limits the cam profiles that can be used, and smaller base circle can cause issues with hydraulic lifters.
@@ferrumignis It can cause issues with any flat tappet lifter in a few ways. If the diameter of the lifter is too small for the profile, the edge can catch the lobe and destroy everything. Mushroom lifters or larger diameter lifters can cure that. On a solid lifter, you need an opening ramp that takes up the lash clearance or the shock can chip and destroy the cam and lifter and a closing ramp to soften valve landing on the seat. Hydraulics also have ramps, but not as pronounced since there is no lash. By cutting the base circle flat, as is done here, the lifter would no longer spin, causing premature wear and failure of either type of flat lifter. A cam that is reground also requires a surface treatment, usually parkerizing.
Ofcurse is not perfect...I get the risk involved...but in some cases 1mm can do some difference in performance without damaging anything..depends how agressive you want to go
@@robertking1032 I was pointing out that a grind not only affects hydraulic lifters, but is more critical for solid lifters. The advantage of increasing lift to probability of cam failure would make this method very debatable. Cams are the most amazing part of an engine due to the abuse they take with hundreds of pounds of spring pressure on the lobe at lift happening hundreds of times per minute, but, they are also one of the easiest parts to destroy. A professionally reground cam is as good as a new cam, but i think done this way, a flat tappet cam would have a very limited life.
@@lelandlewis7207 you hit on the things I had in my mind. I could see this working on a roller setup maybe but not a flat tappet. The wear pattern on a flat tappet would be hard to get right, might could get the circumference smooth enough but the profile across the width of the lobe that aids in lifter rotation would be hard to get right, the taper on the lobe has to mate up with the convex shape on the lifter seat just right in order to spin the lifter and in most applications keep the camshaft seated in one direction of another against a thrust. In the well known sbc the tapered lobe keeps the cam seated to the rear of the engine and the timing gear has a thrust to keep it centered and off the pressed in plug at the rear of the cam tunnel. If one didn't get this profile right it would ride up towards the front of the engine causing timing chain issues, distributor gear issues, and issues keeping the lifter centered on it's lobe. There is more to it than many would think as Mr Lewis has pointed out. A roller cam would negate some of these issues but it's just mite near impossible to do it manually or free hand.
don't forget to change carburation also, it will be hollow at low speed but if you get to high revs it will be good. Bigger main jets, smaller correction jets, to enrich at high speed. Watch the richness at high speed if lean a nice hole in the piston. But don't forget: to be mean you gotta be lean!
Profesional mulai dari resufacing batu gerinda nya tanpa merubah profil tonjolan tapi hanya membuat kondisi tutup lebih dasar sehingga klep akan terbuka sangat tinggi
Жуть! Бедный станок. Его от образива уже колбасит, жёсткость потерял совсем. Чего мучился в начале обкатывал стойкой центр в специальной приспособе когда потом на руках точил самое важное место? Напильником в тисках сразу, чего мучиться.
Я просто ахерел🤯 я реально первый раз вижу тАкое количество абразива на токарном станке 🤣 ты видел как он засыпал каретку поперечки возле направляющих и сами направляющие, и винт подач? 🤯 бл**ь такое ощущение что это не абразив а просто выпал снег, так сказать припорошило😂 Ещё один год и у него такиие пивные бочки будут точить в миллиметр разницы на длине 100мм🤣 а отрезать будут только болгаркой. В общем это диччь Сеня...
@@ДмитрийДобрый-щ7к жа вообще отбитый, я так думаю что если у него есть пескоструй то он пескоструит прям на станке😂 Мы тут значит что-то изгаляемся с тряпками, клиëнками, пытаемся как можно больше закрыть, и то я лично вообще камнями на токарном ничего не желаю, но если даже что-то связанное с абразивом то укутываю станок так как мать родная зимой в детстве не укутывала)) А ему вообще до сраки. Даже если это не его станок то это не повод насрать на него сверху.
I enjoyed the video, but do you have any idea of what the reground specification is , definitely more lift and would have added duration but how much ? Hard to know with free hand finishing. A degree wheel in steps then a free hand dressing would make more predictable results. Great just the same , thanks
The guy couldnt have done all that, those long ass fingernails would have got in the way. All he did was shrink the base line circle, all the duration and timing would remain, but what did happen is he fucked up the valve train geometry guaranteed
@@COLLAR01 The nails were nasty for sure lol. But he never messed up the geometry at all because he actually ground down the base circle of the cam so a $10 set of valve cap shim kits that come in 2 thousand increments he can easily bring it back to the factory valve train geometry.
