Small block Chevy Cylinder Head questions

Lew Silverman · 09-30-2010, 11:37 AM

Greetings!

Took my 461 small-block cylinder heads to the machine shop yesterday. Finally got a matched pair with no problems! My machinist asked me if I wanted to install pushrod guide plates when he does the screw-in studs. The "rulebook" doesn't mention guide plates one way or the other. Are they legal on a 275 HP 327? Does anyone have any suggestions on a valve spring for this combination? It has to be a single with dampner, but is there a required installed height and pressure?

Thanks for your help! (I'm new at this!

)

Lew

Alan Roehrich · 09-30-2010, 12:59 PM

Lew,
I strongly suggest 7/16" screw in studs and guide plates for 3/8" pushrods. Yes, all of that is legal, and as far as I'm concerned, necessary. You need a set of tool steel retainers, they're lighter and stiffer. You need to talk to your cam guy about spring pressure. The days of a specified spring installed height and pressure are long gone.

My concern here is that from what you posted, your machinist appears to not be intimately familiar with Stock Eliminator. A great deal of the "secret" to getting a car to run in Stock is in the heads, and the vast majority of people, even those that do great quality work, do not know what to do to a set of heads for a Stock Eliminator engine. You can give up a ton of power that way. It can mean the difference between a car that struggles to run 3-4 tenths under the index in decent air, and a car that will run 6-7 tenths under the index in crappy air. It is that critical. And given that good castings are very hard to find, you can't afford too many mistakes.

Bimbo Jones · 09-30-2010, 02:05 PM

"My concern here is that from what you posted, your machinist appears to not be intimately familiar with Stock Eliminator." Alan is so correct on this. A friend had to bail me out because I was treating it like just another motor rebuild. Luckily he knew the ins and outs of stocker motor assembley.

richie 2 · 09-30-2010, 02:14 PM

100% CORRECT....get them machined by a stocker "GURU" !!! hate to try to replace those castings.

Dave Ribeiro · 09-30-2010, 03:52 PM

Lew,

Like I told you before , stick with the players who know what to do and it will cost you less in the long run.... Also you won't have to do them again, & again ? There's a reason people go fast and use the proper engine builders to do it ..... All the guys are right on.... Good Luck & call me....

danny waters sr · 09-30-2010, 04:44 PM

Same thing happened to me when i started my 283 a few years back.

ron mattson · 09-30-2010, 09:09 PM

Xactly what Alan said, do it right once you will thank him!!!

Lew Silverman · 10-02-2010, 02:04 AM

Thanks so much for the great information, Alan! I'll pass along the suggestions you made to my machinist. I think part of my problem is not knowing the right questions to ask, but you all make an excellent point. He came highly recommended, although I think his expertise is in NASCAR engines. So maybe I'll have to re-think my plan.

I'm on my way to New Jersey to pick up the blocks I found, with a side trip to Atco. The adventure continues!

Lew

Alan Roehrich · 10-02-2010, 09:54 AM

Lew,
There are quite a few excellent guys out there who do very good work. You can do a perfect valve job on a set of heads for Stock and they can still run like crap, if it isn't the valve job those heads need. With Stock and Super Stock, it is not just doing quality work, but also having years of experience so that you know exactly what work to do. You can do an extremely good quality 3 or 5 angle valve job, but if the angles are wrong and/or you use the wrong valve, it won't run on a Stock engine. Only experience teaches you what a particular set of heads wants, and how good they have to flow to run.

tj310 · 10-11-2010, 01:47 PM

I only have a 2007 nhra rulebook which clearly states "Pushrod guideplates permitted only when item was OEM for engine used" can anyone clarify this Thanx Trevor

09-30-2010, 11:37 AM	#1
Lew Silverman VIP Member Join Date: Mar 2010 Location: Newport News, VA Posts: 1,435 Likes: 371 Liked 129 Times in 59 Posts	Small block Chevy Cylinder Head questions Greetings! Took my 461 small-block cylinder heads to the machine shop yesterday. Finally got a matched pair with no problems! My machinist asked me if I wanted to install pushrod guide plates when he does the screw-in studs. The "rulebook" doesn't mention guide plates one way or the other. Are they legal on a 275 HP 327? Does anyone have any suggestions on a valve spring for this combination? It has to be a single with dampner, but is there a required installed height and pressure? Thanks for your help! (I'm new at this!) Lew __________________ Lew Silverman #2070 "The Wagon Master" N/SA

