I recently assembled the new valves. also put some new springs from Fierostore to be able to manage the higher lift from the 1.6 roller rockers. (The performance model)
The new springs seem to have a smaller flat spring inside wound in the opposite direction of the mainspring. The old one has some kind of expanding centerpiece. I dont think that it is possible to reuse the centerpiece due to the fact that the flat springs take up all the space there, so I left it out. I hope that it was the right assumption ?
I have two photos here:
The old spring and centerpiece:
The new performance springs installed:
[This message has been edited by kjelle69 (edited 03-03-2008).]
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06:52 AM
PFF
System Bot
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
yes, the old centerpeice does not get used. the old centerpeice and the new reverse coiled spring do the same job: keeps the spring from curving sodeways when compressed.
something to make sure of: spring install height. you need to measure from the base of the spring to the bottom of the retainer. make sure you have 1.70" or whatever that is in metric. if you have less than that - there is a chance the spring will bind when compressed. and - if it binds - it will wreck soemthing - most likely your camshaft.
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08:28 AM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
Sounds horrifying ! The springs are supposed to work together with the 1.6 lifters. Can you explain more in detail how to measure the spring compression height ?
Is it the unloaded spring ? Or the installed spring height ?Is it ok if it is less or more ?
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08:34 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
installed spring height - it is basicly the hieght of the spring as it is installed. that pic above - measure the spring, only the spring, from top to bottom, as it sits installed.
usually - it is fine. the height is a minimum. and, for most performance springs I have seen for the Fiero - it is 1.70" unfortunatly, it is not easy to measure. there are all kinds of things in the way. dieally, you want to do this BEFORE you install the springs. get a block at the specified hieght, and stick it where the springs would go, and see if it fits.
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08:43 AM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
So it's actually not depending on the spring itself it's rather the base of the spring seat and the length of the valve from the seat to the keeper slot that determines the spring height ! Am I right here ?
It must be rather easy to measure with a vernier caliper. Just a question of using the deep measurement tool.
Metric: 4,318 cm
[This message has been edited by kjelle69 (edited 03-03-2008).]
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09:26 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
Originally posted by kjelle69: So it's actually not depending on the spring itself it's rather the base of the spring seat and the length of the valve from the seat to the keeper slot that determines the spring height ! Am I right here ?
It must be rather easy to measure with a vernier caliper. Just a question of using the deep measurement tool.
Metric: 4,318 cm
exactly right. the hieght of the base pad to the bottom of the retainer pad. easiest to measure WITHOUT the spring in place. yes - most springs is 1.70" or 4.318 cm - but should be on the packaging or instructions somewhere. and, again - its a minimum - if more, not bad. if less - VERY bad.
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10:05 AM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
yup - you are measuring the right area. the 1.7" is a average guess. some manufacturers are more, some less - but MOST I have seen - are 1.7"
I think the springs sold at the Fiero Store are Crane spings, and the install hieght is 1.71" and, again - the hieght is a minimum. if it is less - the spring seat must be machined/lowered. it is a quick & easy job. for me to get both heads done was under $40. and - it will save your cam.
there are also "offset keepers" - them little 1/2's which hold the retainer in place, which can adjust the height also. not sure where you get them tho.
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10:50 AM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
Now this is very important and may ruin my plans of installing everything this weekend. :-(
You said in another post : -------------- ok, the "usual" instal height of Fiero valve springs is 1.700 these springs bind at 1.153 that means at most 0.547 lift. with ZERO tolerance. --------------
I wont get 0.547 Lift with stock cam and 1.6 rockers right ? So there must be some tolerance here ?
The minimum height seem to be 1.650 on one of the intakes, how much tolerance does that leave me ?
