multi groove valves, solid cam question

[winton 399]

Will it be a issue using multi groove valves short term with a solid cam? I have crow locks and retainers fitted , basically just want to run in the cam in before I pull the motor down.

[slydog 7,873]

There a issue with high rpm and seeing as your only running a cam in which means low rpm you will be fine.Just no big spring pressures and no big revs are the only rules.

[winton 399]

Thanks Rob , yep just made this primitive looking thing to remove my inner valve springs.

[PRO250 1,506]

I ran multi grooves for 2 years in my old engine it had a 600thow solid in it and 130 350 at 600 springs in it. im not saying run with it this is just how long they lasted for me

One thing i always did was take a very good look at the valve tip every time i checked the rockers, and somtimes pull some springs to look at the groves in the end they did start to  bur up the groove but that was about 25.000km in  

No one did a off the shelf single groove valve for a 250 back when i started with them in 2003 so i ran what i could find, they will last for a while just keep looking at them. standed valves seem to be a no no i tryed it a while ago and they pull them thru very fast i had to replace valves before 5000km standed valves dont seem to be any good for big springs and revs but cheap fun and took a fair while to rack up 5000km on that engine

[winton 399]

Thanks Dave.

I was hoping someone would have past experience like this , I don't plan on leaving them in there long but this gives me some confidence about the time they will be in there.

I move slow so it could be 12 months before I get around to getting the valves changed, between now and then the car will have little use and won't see the road.

[ando76 4,354]

I have run multi groove valves on my speedway engines for the last 6 years without an issue.  This engine has .584" lift and regularly sees 6000 rpm for extended periods and I have never had an issue, even using old locks. 

 

The reason is that I have good (Isky) valve springs and correct pressures.  If you run massive seat and open pressure then single groove valves with quality locks are mandatory - and seeing as most people over spring their engines this seems to be the reason for their recommendation.

 

So to answer your question - no there will not be an issue to use them in the short time.

[PRO250 1,506]

well thats good info

what is considered over sprung?


 

[slydog 7,873]

Back in the day,Dick Johnson's brother made a spring testing jig with a strobe light to see what was really happening under load and RPM with various springs.After some testing they went to lighter springs then they had been using on there clevo's previously.They never said how much lighter but they always worked and DJR never had engine failures.

 

Says something...  

[ando76 4,354]

Yes Sly and guess which cam profile they used in their Bathurst engines - Tighe 392C.

 

PRO 250 - this is going to scare you and probably most others but I only run 105-110 on the seat and I should be running 95 according to my now departed mentor GT.  I just couldn't run pressures that low so he said "well go to 110 if it makes you feel better but 95 is plenty."  That is using Isky 235D springs with 584" lift on a Tighe 392C.  Its a package thing.  The springs have to suit the cam - ramp rate etc. but I am confident that you could run15-20lb lighter than most recommended spring pressures - provided you use quality springs.

 

Why use a lighter spring - less mechanical effort = more power.  They only need to lift and return to the seat - not hammer a new seat each time they are closed.  Having said that we don't want to under spring.  Its a matter of trying stuff and seeing what works - being sensible in the process.

 

I have always favoured Isky springs.  Cam my other mentor who does heaps of High Performance stuff now and when he worked for Bill Mann at Performance Wholesale said any serious stuff they always went Isky. 

 

I change my isky springs after 4 seasons as I find they lose 5lb of seat pressure in that time.  Not bad really considering the absolute punishing they get.  In a street/strip engine they would out live me. 

[ando76 4,354]

oh and I use dirty old austral valves as well PRO 250, nothing flash.  time for another GT quote 'You get the valve springs right - you can fuking run nails for valves!!!"

[slydog 7,873]

Yes Sly and guess which cam profile they used in their Bathurst engines - Tighe 392C.

 

 

I just lost all respect for them now...LOL That would have been 1 of Ivan grinds too I'd guess.Very smart man for all reports Dean however...

[winton 399]

Thanks for your input Ando.

This thread is has become a good read for all (I think), I googled my original question and about all I could find was peoples opinions without any past experiences on the matter.

 

Cheers Sly, Pro, Ando

[slydog 7,873]

Thats what it's all about bred...helping each other.

[ando76 4,354]

I just lost all respect for them now...LOL That would have been 1 of Ivan grinds too I'd guess.Very smart man for all reports Dean however...

Very smart and still goes into the factory every Saturday at 82 years old.  Dean is a complex person, that is for sure, but I have never had an issue with him and he is a wealth of knowledge - when you get him talking.  I admit that with GT on my side I had a little 'in' there as GT and Dean spoke regularly and GT's first wife still works in the office at Tighe. 

 

I guess I have always used their products as they are Queensland based and I have had good success with their cams and when you want a roller for a crossflow - they all start life at Tighe. 

 

no worries winton - happy to share my experience.  I have a love (some would say unhealthy) of these engines and their giant killing antics. 

[Clevo120Y 815]

You can get away with less spring pressure if the spring resonance frequency is high, the higher the frequency the later in the rev range the spring goes into surge/float.

