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Discussion Starter #1
ok guys...

I don't recall there being a gasket between the cap & the oil pump, but I wanted to be sure.

on the cam - after the cam is installed what holds the cam in place? there is a piece that looks like it could bolt over the cam (surface that looks like a gasket would go there, and also two bolt holes). however, I do not remember removing anything off there, and don't have any bolts for this area. when I disassembled this engine I put everything in baggies, and labeled everything.

so what this looks like is the cam is installed, and then the sproket bolts directly to the cam. am I off the wall here? (this is a one piece rear main with hyd. cam)
 

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There is no gasket between the pump and block. But make sure you put the plastic retainer on the pump that holds the rod that goe's to the dist. There is a retainer that holds the cam in it is a plate that bolts to the block and holds the cam in and then the gear goes on. Do not leave the plate off. ROY
 

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Discussion Starter #3
thanks Roy - on the oil pump I got a shaft will a steel sleave so I don't have to worry about changing that stupid nylong bushing.

I can't not find that retainer anywhere, and I was incredibly careful pulling everything apart. I took on thing off, put it in baggies, and then marked them.
 

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If your block has the machined face for the cam retaining plate it must be a late model block. GM made these blocks so that they can be used with hydralic roller cams and they have this machined surface for the cam retaining plate, However, GM used a lot of these blocks with NON-Roller hydralic cams (primarily in tbi truck engines). If your engine did not originally have a roller cam then you have one of these blocks and you can use a stock type chevy cam with no retaining plate Or you can upgrade to a FACTORY Hydralic roller cam design which includes obtaining the roller lifter guides, Lifter retaining plate (referred to as the "SPIDER"), and the front cam retaining plate. The front of the factory design roller cam is "stepped" to allow for the retaining plate. Hope this cleared up the missing retaining plate question, because you probably didn't miss it, it wasn't there to start with!
 

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Discussion Starter #5
thanks studebaker - yea this is a stock block out of my 89 k5 that I'm putting together, and not it didn't have a roller cam in it. I asked this question on another site, and they told me I didn't need one unless I was using a roller cam too; however, I wasn't sure why that was machined in there.
 

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I go along with Roy every sbc cam that I have removed or replaced had a retaining plate and two bolts to hold it in. The retaing plate is C shaped or half moon shaped and two bolts fasten it to the block.
 

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Just to clarify, I have rebuilt many of these small block chevy engines that have been machined for the roller cam but the factory used standard hydralic cam and lifters that do not require use of the cam retaining plate. . Some of the late model big blocks are this same way only they don't have the retaining plate mounting bolt holes drilled and tapped. I think the reason G.M. did this with early truck TBI engines is that some of the roller cams have too much lift and duration to be compatible with the computers of the late 80's and early 90's truck engines.
 

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Discussion Starter #8
there other thing is I was extremely meticulous with how I took this apart marking everything in baggies etc. and this is the second one of these I've done in 6 months. to make a long story short I am almost 100% positive there was no retaining plate on this.

<a href="http://coloradok5.com/forums/showflat.php?Cat=&Board=blazer4x4&Number=367763&page=&view=&sb=&o=&vc=1" target="_blank">here is the link</a> on the other site that I was mentioning if anybody is interested. this other site is specifially for chevy k series vehicles (69-87 trucks & 69-91 blazers & suburbans).

[ March 30, 2002: Message edited by: solowookie ]</p>
 

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I did not say they did not have engines without plates I said to be sure to put a plate 0n. The ones without plates were low rev low HP engines. On the later models they even put rev limiters on them. You overhaul one and up the cam and the HP and RPM range and you better put a plate or cam button on it.Of course me and david are old and dum but you might look into it because the cost is very low. ROY
 

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Discussion Starter #10
thanks for the FYI Roy... I'll have debate this one out in my mind. this engine is going into my k5 (finishing this so I can get my 1950 chev in the shop) so the RPM's will be low (running RV cam). I will have to decide whether I want to put one in or not.
 

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Ok, not to debate whether or not to use a plate. If memory serves me correct the reason some need plates and others don't depends on the style of cam used. On most engines the cam is set up to pull back into the block when running, so the timing gear is used to locate the cam in the block. The slight angle on the lobes against the lifters do this, also the direction of rotation and the angle of the cut on the distributor drive gear will either pull the cam to, or push it away from the distributor when rotating under load,the load being the oil pump being turned through the dist.gear. Hope this helps in the reason why department. Man just think of all the discussions we'll have in September!!!! :D :D
 

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Discussion Starter #12
I haven't been around for a september yet so I guess I got all the fun ahead of me still! :D :) :D
 

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I had no idea that Chevrolet would do such a silly thing, makes me wonder what would happen after those camshafts wear down. Perhaps this is the best method to ensure an engine will self destruct after so long. What a way to save a dollar.
 

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Stop and think for a minute,if there is no retainer to hold the cam in place,or a button to push it back what keeps it in place? The timing chain won't do it and it can't walk back and forth or the gears on the cam and oil pump would fail along with the cam itself and the lifters. The lifters don't ride centered over the lobes on the cam if they did then they wouldn't rotate and again they would wear out. As far as gears are concerned depending on how they are cut they will when run at 90deg to each other they will push away from each other or pull themselves closer together :p :)
 

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Your block is machined and two threaded holes to bolt the retaining plate in. It would be pretty cheap insurance to just purchase a sbc cam retaining plate and two bolts from GM , probably less than $20 bucks and put it on there, then you won"t have to worry about it. You could probably pick it up at a engine Re-building shop even cheaper. But I believe it would be wise to have it on there.
 

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I think Liquid-larry is correct, I read somewhere that non roller cam lobes had a slight "lean" to them so that the cam is pushed back by the lifters,to keep it from walking.
 

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Hot 57 is right, this taper on the cam lobe not only pushes the cam back it also causes the lifter to spin, ensuring that the lifter face wears evenly and also transfers heat to the oil lubricating it. The only oil on the lifter face is from oil that is being thrown off from the crankshaft, (referred to as crankcase windage).
 
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