//Kjelle
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11:42 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
Originally posted by kjelle69: Now this is very important and may ruin my plans of installing everything this weekend. :-(
You said in another post : -------------- ok, the "usual" instal height of Fiero valve springs is 1.700 these springs bind at 1.153 that means at most 0.547 lift. with ZERO tolerance. --------------
I wont get 0.547 Lift with stock cam and 1.6 rockers right ? So there must be some tolerance here ?
The minimum height seem to be 1.650 on one of the intakes, how much tolerance does that leave me ?
//Kjelle
I dont know the stock cams profile, so I cant answer that. your thinking is mostly correct. since you dont achive that lift, you wont hit the bind point. but, the other issue with the install hieght is the increased spring load. the more it is compressed, the more tension it puts on the valvetrain.
yes - you will probably be OK. some quick math: sping hieght 1.650 bind point 1.153 max lift = 0.497
0.420 (guess) lift on stock cam / 1.5 (stock ratio) * 1.6 (new ratio) = 0.448 new lift
0.049 room for error. but, there is also the increased spring pressure. and, were these numbers for the same springs? I think they are, not sure tho.
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12:03 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
From Fierostore they claim that: "The installed spring height should be approximately 1.7" to achieve 100lbs of spring pressure." Not anything mantioned about binding but as you described the pressure put on the valve train.
I think I'll go with my old keepers, they seem to increase the height slightly, and they only have around 50000 mileson them. so... I have never heard of a failure due to the keepers, have you ?
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12:41 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
When I try to interpret which setup is stock Fiero it seems to be the one with note 18, GM L44
It seems that the lift is different on the intake and exhaust, the intake is 0.420 and the exhaust is 0.437 with 1.6 ratio rockers. With stock rockers it seems that the lif tis a mere: Intake 0.394 and Exhaust 0.410
So the Exhaust must cope with a lift of 0.437
The worst exhaust ISH is 1.687.
If binding occurs at 1.153 then this leaves me with a possible lift of 0,534 here.
When I had these springs with the 1.6 rockers they turned and scraped against the head and slowly shaved off the metal and it made my cam go out, the lobes wore off it, went through 3 cams till I found the problem.
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02:05 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
When I had these springs with the 1.6 rockers they turned and scraped against the head and slowly shaved off the metal and it made my cam go out, the lobes wore off it, went through 3 cams till I found the problem.
is this even possible?? you sure they werent binding & pressing into the head? and that same binding wrecking the cam?
YES, there have been many failures due to keepers comming loose ,you can eyeball them for uniformity,also tap each stem with a plastic hammer or block of wood ...Normally just eyeballing will do,, do not forget to check spring gap when compressed,,between spings when compressed.. I can not remember gap probably about .060 at least.. the coils should not touch near the center ,,and if you run roller rockers make sure at mid lift the roller is centered on every stem ,this seems to be a neglected check...only a slight deviation is allowed.. I had looked at the grind seat marking on the face of the valve.on a previous post,, did not know if this was finished grinding seat mark but it was to narrow???..
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02:40 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
Quote: "The spring travel must always be at least .060" greater than the full lift of the valve. This safety margin of .060" (or more) is necessary to avoid the dangers of coil bind and over-stressing the spring. If coil bind occurs, the resulting mechanical interference will severely damage the camshaft and valvetrain components."
[This message has been edited by kjelle69 (edited 03-03-2008).]
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04:29 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
WOW !! that is the way to go for modifications,keep records...Im impressed..Are you an engineer?? or a mechanical technician of some sort..I bow to Pyrthians vastly superior knowledge ,, he seems to always know his stuff..I can only dream to have this kind of knowledge about fiero,s Ask the machine shop about width of band around face of valve the valve I saw had to smalll a band around the face(the bevel seat) it was the size of a medium bic ball point pen.. it should be 3 medium strokes wide side by side,minimum,,all valves face should be the exact width,, you seem to be a perfectionist ,,this will result in top horse power from your modifications,, Did you recieve the P M (2) I sent to you about face band width??? For peak roller performance you must have the roller at mid lift right in the center of the valve stem ,,I have mention this in other post because no one else has !! you can be off a small amount .. this is difficult to ajust.. some times you have to switch rollers,,mark the center of the stem and eyeball this should be mentioned in the literature from the company,, you have to make sure none of the rollers come to close to the edge,, this is combination eyeball and dial indicator stuff ...quality has improved from years past,,so you should be O K with an eyeball check BUT check
[This message has been edited by uhlanstan (edited 03-04-2008).]