[winton 399]

Well got the new cam in not with out a few stuff ups. Somehow I got the oil slinger caught in the chain, be fucked if I know how that happened. Also I must of lent on the choke, ran like shit when I started it took me a bit till I find the choke closed. That number 1 lifter what a pain in the arse, took me about 20 minutes. Lost a push rod think it fell down a oil drain hole, found it hugging the block hiding under the head gasket. All worked out in the end though .

[slydog 7,873]

Wow...have seen or heard of that but glad it all worked out for ya.Was it easy to dial in?

[winton 399]

Didn't dial it in, I'm pulling the engine out next , need to raised the comp so I'm pulling down the engine and having it decked plus adding a stud kit. Figure with the cam fitted I can measure the clearances to see how much I have to play with. The engine has dun bugger all ks since I built it and i only got minimal taken off the deck when I had the machining done, I'll be using the same bearing when I put it back together , now that the cam is run in I figure I can just drop it in and go. I'll set it up properly when I put it back together .

[PRO250 1,506]

Number 4 intake is screaming coil bind did you check that? did you look to see the ratainers dont hit the valve guide boss ive seen that to

If you swaped the cam with the engine together how do you know theres enough piston to valve clearance? im all for sticking in a cam, but at 600 lift i start looking at these things as thats getting big

I also have to ask how do you know the heads not flat on its arse at 500 lift as most are? dont get me worng ive done it. It looks like it can go easy 12s going by the parts shown but ive had a few of them that just dont work and you stick the head on a bench and it will not flow thats why most bigger engines you see make mega good numbers for a small say 230@50 cam but you fit a 250@50 cam and it makes less power, ive been there a few times, althow you can fix that when you pull the head off. 

Just being constructive in no way is any of that a chop. your having a go and and you have a corty GO CORTY!
 

[ando76 4,354]

Gee I don't know Dave. looks like there is a least .060 between the coils on 4 to me and 5 ex is down further and there appears to be plenty there as well.  I look for .060 between at least one of the coils.  I think the spring locators make it look worse than it is.

 

I have a .594" lift cam in BTIZA and I had plenty of PTV even with zero deck and a unmarked head with a bit off it.  Still managed to smash a valve or two into the piston mind you thanks to shit springs and high revs - bloody valve float. 

 

Seems the OP is only going to run the cam in and then pull the engine apart anyway - although this seems a bit backwards to me but hey each to their own.

[slydog 7,873]

Coil bind is something I like steer away from and have ALOT more installed height (spring height) then needed as at RPM loads and stresses rise and inertia harmonics and valve control become blurred.I over spring and use as much installed height as possible personally but mainly cos I have what would be considered heavy valves now days.Id like to see you measure the bind and Id bet inlet is closer then exhaust.All mine have been...?

Still if it has been run and your pulling it down there is plenty of time to check stuff out.I have been in your shoes and my run in process would have you pull your hair out but try to remember the people who have replied are doing so because they see where your @ and are trying to help.

I however can not stress enough how important it is to dial a cam in and am only to happy to help if needed.

[wagoon 2,429]

try to remember the people who have replied are doing so because they see where your @ and are trying to help.

 

I however can not stress enough how important it is to dial a cam in and am only to happy to help if needed.

I am not one of these people that have been there and done that. BUT I have done a lot of reading and asked questions until people want to hit me. Every person that has responded so far I have asked questions of and they have been very kind with there time and advise. It has been made perfectly clear that dialing in a cam is as important as correct tension of bolts inside an engine. Even placing the cam dot to dot is like assembling an engine with a rattle gun, it may be close but more than likely its way off. I can't tell you technically why like the others can but I can say that it not good.

[PRO250 1,506]

Gee I don't know Dave. looks like there is a least .060 between the coils on 4 to me and 5 ex is down further and there appears to be plenty there as well.  I look for .060 between at least one of the coils.  I think the spring locators make it look worse than it is.

 

I have a .594" lift cam in BTIZA and I had plenty of PTV even with zero deck and a unmarked head with a bit off it.  Still managed to smash a valve or two into the piston mind you thanks to shit springs and high revs - bloody valve float. 

 

Seems the OP is only going to run the cam in and then pull the engine apart anyway - although this seems a bit backwards to me but hey each to their own.

Your screen must be better then mine its looking close, the exhaust looks like theres plenty but the intake apart from the top coil is looking close, but may be my screen 

 

Its hard being a keborad warrior somtimes you cant always see the pictures

 

Winton how much room in the springs and how much cam?

[winton 399]

Dave

Didn't measure the coil bind just a visual check, thought it looked fine but I will measure it now.

PTV, just assumed because I had bugger all off the deck last build.

 

As for the head, yeah I'm going to have it flowed and work done to it. How well it flows now I don't know , apparently its a Dave Adams head but I didn't get it from him so I can't say for sure, also I had it reconditioned by Chris Milton engine developments and they said it was the best xf head they had ever seen, weather the guy was genuine or just blowing smoke up my arse I don't know.

 

Ando

yeah I'm backwards.

 

Question and might sound stooopid , "zero deck hight" Would this be the term used for the deck flush to the pistons at TDC?

[winton 399]

Dave i'll measure and get back to yas