[DeTomaso] Cam problems

[Paul Timko]

I was under the impression that you should only use one of the valve springs 
when breaking the cam.

Paul
#9270

----- Original Message ----- 
From: "F. & D. Terry" <gt5s at bcpl.net>
To: "steve meausette" <panterasteve at shaw.ca>
Cc: "detomaso at realbig.com" <Detomaso at realbig.com>
Sent: Monday, June 05, 2006 2:15 PM
Subject: Re: [DeTomaso] Cam problems


> You may have a problem with the coils binding on your valve springs. The 
> springs must be checked by rotating the engine through one cam revolution 
> to ascertain the minimum coil clearance. Pushrod length is determined by 
> observing that contact is centered with the valve stem.
>
> Fred T.
>
> steve meausette wrote:
>> Hi all,
>>
>> I need some major advice..........  I have just had my second Comp Cam go 
>> flat in my Pantera.  The first one went in about five mins of break-in 
>> time and the second in about ten mins of break-in time.  Both times never 
>> below 2000 rpm.  Both times  new cams (560 lift hydraulic),  the first 
>> time I used Comp Cams lifters (hydraulic) and the second time Crame 
>> lifters (hydraulic).  Push rods were measured and were the right length, 
>> double valve springs (old and weak) when tripple are reccommended for 
>> this grind of cam,  Comp Cams break-in lube the first time and Crane 
>> break-in lube the second time.  I used an oil accumulator (3qt) and the 
>> oil pressure started off at 60lbs and gradually went down to below 20lbs 
>> (new guage) and that's when I shut it off.  Both times.  New oil pump 
>> both times.  I use an engine oil cooler.  Pete Jackson gear drive that 
>> has plenty of clearance, (new).  I pre-lubed the engine before I put the 
>> weber manifold back on (could'nt get anything in the dist
> rib
>>  utor hole after as the webers were in the way) and the oil pumped up 
>> through everything including the new lifters and pushrods (Comp Cams 3/8 
>> pushrods).
>>
>> I am now thinking of using a hydraulic roller cam and lifters.  I 
>> understand that they require no break-in time.  Is this true?  I don't 
>> know what lift and duration etc to use when ordering.  The engine is 
>> bored 30 over with Kieth Black pistons and reworked rods, windage tray, 
>> large oil pan, completely balanced,  Webers and 180 degree headers.  I am 
>> after a rough sounding idle.  The car will not be raced but street 
>> driven.  I have never used a roller cam before.  Are special valve 
>> springs, pushrods etc needed?  Any suggestions on cam manufacturer and 
>> lift, duration etc?  Are any modifications required in the lifter valley 
>> etc?  Any and all help would be greatly appreciated.  This is driving me 
>> nuts not knowing what's causing the problem.  Thanks in advance,
>>
>> Steve
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