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12:13 AM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
Yes I must admit I am a research engineer in the mining industry in northern Sweden. So I really like technical issues :-)
I would like to hear someone that has a succesfull story of 1.6 rockers installation , I get nightmares with all this risks with new lifters on old camshafts, and ISH too low rendering ruined cams and all that... :,-(
The band of the valves is now wider. The exhaust is somewhat wider than the intakes, but i would say that the intakes are 2.5 - 3.5 strokes with your medium pen.
The center of roller issue: is it even possible to adjust this ? Maybe by knocking hard at the bolt that keeps the rocker in place ? I will however check the position and if necessary switch rockers. Good point !
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02:40 AM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
""FLAT-TAPPET" Open pressures should not exceed 330# open pressure (sustained after spring break-in) for accepable cam and lifter life. a. Open pressures should be a minimum of 220# for applications up to 4000 RPM. b. For good performance above 4000, open pressures should be at least 260# with stock weight valves. (Lightweight valves require less spring open pressure.) c. Spring open pressures over 280# can cause "pressed-in" studs to come loose; therefore,we recommend screw-in studs for open pressures above 280#."
All statements are ok. minimum 220 not exceeding 330 some of the valves have over 280, but the fiero does not have pressed in studs.
Also I read that the tolerance to binding should be over 0.060" and the worst I have is 0.077" so all numbers are leanig towards a GO.
The Crane catalogue also says:
1) "FLAT-TAPPET" cam/lifter applications (Street & Street/Strip) seat pressures a. Small Block 105-125# Seat Pressure b. Big Block 115-130# Seat Pressure (Note: Big Block applications need higher seat pressures due to their larger, heavier valves.)
I have a seat pressure span from 101 to 124#
Which statement is ok for the Fiero ? We have bigger valves than normal V6 engines due to the HO option ? I will also reconsider changing all keepers to old ones, that should put me even closer to the safe side.
Jazzman stated that I should also reconsider using the old hydraulic lifters to minimize the risk of camshaft wear...
What is the proper way of breaking in valve train ? Molykote paste on everything and 4000 rpm's in 30 minutes or ????
[This message has been edited by kjelle69 (edited 03-04-2008).]
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02:53 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
I've only learned this thru the destruction of many cams.....I wrecked 3 in a row due to spring install height - which forced me to learn about it
breaking in the cam: this is fun. yes, there are "break-in" gels, pastes & goos to put on the cam & lifters. dont worry about what ya use - it will all be scraped off as soon as the motor starts. most manufacturers recommend 2000 RPM for break in. and min 15 minutes. anything beyond that is just fine. 4000 for 30 min will be fine. a bit much - but will be fine. there is no specific magic rpm, or time. most engine manufacturers now just fire it up, and redline it, then shut it down and call it done. change oil after done.
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08:35 AM
Francis T Member
Posts: 6620 From: spotsylvania va. usa Registered: Oct 2003
I think the springs sold at the Fiero Store are Crane spings, and the install hieght is 1.71" and, again - the hieght is a minimum. if it is less - the spring seat must be machined/lowered. it is a quick & easy job. for me to get both heads done was under $40. and - it will save your cam.
there are also "offset keepers" - them little 1/2's which hold the retainer in place, which can adjust the height also. not sure where you get them tho.
When I rebuilt my engine, the 3 or 4 of Crane I got were way too HIGH, we had machine the heads! You'd think something that is sould as a Hight Proformance product would be closer to spec, but them we are talking Crane.
