NEW Valve Spring Design for 604 Engines
We all asked and they listened
Its no secret that the valve spring quality in the 604 engines has been less than desirable and without a doubt very inconsistent.
That’s about to change as the new design spring has been installed on the newest engines leaving GM and conversion kits for all other 604 engines will be available soon.
This announcement is to inform the racer of the exciting news but also to make all tech officials aware that some engines have already left the warehouse and could possibly show up in competition this weekend.
Any questions regarding a tech situation can be sent to Brad Hibbard by phone or text 330-540-7223 or e mail at brad@race-1.com
Race-1; Sweeney Chevrolet and Pace Performance do not currently have any of the new inventory but expect delivery from GM as early as next week.
Brad Hibbard
www.race-1.com
below is a statement sent to us from GM officials
ladies and Gentlemen:
I have spoken to many of you in the recent past regarding some upgrades we were testing for the #88958604 ( aka CT400 or 8604, or 604) in response to field tech input and racer input regarding the valve train components we have used for the past 10 years. In short, we have experienced valve spring pressure variations, both high and low, that were not meeting customer expectations. We have permanently corrected that issue. We are switching to a "beehive" style spring, currently used by all of our production LS-style performance engines, specifically the LS3 used in the Corvette and Camaro SS models, incorporating stringent quality controls, along with enhanced durability and stability for extended high RPM operation. The details of the cylinder head changes and the resulting new engine part number are explained in the attached memos. (see below)
It has been a real challenge to manage and execute these changes, attempting a transparent transition as we move from one valve spring design to another. We attempted to synchronize the installation of the new head content while balancing existing engine inventory going into the peak of the season. We came pretty close, as the first batch of the new engine (#19318604) was shipped Monday, May 20. The new engine is readily identified externally by the Chevrolet Bowtie emblem engraved on the end of the cylinder head, where GM Performance Parts formerly was. Engines with this head have the"blue beehive" valve springs and components already installed.
This component change was made for valve train stability, durability and consistency, not for an increase in horsepower. Dyno tests have validated our contention that there is no horsepower gain, but there is an improvement in valvetrain stability. Operating and maintenance costs should actually be reduced, as spring life should improve in most cases.
For those racers that want to upgrade their existing heads to incorporate the new beehive valve springs, we have developed a conversion kit, which contains all of the components required to convert an existing engine. The component breakdown is in the attached memo. This is a no-modification, bolt-on conversion. Existing components will continue to be serviced for those that choose to stay with the original valve train.
Since "new" engines will be in the field later this week, they could show up in competition this weekend. We apologize if that seems to be short notice (it is), but again, we were trying to balance inventories, not creating a wildfire demand. It is important to emphasize what the upgrade is designed for, and not that there is a big increase in power. The cylinder head is exactly the same, only the spring components have changed.
From the inception of the sealed racing engine program, we have attempted to maintain a level playing field, building affordable Chevy racing engines on a low-volume production line. We hope you find that this change will continue to insure that level playing field for years to come.
We appreciate your support and partnership in providing affordable racing engines. Chevy Performance intends to continue on this path as long as the sport exists!
Important Note: This message is being sent in advance of a formal product bulletin announcing these changes to our dealers. A formal product bulletin will be distributed next week. We did not want to risk the possibility of a "new 8604" running this weekend and getting DQ for "illegal components". Please make sure that your tech organization is informed and aware of these changes before your next scheduled event.
Good Racing!
604 GM Crate Valve Springs
Started by brad hibbard, May 23 2013 08:16 AM
17 replies to this topic
#1
Posted 23 May 2013 - 08:16 AM
#2
Posted 23 May 2013 - 11:00 AM
Great news,except there goes your marketing group in a short while! 
#3
Posted 23 May 2013 - 11:12 AM
Great news,except there goes your marketing group in a short while!
not sure what you mean
#4
Posted 23 May 2013 - 11:17 AM
He means you won't be able to sell your " staggered special and matched perfect " valve springs anymorenot sure what you mean
#5
Posted 23 May 2013 - 11:35 AM
He means you won't be able to sell your " staggered special and matched perfect " valve springs anymore
That is a good thing for us -----if you think that was a money maker compare the scrap price of a 55 gallon drum full of brand new valve springs to what it cost to fill that drum
#6
Posted 23 May 2013 - 04:43 PM
this is great news.
it was a pain to have to replace them every handful of races, then sort through old used stock to find springs that would be better than the new stock available.
brad , how much longer will these springs last?
#7
Posted 23 May 2013 - 05:52 PM
Doesn't the 602 have the same problem?
And is there a cost increase in the "new" engine?
#8
Posted 23 May 2013 - 06:24 PM
will the 604 springs work on the 602? Reason I'm asking is I have an unsealed 602 and I have access to a bunch of used 604 springs with only a night or 2 on them and i would like to use them if i could.
#9
Posted 23 May 2013 - 07:06 PM
will the 604 springs work on the 602? Reason I'm asking is I have an unsealed 602 and I have access to a bunch of used 604 springs with only a night or 2 on them and i would like to use them if i could.
this belongs in the classifieds!
#10
Posted 23 May 2013 - 07:34 PM
He means you won't be able to sell your " staggered special and matched perfect " valve springs anymore
Exactly!
#11
Posted 23 May 2013 - 09:05 PM
how do you figure? didn't see where he listed nothing for sale.this belongs in the classifieds!
he just had a question.
#13
Posted 24 May 2013 - 06:33 AM
THEADCLAIMSTOBEAPERFORMANCE ENHANCE GM HAS ATTEMPTED TO KEEP A EQUAL ENGINE WITH THEIR R.D IN COMPARISON THE LEGEND MAYBE HONORED BY A SOMEONE COPYING HIS ORIGINAL DECK PLANS THAT HE R.D BUT THEN STATING THAT THEIR PRODUCT IS BETTER WHEN THE INTENT IS TO NEEP THE ENGINES RELIABLE ,AFFORDABLE AND AS EQUAL AND EQUALLY TECHED :rolleyes: :angry: :PWhy not just run these??? ;)
http://www.compperfo...;Category_Code=
#14
Posted 24 May 2013 - 10:54 PM
what the hell did i try to buy or sell
Edited by mcmillen61m, 24 May 2013 - 10:55 PM.
#15
Posted 25 May 2013 - 11:22 AM
will the 604 springs work on the 602? Reason I'm asking is I have an unsealed 602 and I have access to a bunch of used 604 springs with only a night or 2 on them and i would like to use them if i could.
No answer ?
Edited by yenko1, 25 May 2013 - 11:22 AM.
30
#16
Posted 25 May 2013 - 08:07 PM
Nope
#17
Posted 27 May 2013 - 08:25 PM
will the 604 springs work on the 602? Reason I'm asking is I have an unsealed 602 and I have access to a bunch of used 604 springs with only a night or 2 on them and i would like to use them if i could.
sorry for not responding sooner but I do not have mobil internet and have been at Tyler County since friday
the 604 spring will NOT work on the 602 ----it is a different dimension entirely and will cause engine failure
call me if you have any further questions
Brad
330-540-7223
#18
Posted 28 May 2013 - 05:56 PM
thanks alot brad
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