Pistons hitting head.

Old 04-18-2008, 10:56 PM
  #1  
Tod74
Senior Member
RACING JUNKIE
Thread Starter
 
Join Date: Sep 2007
Posts: 4,143
Default Pistons hitting head.

I just bought some new Brodix -2x heads and I went to put them on my motor tonight and they seem to be hitting the head. I put one on last weekend with my old head gaskets to figure out pushrod length. I only put a few bolts in and ran em down snug cause I figured the head gasket was used and would be compressed already.( fp 1017-1) Checked P V Clearance ands all that and it was fine.I didn't use clay used check springs...if I would have used clay I would have caught it before I wasted a head gasket.
So tonight I put one on and after I torqued the bolts I went to turn it over and thud. I can't even roll it over.
:cry:
I took the other head and tried to lay it on the other bank with a piston at tdc and with no gasket I can feel it barely rocking around on the dome....Never thought to do that before cause I just figured they would fit cause my old ones did.( I know never assume)I don't know how I didn't catch it when I did the valve /piston clearance..it rolled over then(not torqued down)I did sorta feel something when I first turned it over...but just figured it was just from siting all winter.....cause I mean it was very very light...now obviously it is clear the piston must have just barely rubbed and then when I torqued the bolts down it hit.
It is obviously hitting the head as visible through spark plug hole.My pistons only have a 36cc dome and the heads are 115 cc chambers. (I got those rather than the 119 because of the relatively small piston dome) .Brodix says they work with all standard pistons. My old 074 heads had been milled to hell and back and they cleared just fine...I even had them on a 454 with the TRW open chamber piston with a 48 cc dome and it was fine. This short block is new but I have ran it some last year with the 074 heads...I don't know off the top of my head how far in the hole the piston is...but it is NOT above the deck. I will have to measure it tomorrow...

What are my options to fix this? I mean I know I could get different pistons or grind the heads but I don't want to do that(grind) cause I don't know what I'm doing and don't want to ruin a brand new set of heads. I know the 1017-2 is .051 thick but this is a dead thud so that wouldn't help I don't think...any advice would be appreciated.

PISTON Are SRP and the PART NUMBER IS 140329


PS. No spark plugs or pushrods installed yet so it isn't that.
I am going to cc one of the heads tomorrow and see what it
actually checks at too.
Tod74 is offline  
Old 04-19-2008, 06:22 AM
  #2  
sc3314
Member
JUNIOR BUILDER
 
Join Date: Jan 2004
Location: Wisconsin
Posts: 65
Default BB2 X tra

This is a pretty common problem with these heads. Either start working on the domes where it hits. Or do what I did made the chamber look like a Dart chamber. Mine hit with a set of Ross pistons.

This sure sucks, but not much to do but fix the problem. I went round and round with Brodix, and Ross. Sent pictures to both of them. Neither one did anything about it!

Good luck!!!!!
sc3314 is offline  
Old 04-19-2008, 06:56 AM
  #3  
Tod74
Senior Member
RACING JUNKIE
Thread Starter
 
Join Date: Sep 2007
Posts: 4,143
Default Re: BB2 X tra

Originally Posted by drz1972ss
This is a pretty common problem with these heads. Either start working on the domes where it hits. Or do what I did made the chamber look like a Dart chamber. Mine hit with a set of Ross pistons.

This sure sucks, but not much to do but fix the problem. I went round and round with Brodix, and Ross. Sent pictures to both of them. Neither one did anything about it!

Good luck!!!!!
I thought this was just more of my classic good luck. Believe me if only one set in 1000 hit...I would have that set. :?


I don't know what a DART chamber looks like...I'll have to look for some pics online.

How much work did ya have to do to the chambers? Where do they hit? I am going to put some dykem on the chambers and roll it over later and see what part it actually hits.




Thanks for the reply.
Tod74 is offline  
Old 04-19-2008, 06:59 AM
  #4  
dcarr511
Member
JUNIOR BUILDER
 
Join Date: Jul 2003
Location: U.S.A.
Posts: 80
Default

I had the same problem with a set of 2X's ..... didnt need no dyekem to tell where they hit that was for sure.

And I did as is described above.
dcarr511 is offline  
Old 04-19-2008, 07:43 AM
  #5  
LuckyDawgRacing
Member
CRAFTSMAN
 
Join Date: Apr 2006
Posts: 53
Default

I had same problem last year. actually ran the aky engine. I ended up simply grinding the chambers at the point of contact. took care of the problem. on my set i didn't get technical just ground chambers. did this in about a hour. I run 8's with no more problems
LuckyDawgRacing is offline  
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service