Originally posted by Francis T: When I rebuilt my engine, the 3 or 4 of Crane I got were way too HIGH, we had machine the heads! You'd think something that is sould as a Hight Proformance product would be closer to spec, but them we are talking Crane.
Crane has nothign to do with the install height. its is a function of the length of the valve, and the hardware which holds it in place and the spring seat. as mentioned, there are also "offset keepers" which you can use to adjust the hieght. and, from what I have seen, few heads actually need machining for these springs. yes, mine did. I dont think Kjelles will. and, if we did a poll - I'd expect most did not need it. actually - I expect most didnt check, and just happened to be fine - or have wrecked cams, and never knew why.
Do not knock or hit studs,any mod to the valve train should include screw in studs but do not worry about this now,,Performance valve train mods can be tricky,,ASKING advise is the best tool you have when you are inexperienced,or experienced..most do not realize that extra lift rockers add stress to the stem and guides that a hi lift cam would not this is more of a factor on full modified OR the novice who tries to hit the hi rpms that the increased breathing allows,,EYE ball studs before any work !! if in doubt use straight edge to check.. you should have no problem with the position of the rollers,eyeball..this was more of a problem when they first hit the market..IT IS SPRING BINDING THAT DOES IN THE AVERAGE BUILDER even with good installation tech ...Binding does in many a home builder,yes you have done a lot of work and want to complete,,measure & check.. do do not be afraid to remove a valve retainer (cap) and sand it down to get extra spring height,GET the height,,yes I said sand it down be as uniform as possible,,you can file then finish sand,,your system will be more stressed because of the rollers and springs.. I,m sure you are O K now on the valve face seat width as you have a fresh surface,ask a local auto machinist I will leave the numbers to others who have the proper sheet info from crane or comp You are a long way from a speed shop with offset spring retainers, so do not be afraid to sand ,lightens the train ha ha precision and attention to detail add horsepower and reliability a roller that runs to close to the edge can cause a serious problem To sand a retainer with a volcano in the center you drill a hole in a block of wood,didn,t say it was easy valve train modification starts with a new or excellent timing chain ,most important sometime its easier to just switch springs,retainers or valve to attain proper height I use to run light weight lifters and cut or drill for less weight,,,,careful here NEVER cut corners or save time on modifications,think about the time required to pull engine again and start over If close better to use machine shop than sand & file this is for small amount to bring all to equal specification or to prevent binding There is an auto machine shop in your area of Lappland??? or does the mine have facility
[This message has been edited by uhlanstan (edited 03-04-2008).]
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10:44 AM
Francis T Member
Posts: 6620 From: spotsylvania va. usa Registered: Oct 2003
Crane has nothign to do with the install height. its is a function of the length of the valve, and the hardware which holds it in place and the spring seat. as mentioned, there are also "offset keepers" which you can use to adjust the hieght. and, from what I have seen, few heads actually need machining for these springs. yes, mine did. I dont think Kjelles will. and, if we did a poll - I'd expect most did not need it. actually - I expect most didnt check, and just happened to be fine - or have wrecked cams, and never knew why.
Well I'm not expert in this department so you likey correct, however when we measured all the springs some were a lot taller than others. H.P. Works did my machining and they work mainly on race cars and know what they are doing. BTW:They are the ones that work with my son to build his 540+HP 13k RPM 2ltr MR2. It was in the top ten of Sport Compac mag, altimate sreet machine comp. Hope to go there next week to use their dyno, place is like a candy store so many awesume cars.
Originally posted by Francis T: Well I'm not expert in this department so you likey correct, however when we measured all the springs some were a lot taller than others. H.P. Works did my machining and they work mainly on race cars and know what they are doing. BTW:They are the ones that work with my son to build his 540+HP 13k RPM 2ltr MR2. It was in the top ten of Sport Compac mag, altimate sreet machine comp. Hope to go there next week to use their dyno, place is like a candy store so many awesume cars.
all the springs should be the same hieght. it sure sounds like some sort of part mix-up.