09-30-2010, 12:59 PM	#2
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,066 Likes: 1,487 Liked 1,630 Times in 378 Posts	Re: Small block Chevy Cylinder Head questions Lew, I strongly suggest 7/16" screw in studs and guide plates for 3/8" pushrods. Yes, all of that is legal, and as far as I'm concerned, necessary. You need a set of tool steel retainers, they're lighter and stiffer. You need to talk to your cam guy about spring pressure. The days of a specified spring installed height and pressure are long gone. My concern here is that from what you posted, your machinist appears to not be intimately familiar with Stock Eliminator. A great deal of the "secret" to getting a car to run in Stock is in the heads, and the vast majority of people, even those that do great quality work, do not know what to do to a set of heads for a Stock Eliminator engine. You can give up a ton of power that way. It can mean the difference between a car that struggles to run 3-4 tenths under the index in decent air, and a car that will run 6-7 tenths under the index in crappy air. It is that critical. And given that good castings are very hard to find, you can't afford too many mistakes. __________________ Alan Roehrich 212A G/S

09-30-2010, 02:05 PM	#3
Bimbo Jones Member Join Date: Nov 2008 Posts: 109 Likes: 0 Liked 0 Times in 0 Posts	Re: Small block Chevy Cylinder Head questions "My concern here is that from what you posted, your machinist appears to not be intimately familiar with Stock Eliminator." Alan is so correct on this. A friend had to bail me out because I was treating it like just another motor rebuild. Luckily he knew the ins and outs of stocker motor assembley.

09-30-2010, 02:14 PM	#4
richie 2 Senior Member Join Date: Feb 2009 Posts: 963 Likes: 409 Liked 199 Times in 90 Posts	Re: Small block Chevy Cylinder Head questions 100% CORRECT....get them machined by a stocker "GURU" !!! hate to try to replace those castings.

09-30-2010, 03:52 PM	#5
Dave Ribeiro VIP Member Join Date: Sep 2002 Location: Williamsburg, Va.---USA Posts: 1,827 Likes: 1,612 Liked 56 Times in 27 Posts	Re: Small block Chevy Cylinder Head questions Lew, Like I told you before , stick with the players who know what to do and it will cost you less in the long run.... Also you won't have to do them again, & again ? There's a reason people go fast and use the proper engine builders to do it ..... All the guys are right on.... Good Luck & call me.... __________________ Dave Ribeiro 1033 STK

09-30-2010, 04:44 PM	#6
danny waters sr VIP Member Join Date: Apr 2007 Location: lagrange,nc Posts: 2,224 Likes: 1 Liked 0 Times in 0 Posts	Re: Small block Chevy Cylinder Head questions Same thing happened to me when i started my 283 a few years back. __________________ Danny Waters, Sr / 73 Duster "340"

09-30-2010, 09:09 PM	#7
ron mattson Member Join Date: Nov 2005 Location: cloquet mn Posts: 462 Likes: 17 Liked 65 Times in 28 Posts	Re: Small block Chevy Cylinder Head questions Xactly what Alan said, do it right once you will thank him!!! __________________ Ron Mattson 5015 STK

10-02-2010, 02:04 AM	#8
Lew Silverman VIP Member Join Date: Mar 2010 Location: Newport News, VA Posts: 1,435 Likes: 371 Liked 129 Times in 59 Posts	Re: Small block Chevy Cylinder Head questions Thanks so much for the great information, Alan! I'll pass along the suggestions you made to my machinist. I think part of my problem is not knowing the right questions to ask, but you all make an excellent point. He came highly recommended, although I think his expertise is in NASCAR engines. So maybe I'll have to re-think my plan. I'm on my way to New Jersey to pick up the blocks I found, with a side trip to Atco. The adventure continues! Lew __________________ Lew Silverman #2070 "The Wagon Master" N/SA

10-02-2010, 09:54 AM	#9
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,066 Likes: 1,487 Liked 1,630 Times in 378 Posts	Re: Small block Chevy Cylinder Head questions Lew, There are quite a few excellent guys out there who do very good work. You can do a perfect valve job on a set of heads for Stock and they can still run like crap, if it isn't the valve job those heads need. With Stock and Super Stock, it is not just doing quality work, but also having years of experience so that you know exactly what work to do. You can do an extremely good quality 3 or 5 angle valve job, but if the angles are wrong and/or you use the wrong valve, it won't run on a Stock engine. Only experience teaches you what a particular set of heads wants, and how good they have to flow to run. __________________ Alan Roehrich 212A G/S

10-11-2010, 01:47 PM	#10
tj310 Member Join Date: Sep 2009 Location: Dresden On. Canada Posts: 460 Likes: 0 Liked 0 Times in 0 Posts	Re: Small block Chevy Cylinder Head questions I only have a 2007 nhra rulebook which clearly states "Pushrod guideplates permitted only when item was OEM for engine used" can anyone clarify this Thanx Trevor