Go kart racers used to do something similar but they would grind a more aggressive ramp to accelerate the valve open and basically end up floating the valves. Worked really well when you are forced to use the stock components
Если гидрокомпенсатор , то выберет в ноль зазор. Но ребята , если затылок бъёт, то то распредвал выкинуть. Достаточно четыре сотки ямка . Я месяц искал причину из далека сделав диагностику осциллографом и увидев нарушение фаз газораспределения. После обработки надо опять ставить индикатор.
at First I was amazed about the DIY Camshaft Holder you use to do a presize grinding. but later in the end, i was Shock that you just polish it with your own hands. just wondering why did you even exert an effort ysing a DIY Camshaft holder if in the end you will only rely on your bare hands to presizely grind or polish it?
Looks like he done this before..obviously it made a difference to the little china 4 cycle..good effort even if it aint professional by real engine standards..i would have just spent 10mins with a grinder and flap disc for a quick test
What do you know about hardening? If he have it in his hand its probably not very hot and as you probably dont know the tool steel after being quenched goes through tempering cycle 2times to relieve stress and becomes resistant to below tempering heat and beside that , this camshaft is not made from high hardness steel at around 55hrc typically...
Потому что нокоть в слесарные и в малярка это и съемник и пинцет и много функциональный инструмент. А ещё если стричь ногти на рабочих пальцах, то когда он сточится от использования будет мясо торчать и будет весьма неприятно.
I would agree but based in a couple other videos I would guess that he does that. This method is essentially the same as what is called a stock reground cam that is used in classes requiring stock parts, especially in garden tractor pulling. Tools are probably more sophisticated though.
Cara para de desmerecer noso país e por gente medíocre igual você que o país não vai pra frente pra falar mal fala mais fazer algo melhor que é bom nada ne você que é uma vergonha pra nos
Vì bản thân gối cam nó lệch tâm. (lệch trọng lượng cân bằng) nên người ta cố tình để cho phần đố diện gối cam lớn hơn để giảm độ lệch trọng lượng. vậy mà bạn đem vớt lại cho tròn lẳng. vậy khi ráp máy nổ lên tăng ga đầu bò run như chó nắc. sai quá sai.
Lebih enak pake yg model gerinda duduk kayaknya dan di pasang busur+ 2 dial buat center top, lift, LSA, durasi dan LC Tp maklum jg sih itu kerjaan mekanik mesin, kalo tukang bubut suruh bikin sedetail itu malah penghasilan harianya ga dapet kcuali copy cam
Thợ vườn chế cháo hơn hàng chục kỹ sư giáo sư thừa hưởng bao nhiêu thế hệ. sao ko đặt câu hỏi là ban đầu tại sao họ không cho mở wan cao luôn đi. bạn chỉ muốn mở wan lên cao, nhưng bạn không nghĩ đến tải nặng lên sên cam, ép mạnh lò xo supap vòng quay gối cam sẽ không được trơn vì áp lực xuống thấp đẩy lên cao... vậy hổi mở wan cao tăng tốc được bao nhiêu và bao nhiêu áp lực bị hảm lại vậy tăng được bao nhiêu công suất. giảm độ bền, sai kỷ thuât. nghĩ cạn làm càn.
@@Icutmetal what did I misunderstand the cam did not look bad to start with you wouldn't get by with this on a car camshaft it would wear out in five minutes it will probably wear out anyway
The Spintron is a machine used in motorsport to study the valvetrain of a racing engine, it spins the crankshaft and all the internal parts moves like the motor is firing regilarly, but there are not cilinder firing, just spinning. They can film the movement of the valvetrain at the max. Revs permitted by the engine in study, they can collect measured data of various kinds. Probably, the spintron will ask, "what engine are we testing today, 1904 ford model T?"😂
BAD form! This entire job depended on your hand skills being smooth consistent and as little as possible. You hogged off the case hardening by going far to deep! Then faceted (see the lines/steps when he spins it) the the radius with jerky spastic hand motions, and inconstant control. This can work, you blew it. Nothing is square , parallel , or hardened anymore. Its doomed. But hey, this is how you learn, 5 more times and a smooth hand and youll make ones that last for a while.
