• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

rocker arm assembly

Share this page

healeyboz

healeyboz

Jedi Knight
Offline
When installing a head that has over sized valves and springs, do I need different rocker arms and or pedestals. Mine don't seem as if they are going to clear. The springs are definitely touching the pedestals and I think will rub the rocker arms???
 
So I got a hold of the guy who built my head and he said that the factory assembly will work fine. The springs are rubbing the pedestals so badly that I am afraid that I would have to force them into place. This doesn't seem right at all. The rocker arms don't seem that they will clear either. Thoughts? Do I have something in the wrong order?
 
how about a pic?


mark
 
I was just emailing a pic to a buddy of mine. I also took more of the order in which I have everything in, however, I don't think that is it?? I dunno.
 

Attachments

  • 4340-rocker004.jpg
    4340-rocker004.jpg
    160.4 KB · Views: 153
  • 4341-rocker005.jpg
    4341-rocker005.jpg
    76.6 KB · Views: 150
  • 4342-rocker006.jpg
    4342-rocker006.jpg
    73 KB · Views: 132
  • 4343-rocker001.jpg
    4343-rocker001.jpg
    153.2 KB · Views: 120
  • 4344-rocker002.jpg
    4344-rocker002.jpg
    142.9 KB · Views: 117
  • 4345-rocker003.jpg
    4345-rocker003.jpg
    128.9 KB · Views: 128
what are those valves/springs from?
what size are the springs, diameter, hieght?

just how much bigger than stock are they?


sure looks to me like they are not going to fit well at all. Now that this thread is rolling i am sure some of the more experienced folks will chime in shortly. ya might try posting a link to this thread in the racing forum.....


mark
 
To me, the springs look to large in diameter.

I have used isky's without any problems, they visually appear to be 1" in diameter.

Patrick
 
Springs look huge.
 
The diameter is 1 1/4'. I am not sure how to measure the spring height, however, I measured from the base of the pedestal = top of the head and got 1 1/8'. ????????????
 
Those can not be the right springs, they must have gotten mixed up somehow.
 
I measured the isky ones and they are 1 3/32nds. That is 5/32 smaller in diameter then yours. 5/32 *2 is over a quarter inch (.263158) more in clearance for the rocker assemblies.

Patrick
 
Man. Obviously mine are wrong. I will wait and see what he says and get back with all of you. Interesting!!! This kind of stuff explains why I end up doing everything at least twice on this car!! ;(
 
Those are the Comptune style racing oversized valve springs, I recognise them, I sell and use them on the race heads, most of the time with roller rockers. Boz to make them work with your stamped rocker arms, you going to have to modify the rocker arms, this guy should know that, ask me how I know /bcforum/images/%%GRAEMLIN_URL%%/smile.gif You have the clearence them on the underside where they are touching. There is no good reason why those springs were used on a street head, they only come into play with lifts well over .500". I would have went for the little Mini Spare .520 HD valve spring, they are a ton cheaper and will handle lifts up to .520" and are the normal diameter. Your valve spring pockets had to be modified with a special cutter to accomdate those larger spring, I done that many times on a race head.
 
Thanks Hap!! Do you think this head is too much for a street application? I wanted a hotter head with a ?276? cam. But I did not want to lose drive-ability!! Should I loose this head and modify the stock one? If I do use this head, do I have to modify the pedestals as well?

P.S. How do you know? Do you know who built this head?
 
Boz, just what has been done to the head? Do you know the chamber sizes, and do you have flow results for it? All I could tell from the photos was that it was originally a smog 1275 head.
Jeff
 
Like I said I wanted a hotter head for use on the street. I don't know all of the specifics except for what I can see. Trying to use someone else's experience here. It has been ported, milled, larger valves, etc.... and of course the springs.
 
Without knowing the specifics, it's hard to guess if the head will be compatible with the mods done to the engine. You may wind up with a very high compression ratio, for instance.
Jeff
 
Well, because Hap was able to see what was going on, I was able to tell the guy who built this for me. He saw the same pics over email and had no idea what the problem was. He is happy to get this (way to radical for street) head back and send me what I was supposed to get in the first place. He's a pretty stand up guy and as soon as I mentioned comptune he knew what had happened!!

Thanks again to Hap for all if his expertise!!! The man really knows what he is talking about!!!!
 
Back
Top