Remember, height of the spring is measured at the spring, not compared to the springs around it. It's common to cut spring seats down to make sure the spring is at correct installed height, as it is also common to use shims under the springs for the same end result.
JazzMan
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03:25 PM
PFF
System Bot
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
Anyone that knows where to find offset keepers ? This seems to be the easiest and cheapest way really .
I have an own 3-in one mill lathe drill, I am thinking of milling away one mm of the spring seats that are worst.
Uhlanstan, when you say sand a bit on the retainer, do you mean the two C shaped keepers, or the conical hole in the plate that keeps the spring down ? (Increase the conical volume ?
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03:34 PM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
Originally posted by kjelle69: Anyone that knows where to find offset keepers ? This seems to be the easiest and cheapest way really .
I have an own 3-in one mill lathe drill, I am thinking of milling away one mm of the spring seats that are worst.
Uhlanstan, when you say sand a bit on the retainer, do you mean the two C shaped keepers, or the conical hole in the plate that keeps the spring down ? (Increase the conical volume ?
all three are good answers - they will all accomplish getting a little more height. no, I dont know where to get the offset keepers - yes - sounds like the easiest answer. milling is the usual fix - and works well. the valve seats are flat with the head surface. while sanding/shaving the retainer may work - I worry about strength. you did the math, and know the load each retainer is put thru, and multiply that by RPM's & expected engine live - thats a long time of holding back much force. but - also, at the angle them keepers are at - it dont take much to get that 1mm you are looking for.
edit - heres a link to summit racing - they have all kinds of valve locks (as they call them) http://store.summitracing.c...25232+115+4294860918 I only noticed 2 in that pile of locks which are specificly offset keepers.
[This message has been edited by Pyrthian (edited 03-04-2008).]
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03:46 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
Must new (Standard Design) lifters always be installed on a new camshaft?
YES! All new standard hydraulic and mechanical camshafts must have new lifters installed. The face of these lifters have a slight crown, and the mating lobe surface they ride on has been ground with a slight taper. The purpose of this is to create a "spinning" of the lifter as it rides on the lobe. This is necessary to prevent premature wear of the lifter and lobe.
Therefore, these parts will be mated to one another during the initial break-in period. Used lifters will not mate properly, causing the lobe to fail. If you are rebuilding an engine and plan to re-use the existing cam and lifters (in the same block) it can be done, as long as the lifter goes back on the same lobe it is mated to. To keep your components in order, a Crane Cams "Organizer Tray" part number 99015-1 would be helpful. If the lifters get mixed up, they cannot be used, and a new set will be required. The new lifters would also have to go through the break-in procedure to mate to the old cam.
Also:
Crane Cams does not recommend the use of synthetic oils during the initial break-in period for a new camshaft. Use a good quality grade of naturally formulated motor oil during this period. If you choose to use synthetic oil after the engine has been broken in, change the oil filter and follow the oil manufacturer's instructions.
How have you people with experience conducted a good break in procedure on the GM V6 ?
[This message has been edited by kjelle69 (edited 03-04-2008).]
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04:02 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
Why do camshafts fail? The camshaft itself is rarely to blame for cam failure. When the cam core is made at the casting foundry, all the lobes are flame hardened to a depth below the barrel of the core, allowing the cam grinder to finish grind the lobes to an acceptable shape while maintaining the correct hardness. Here's a list of common mistakes we have determined to cause camshaft failure:
1. Lobe Wear Use only the manufacturer recommended lubricant, which is generally included with the cam. This lubricant must be applied to every cam lobe surface, and to the bottom of every lifter face of all flat tappet cams. Roller tappet cams only require engine oil to be applied to the lifters and cam. Also, apply the lubricant to the distributor drive gears on the cam and distributor.
