428 stroker valve spring recommendation solid roller

[oz fe]

Hi new to this and fe big blocks,purchased a 63 galaxie boxtop with a 428 stroker manual
The car has broken a comp roller rocker,car has diamond pistons +.030 h beam rods,changed top end to edelbrock alloy heads ported restrictors and drains enlarged ,2.19 manly extreme duty valves,comp roller setup ,it came with a crower solid roller specs as follows,dur @50 248/254 651/655 lsa 108 296 du, I purchased all crower new roller lifters, and springs to suit 1.900 installed 212lb seated 560lb open msd & 950qft carb , comp is 11.5;1 trend pushrods also.
I am trying to work out the problem with this , could these springs be too little for this set up?
Had this on dyno and we think must be valve float it only produced 377 hp @ wheels @ 5100?
Currently at a loss with this
I mainly had clevelands over the years and never had these issues
Any idea's would be appreciated

[jayb]

Doesn't sound like valvesprings to me, those should be fine for that cam.  You're not running a point type distributor, are you?  If you are running a good electronic distributor with an MSD or other good ignition box, I'd be thinking the carb is the issue.  What intake manifold and carb are you using?

[oz fe]

Hi the car has a msd mech advance dist with 6al box, bronze gear used
carb is a qft 950
manifold is edelbrock rpm dual plane should be good to 6500
it snapped the exhaust rocker
lash is 22 exh
20 int
tops of valves small indent on top of stem where roller runs
thinking of lash caps
timing @ 36
someone mentioned the ratio of comp rollers  listed as 1.76  when checked was 1.93 ? have you heard of this?
if that was the case would the springs then be not strong enough? only guessing here

[ScotiaFE]

I'd pull out the dist and check the gear.
Those bronze gears pretty much dissolve after a bit.
There are two types of Comp Style rockers. Small and big, as in width.
If your getting a 1.93 ratio I'd call that bonus.

[jayb]

I doubt that it is physically possible to get a 1.93 ratio on the rockers.  You might look at a set of T&D or Harlan Sharp rockers instead of the Comp rockers, they are going to be stronger.

Are you saying that the engine just won't rev past 5100 RPM, or is it just the power level that is the issue?  If its the power level, it could still be the carb.  Sounds like you went to a chassis dyno with the car; did you get air/fuel data?

[oz fe]

Hi yes it was a chasis dyno 12.4 is what was on the screen they said that was where it should be carb didn't even need a rejet all good there
The car would rev to 6000 no problem but power dropped off after say 5200rpm
This is the second broken rocker on this car,1st broken rocker was a dove and it had cast heads on it with same crower solid roller
The second rocker was last w/end 6mth old comp set pt no 1046 hd kit and new alloy top end 6 mths ago crower lifters etc
The heads flow over 300cfm +
The valves have indent/groove where the rollers run on the tip I think that's why they are saying valve float ?

[jayb]

Actually, Dove makes the rockers for Comp Cams, so you've broken two Dove rockers.  You definitely need to upgrade to a better set with those spring pressures.  The indent on the valve stem indicates that the valve tips were not heat treated correctly.  Lash caps would solve that problem, so I would go forward with those, provided they fit; make sure that the lash caps fit all the way down against the tip, and don't bottom on the valve locks instead.  The indentations do not necessarily indicate a valve float condition; I've seen that before where no float was present.  Air/fuel ratio sounds good.  How many cubic inches, around 460?  You should be making around 550 HP with that combination, which would translate to around 450 HP at the rear wheels.  I think Howie's idea to check the distributor gear is a good one; if it is really worn and is allowing the timing to flutter that could be the source of the problem.

[oz fe]

453 cu
dist bronze gear was new 6 mths ago but I will check
I think I will look into a set of the t&d rockers
agreed it should have something around that power that is what I was hoping for & with a better manifold n spacer should be approaching the magic 6"s

[ScotiaFE]

Today the go to gear is the steel gear for use with those hard roller cams.

http://www.summitracing.com/int/parts/msd-85813/overview/make/ford

[oz fe]

Thank you ,I guess I will be changing the dist gear
I think i'll be busy getting all this, new gear, rocker set up etc
While I'm at it should get that crites hood so I can fit a different manifold as well.......
Should play a good tune !!!!!

[blykins]

Can you post the dyno sheet?  Valve float will show up on the curve and numbers...

