[DeTomaso] Hydraulic lifter pressure hole location

[Daniel C Jones]

You should be okay as long as you are under the rim.

Dan Jones

On Mon, May 24, 2010 at 5:10 PM, Doug Braun <doug at silicondesigns.com> wrote:
> Under the edge by that amount.
>
> Doug
>
> -----Original Message-----
> From: detomaso-bounces at realbig.com
> [mailto:detomaso-bounces at realbig.com]On Behalf Of Daniel C Jones
> Sent: Monday, May 24, 2010 2:52 PM
> To: DeTomaso Forum
> Subject: Re: [DeTomaso] Hydraulic lifter pressure hole location
>
>
> Do you mean that your under the chamfer edge by 0.015" or above the
> lip by the same amount?
>
> Dan Jones
>
> On Mon, May 24, 2010 at 4:41 PM, Doug Braun <doug at silicondesigns.com> wrote:
>> Dan,
>>
>> I'm running the Crane 36532 hydraulic roller link-bar lifters so I agree
>> that in theory I shouldn't have a problem.  But being the type that likes
> to
>> double check everything in an engine build I took some measurements.
>  These
>> measurements show that the top of the lifter pressure holes rise to
> between
>> 0.015" and 0.040" of just entering the chamfered area of the lifter bore.
>> The 0.015" measurement is the worst one I found.  The question is, is this
>> normal and/or OK to run with?
>>
>> Doug
>>
>> -----Original Message-----
>> From: detomaso-bounces at realbig.com
>> [mailto:detomaso-bounces at realbig.com]On Behalf Of Daniel C Jones
>> Sent: Monday, May 24, 2010 12:55 PM
>> To: DeTomaso Forum
>> Subject: Re: [DeTomaso] Hydraulic lifter pressure hole location
>>
>>
>>> What's the recommendation on how close the pressure hole on a hydraulic
>>> roller lifter can get to the top of the lifter bore and still be safe?
>>> As you go with a cam with taller lift, the hole gets closer and closer to
>>> coming out of the bore.  I talking about how close the hole can safely
> get
>>> to the edge of the chamfer at the top of the lifter bore where
> pressurized
>>> oil will just begin to leak.  I want to check this on my new stroker
> motor
>>> to be safe.
>>
>> It varies from block-to-block and depends upon the size of the chamfer
>> at the top of the lifter bore but, on many blocks, the oil feed is exposed
>> at maximum lobe lift.  Some manufacturers (like Comp) will reduce the
>> base circle of the cam so the OEM type lifters can be used.  As a rule,
>> irregardless of how much lift that a camshaft has, the lifters generally
>> all stop in approximately the same location at the top unless the base
>> circle is deliberately reduced which can cause problems at the other end
>> of the lifter bores.  With a reduced base circle cam, the OEM lifters
>> will usually be safe at maximum lift but some blocks will have
> interference
>> problems with the dogbones.  A local shop has a fixture to machine the
>> block for clearance but it can also be done by hand.  Comps link bar
>> lifters have the oil feed (and associated band on the lifter) in the same
>> place as the OEM lifters so have the same problems at max lobe lift.
>>
>> The Crane/FRPP link bar retrofit hydraulic roller lifters have the oil
>> feed placed lower on the lifter body and do not have the max lift problem.
>> Erson also makes a couple of link bar lifters (one a less expensive street
>> version and the other a more expensive race version) but I've not been
>> able to verify them for fit.
>>
>> Dan Jones
>>
>>
>>
> _______________________________________________
>
> Detomaso Forum Managed by POCA
>
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
>
> DeTomaso mailing list
> DeTomaso at list.realbig.com
> http://list.realbig.com/mailman/listinfo/detomaso
>
>
>
>