2. Incorrect Break-In Procedure After the correct break-in lubricant is applied to the cam and lifters, fill the crankcase with fresh, non-synthetic oil. Prime the oil system with a priming tool and an electric drill so that all oil passages and the oil filter are full. Preset the ignition timing and prime the fuel system. Fill the cooling system. Start the engine. The engine should start quickly and run between 1,500 and 3,000 rpm.
If the engine will not start, don't continue to crank for long periods as this can shorten the life of the cam. Check for the cause of the problem and correct it. The engine should start quickly and be run between 1,500 to 3,000 rpm. Vary the rpm up and down in this rpm range for 20 minutes. During break-in, verify that the pushrods are rotating, as this will show that the lifters are also rotating. If the lifters don't rotate, the cam lobe and lifter will fail. Sometimes you may need to help spin the pushrod to start the rotation process.
3. Always Use New Lifters With A Flat Tappet Cam If you are removing a good used flat tappet cam and lifters and are planning to use them again in the same (or another) engine, you must keep the lifters in the order they were removed from the cam they were on. Lifters "mate" to their specific lobes and can't be changed. If the used lifters get mixed up, discard them, install a new set of lifters, and break in the cam in again. You can use new lifters on a good used cam, but never use used lifters on a new cam.
4. Incorrect Valve Spring Pressure Recommended valve spring seat pressure for most street-type flat tappet cams is between 85-105 lbs. More radical street and race applications may use valve spring seat pressure between 105-130 lbs. For street hydraulic roller cams, seat pressure should range from 105-140 lbs. Mechanical street roller cams should not exceed 150 lbs. Race roller cams with high valve lift and spring pressure are not recommended for street use, because of a lack of oil splash onto the cam at low speed running. Springs must be assembled to the manufacturer’s recommended height. Never install springs without verifying the correct assembled height and pressures. NOTE: Increased spring pressure from a spring change and/or increased valve lift can hinder lifter rotation during cam break-in. Decreasing spring pressure during break-in can be accomplished by using a shorter ratio rocker arm to lower the valve lift and/or removing the inner spring if dual springs are being used.
5. Mechanical Interference A. Spring coil bind. This is when all of the coils of the spring contact each other before the valve fully lifts. Valve springs should be capable of traveling at least .060" more than the valve lift of the cam from its assembled height. B. Retainer to seal/valve guide boss interference. At least .060" clearance is required between the bottom of the retainer and the seal or the top of the valve guide when the valve is at full lift. C. Valve to piston interference. This occurs when a change in cam specs (lift, duration, or centerline) is enough to cause the valve and piston to contact. Also, increased valve size or surfacing the block and/or cylinder head may cause this problem. Minimum recommended clearances are .080" intake and .100" exhaust. D. Rocker arm slot to stud interference. As you increase valve lift, the rocker arm swings farther on its axis. Therefore, the slot in the bottom of the rocker arm may run out of travel and the end of the slot will contact the stud and stop movement. The slot in the rocker arm must be able to travel at least .060" more than the full lift of the valve.
6. Distributor Gear Wear The main cause for distributor gear wear is the use of high volume or high pressure oil pumps. If these types of oil pumps are used, reduced cam and distributor gear life will result. However, you can increase the gear life by adding more oil flow over the gear area to help cool off the point of contact.
7. Camshaft End Play Some engines use a thrust plate to control the forward and backward movement of the camshaft in the block. The recommended amount of end play on these types of engines is between .003" to .008". Many factors can cause end play to change. When installing a new cam, timing gears, or thrust plates, be sure to verify end play after the cam bolts are torqued to factory specs. If the end play is excessive, it will cause the cam to move back in the block, causing the side of the lobe to contact an adjacent lifter.
