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hotrodharley 08-20-2009 07:25 PM

push rods
 
i have a customer that built his own bbc but couldn't get running right.bought it to me to get going before the weekend[has a car show this coming weekend]i found that the pushrods are to short due to he has a set of pro comp heads on it.read about them he they said they are thicker surface on them to handle superchargers and turbos so that is telling me they are taller then stock cast heads.does anyone on here have a set of these heads on there bbc and would know what length pushrods they had to go with?

OneBadGMC 08-20-2009 08:15 PM

Re: push rods
 

Originally Posted by hotrodharley
i have a customer that built his own bbc but couldn't get running right.bought it to me to get going before the weekend[has a car show this coming weekend]i found that the pushrods are to short due to he has a set of pro comp heads on it.read about them he they said they are thicker surface on them to handle superchargers and turbos so that is telling me they are taller then stock cast heads.does anyone on here have a set of these heads on there bbc and would know what length pushrods they had to go with?

What push rods they had to go with is moot. Push rods will be custom length for ANY engine, specific to that build. This is assuming you want proper push rod geometry.

http://www.compcams.com/information/Products/Pushrods/

There's a better article out there regarding setting the length. I'll see if I can dig it up.

cepx111 08-20-2009 08:38 PM

CC makes pushrods in a vast array of lengths just for setting proper "rocker arm" geometry.

You'll need a adjustable pushrod, some large dial or digital calipers, and some lay out dye.

WJ is correct, every build is different, however with most aftermarket heads a .100 longer pushrod will get you in the ball park.

Cp

OneBadGMC 08-20-2009 09:05 PM

http://www.mid-lift.com/TECH/TECH-Installed-G1.htm

There's what I was lookin for. If you use that site's information for determining push rod length, you'll maximize valve guide life.

hotrodharley 08-21-2009 12:06 AM

i know about checking push rod lengths.this isn't a race car.it is just a stock engine with a lumpy cam and heads and lot of polished alum. and chrome for a show car and street crurseing.just hopping some had these heads already and could tell me what they had to use for pushrods.

cepx111 08-21-2009 11:00 PM


Originally Posted by hotrodharley
i know about checking push rod lengths.this isn't a race car.it is just a stock engine with a lumpy cam and heads and lot of polished alum. and chrome for a show car and street crurseing.just hopping some had these heads already and could tell me what they had to use for pushrods.


You have a PM

oldandtired 08-24-2009 12:50 PM

Re: push rods
 

Originally Posted by OneBadGMC
Push rods will be custom length for ANY engine, specific to that build. This is assuming you want proper push rod geometry.

x2 One of the most time consuming task in blueprinting is measuring the roller tip motion over the valve tip (or lash caps).
To properly do it you must measure each cam lobe base. Then with a known pushrod length, check variances to see if you have any of the following:
1. Valve seat ground too deep (or too shallow).
2. Valve tip ground too much (or too little).
This occurs after you have shimmed your springs to the correct height.

The last item I purchase for a build is the pushrods. Dave


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