That cam should get you about a 6500 rpm peak, so something is going on for sure...your open pressure isn't bad, but I would like to see a good bit more seat pressure. 

Do any of the valve stems have "butterfly" patterns on the tops?

[BH107]

Can you post the dyno sheet?  Valve float will show up on the curve and numbers...

That cam should get you about a 6500 rpm peak, so something is going on for sure...your open pressure isn't bad, but I would like to see a good bit more seat pressure. 

Do any of the valve stems have "butterfly" patterns on the tops?

I've looked at using this cam too, as Crower is local to me and I can get a pretty good deal. These springs are actually the stiffer of the 2 they recommend for this cam.

What would you recommend? When I compare it to Comps similar cam their springs are lighter as well.

[blykins]

Here's an engine builder's tip....never look at the cam "notes" or spring specs that are listed in the catalogs.  They have no clue what engine you're working on (could be anything from a 352-511).  They also have no clue how heavy your valves are, what your install height is, or how high the rpms will be given your combination.  It's all generalized and it's a crap shoot.

As for the springs, I would have to know the rest of your build specs.  That particular cam could peak at around 6500 in a 428, or around 6000 in a 482, or maybe higher in a built 390.  Just depends on what it's going in. 

Lots of variables there and they all play a part in spring pressure.  For something like that cam in your run of the mill 427/428, I would like to see at least 230-240 seat and 525-550 open.  You gotta watch about running a lot of open spring pressure with aluminum heads though.  It can pull the rocker studs right out. 

[ToddK]

Hi Oz FE, were abouts in Oz are you? I'm in Perth, and by the sounds of it I have a fairly similar set up to you. Here's a link to my car and engine build: http://fepower.net/simplemachinesforum/index.php?topic=1498.0

[oz fe]

trying to find dyno sheet
butterfly effect on top of valve not all of them have this I think you mean by that is a wear indent on top of the valve in the centre where the rocker roller contacts the tip ? yes
I am in nsw
The black box top looks sweet, wouldn't think there is too many in oz
My 63 box is white ,sounds good when running tho  lol!!

[blykins]

There should be no "wear" on the valve tips.  If so, then as Jay says, there is a hardness issue with the tips. 

[machoneman]

There should be no "wear" on the valve tips.  If so, then as Jay says, there is a hardness issue with the tips.

It seem that more worn valve tips have been commented on in recent years. In most cases, it appears that cheapo SS valves, available for some pretty low prices on E-Bay and through some mail order shops, don't have the proper heat-treat to the tips or are lacking a pressed-in hardened tip. I wonder if our pro engine builders like Brent are seeing more of these failures. 

[blykins]

Not really, but I use SI, REV, Ferrea, and Manley valves.  Not cheap stuff. 

Only issue I've ever had was on a custom hollow stem Ferrea that had a pressed on tip.  I went to put the valve up into the guide to assemble it and when the valve tip went into the guide, it shattered...

At some point it's worthwhile to run a lash cap, but I have run many 600-700 lb open pressure spring combos on the valves listed up above and didn't get any wear. 

[cjshaker]

It seem that more worn valve tips have been commented on in recent years. In most cases, it appears that cheapo SS valves, available for some pretty low prices on E-Bay and through some mail order shops, don't have the proper heat-treat to the tips or are lacking a pressed-in hardened tip.

That's the understatement of the year (and it's early in the year ) Staying away from the cheap junk listed on Ebay is the first step to building a decent engine. Or, in other words, you get what you pay for.

[oz fe]

the valves used in my motor are manley severe duty 427 valves pt no 11884 2.190 3/8''  marks in the top of them
all good top shelf parts used

[jayb]

That's interesting, the last valves I had that happen with were also Manleys, back in 2005.  Strange, because they are usually top shelf parts.

[oz fe]

lash caps I guess will fix this

[jayb]

That's how I fixed it with my engine.

[cjshaker]

the valves used in my motor are manley severe duty 427 valves pt no 11884 2.190 3/8''  marks in the top of them
all good top shelf parts used

I hope you didn't think I was referring to you, Oz. That wasn't the case.

I've used Manleys several times without issues, but even in the aerospace industry and NASA, rare but occasional issues with metallurgy can and do happen.

[oz fe]

no no cj all good I didn't think that