8. Broken Dowel Pins Or Keys The dowel pin or Woodruff key does not drive the cam; the torque of the timing gear bolts against the front of the cam does. Reasons for the dowel pin or key failing are: Bolts not being torqued to correct specs, incorrect bolts of a lower grade stretching and losing torque, not using the correct hardened washer which may distort and cause torque of the bolt to change, LocTite not being used, or some interference with the cam, lifters, or connecting rods causing the cam to stop rotation.
9. Broken Cam A broken camshaft is usually caused by a connecting rod or other rotating part coming loose and striking it. Sometimes the cam will break after a short time of use because of a crack or fracture in the cam due to rough handling during shipping or improper handling prior to installation.
[This message has been edited by kjelle69 (edited 03-04-2008).]
This is a measure you use when all else fails you can grind a small amount from the retainers also known as caps or spring lids,, these are the top pieces that resemble a volcano.. you can only grind the flat surface ,, the retainer(cap) is the piece that presses the keepers(locks) to the valve stem and presses against the upper valve spring..do not do this unless you must.. I would measure the springs .. you have the measurement,on your excel paper of the compressed spring now remeasure the springs so you can put a short spring where needed.,,or a longer valve where it is needed when you change a lot of stock parts ,for performance parts you often find more work than planned.. the valve seat face grind mark should be centered on the engine head valve seat, or very close,on a race engine you make a lap and check the fine bic point mark and move valves to attain proper seat but this is not necessary on a street engine...keep used valves in same hole
never alter the locks (keepers) on a street engine,, you can check spring retainers and if there is a lot of metal below where the keeper locks are in the "fasten" state you can grind this off ,,coat bare metal with oil.. (I blue them) you want your retainers to be all the same weight
used valves will be different length,but should be kept in original hole UNLESS you can avoid binding by change the cam makers will have the keeper locks,in different models... up/ down
the .060 was a lucky guess,,I did not know
locating the rocker is done by moving mounting points,combining different lenth push rods & vavle stems,, or changing rockers
the rocker will start out close to center and at mid lift should be mid stem and pull close to the inner stem at full open consult the data they sent to you.. The lift should be equal on each valve intake same exhaust same get your close this is a lot of work to do properly
the more equal the more uniform the more precise the better running engine the more reliable
you are not building a race engine,, only in spring clearance you must have more than enough
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02:21 AM
daveg Member
Posts: 193 From: Barrie, Ontario, Canada Registered: May 2004
I would avoid the use of Crane springs with 1.6 rockers. I have had my engine apart several times after their springs failed.
Now with Manley springs it revs freely to redline (a bored and stroked motor, heavily ported head with custom oversized valves, 10:1 compression and with stock intake plenum too!). It has been 3 years and counting with these springs.
daveg
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07:33 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
5. Mechanical Interference A. Spring coil bind. This is when all of the coils of the spring contact each other before the valve fully lifts. Valve springs should be capable of traveling at least .060" more than the valve lift of the cam from its assembled height. B. Retainer to seal/valve guide boss interference. At least .060" clearance is required between the bottom of the retainer and the seal or the top of the valve guide when the valve is at full lift. C. Valve to piston interference. This occurs when a change in cam specs (lift, duration, or centerline) is enough to cause the valve and piston to contact. Also, increased valve size or surfacing the block and/or cylinder head may cause this problem. Minimum recommended clearances are .080" intake and .100" exhaust. D. Rocker arm slot to stud interference. As you increase valve lift, the rocker arm swings farther on its axis. Therefore, the slot in the bottom of the rocker arm may run out of travel and the end of the slot will contact the stud and stop movement. The slot in the rocker arm must be able to travel at least .060" more than the full lift of the valve. ......
going by this and your table above - looks like you are all set to continue assembly
YAY!
you are doing some fine work
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08:41 AM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
As I understand the Fiero Store performance spring is not Crane springs. Anyone that know what type they really are ? And... do they have a good reputation to last?
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12:55 PM
kjelle69 Member
Posts: 201 From: Koskullskulle,Lappland,Sweden Registered: Feb 2004
