Rank: Member
Groups: Registered
Joined: 7/02/2010(UTC)
Posts: 4
|
Hi I just purchased a 186 engine that was out of an old sprint car. The guy I bought it from said he didnt know anything about it apart from "it went really hard" and that it was only pulled out because an engine builder sold them a cheap worked 202 that another customer couldnt pay for. The engine looks to have had some serious balancing work done and looks in very good order. I wanted to know about the head, it has big double valve springs and after looking at a few old cast yella terra heads it looks very close, can anyone help? Numbers on it are 7429477
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 7/02/2010(UTC)
Posts: 4
|
Thought some more info might help. When you are looking at the intake ports where the head stud goes through, its not a cast piece but it looks like a hollow metal rod was used. Would appreciate any help as IM very new to the early holdens
|
|
|
|
|
|
Rank: Veteran
Groups: Registered
Joined: 26/02/2009(UTC)
Posts: 1,647
Thanks: 16 times
Was thanked: 27 time(s) in 25 post(s)
|
Its just a 186 HR head. yella terra they have a hollow metal rod.
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 13/01/2006(UTC)
Posts: 303
|
YT modified original Holden castings...so th epart number will point to it being a HR head (or whatever type...but is no definative way to put your hand on your heart and say it is a YT head...they are the usual features like dual valve springs, YT on the valves and hogged out inlet ports....but they cant be IDed by numbers...even though a cluey guy on another forum spotted a stamped number on the back of the head that YT "might have stamped there..its on the face that would be closest to the firewall...its not a proven thing...but Holden wouldnt have domne it I dont think.
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 7/02/2010(UTC)
Posts: 4
|
thankyou for the reply i will look at the back of the head and c if i can find anything. the valves on the other hand have double springs but not one marking on them
thanks again
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 14/06/2007(UTC)
Posts: 582
|
The YT marking is on the face of the valves. Its not uncommon to find YT "style" heads. Cutting out the casting around the head bolts and running a thin steel tube is standard practice for Holden 6 heads.
End of the day it doesnt matter if its a YT or just a modified head, as long as it goes well!
"Silly modern cars" |
"Silly modern cars" |
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 12/10/2005(UTC)
Posts: 495
|
Im currently machining a 186 head for a work mates HR Ute.
Ill post up some photos a little later, but basically what Im doing for him, is machining out the exhaust seats and fitting Hardnened stainless steel seat inserts, so he can run it on unleaded fuel, and Ive also machined out the head bolt bosses in the inlet ports. No small diameter tubes are going in though, what I like to do with these red motor heads is counter bore the base of the cut out boss large enough to use Cap-head bolts as the head bolts, so they sit in there with absolute minimal air flow restrictions. The top of the old boss is then threaded with a 3/8 BSP thread and brass or stainless plugs are screwed in to seal the port off. Only other thing I do with these heads is a little releaving off the ports with a little work with the milling cutter and die grinding to clean up to make all the ports nice and square, and aid in a better flow of the head.
All this can easily be achieved on a standard turret milling machine with the correct cutters, Im lucky enough to have both a turret mill, and a Mira Head Mill.
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 12/10/2005(UTC)
Posts: 495
|
|
|
|
|
|
|
Rank: Member
Groups: Registered
Joined: 7/02/2010(UTC)
Posts: 4
|
I intend fitting a SC14 supercharger to this engine and was after a suggestions. would it b better to fit de-compressed pistons or would it be better to get a low compression head and just sell this one on?
or can anyone suggest a better option?
|
|
|
|
|
|
Forum Jump
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.
