Pushrods, oil pump, spark plugs

[omega1940]

I'm in the process of rebulding my 88. I'm into this rebuld big time and have a few last minute questios from you experts. So far here's what's going into the engine. (I already had a 52 mm Throttle Body, Flowmasters, K&N, etc.)

Scat 383 crankshaft, pistons, rods, rings. Clevite 77 bearings
Accell SuperRam Intake
Accell long-tube runners, polished and ported
Ported plenum
Bosch 24lb. injectors
Crane "Gold" racing rollers
ZZ11 camshaft (duration @ .050 214-227, lift 480-518 Lobe 112)
MSD 6AL ignition
Performance Products HEI Coil
Double Roller timing chain
New Harmonic balancer
New flywheel
Centerforce II Dual Friction Clutch disk, Pres. Plate
Hooker headers-powder coated (special bolts, retainers)
8.5 mm. spark plug wires
Ported heads, new valves, etc

I was cleaning out the engine bay in prep. for the rebuild Monday, and saw the old pushrods. These things probably have 144,000 miles on them. Also the oil pump looks like it is original.

My question(s):

1. Should I get new pushrods and if so, what kind?
2. Should I get a new oil pump? I don't know how much oil pressure this new system will need. Is a new GM stock oil pump okay? (Actually I've already decided to replace it, just want to know if a stock oil pump will be okay.
3. What kinds of plugs? I've used Bosch +4's for 20,000 miles and they seem fine.


Thanks, Mike

PS: Jeff is reprogramming my PROM chip to take care of these mods.

 

[rrubel]

I've been told that when you change rocker arms, you MUST change pushrods - they conform themselves to the arms.

I picked up a set of hardened moly pushrods from Terry Rosebush Racing for about $80/set.

You're doing pretty much what I want to do to mine; I'm getting a different cam and forgoing the headers and crankshaft/pistons for now, but the rest I've either done or will soon be doing (same intake, clutch, etc).

[RICHR]

 

[vader86]

Get hardened pushrods, no brand comes to mind so get whatever as long as theyre hardened.

I'm getting a Melling Oil Pump, but i'm still undecided as to whether i'll get a high volume or high pressure, probably high pressure. And yes, you really should replace it with at least the GM part which is pretty good.

You can use whatever plugs you want, i use Rapidfires.

 

[vette-dude]

Go with new hardened push rods for sure. Second, replace the oil pump with a new one and I would use a high volume-- not a high pressure pump. Make sure your oil pick up is well attached to the pump ( I always brazed my on) and in the correct position for the pan height. You've spent all this $$ on the engine you should spend another few $$ for the pump and pushrods if you want the engine to live. Pushrod failure can send nasty little pieces of metal through the engine in a hurry and and oil pump failure can destroy the whole thing in about three seconds. The plugs are kinda your call. Everyone has a preference and it usually is because of the good luck they have had in their engine. Your engine may have a completely different appetite for a sparkplug so start with what you like and experiment until you find the best choice. Rrubel is correct when he says that when you change the rocker arms you should replace the push rods. The push rods work harden on the ends and the new rocker seats and lifter seats will not be work hardened. Therefore, when you replace the cam it should be with new lifters, pushrods, and rocker arms. I have gotten away with using the old rocker arms and push rods when just changing the cam and lifters but you are putting on new rocker arms so do it all and make it bullet proof. just my $.02.

Randy

 

[omega1940]

Pushrods, Oil Pump & Lifters

Hey thanks a bunch. I ordered some Cromelloy (sp?) "hardened" pushrods from Crane. I buy most of my stuff from www.exoticmuscle.com which is Tempe, so I can pick it up. The owner said that he would order slightly longer pusrods after rechecking the specs on the ZZ11 camshaft. I noticed at the Crane website that they suggest (strongly) that when using hardened pushrods you MUST use guideplates. My guy with Exotic Muscle said I didn't need them with the hydraulic rollers like the Crane Gold Racing rollers I bought. Any thoughts?

Also, on another response someone suggested getting a high volume or high pressure Melling (or other brand) oil pump. I did a search for Melling and found their website and did a lot of research and it seems to me that installing a high pressure or high volume oil pump risks damaging the roller/pushrod process. Apparently the use of such pumps, at least in Stage II engines like the one I am building, too much pressure or volume can force the valves to stay open longer because of the oil pressure coming out of the tip of the pushrod. There were a lot of threads on this website that talked about this and apparently it can cause some damage, and a normal GM OEM oil pump does just fine. Even with the rings in my 88 badly damaged, scarred pistons and all the other problems I had, my oil pressure always stayed right around 40 lbs. or better, even in 110 degree heat down here.

Which brings me to another question. Here in the "Valley of the Sun" we are entering our blisteringly hot season. Between now and October it will be over 100 most of the time, and of course airconditioning will be on all the time. With a the rebuilt engine, what kind of oil should I be using during the break-in period and then after that, given our terrible driving conditions? I was using a synthetic, but a mechanic told me that especially in Arizona, synthetics were problematic for high performance engines because they can damage seals much more than a blend or some traditional, high quality oil, say 30 weight.

It really is amazing that virtually every decision about this rebuild has "begat" 10 other questions, concerns and issues. While there seems to be a right way and a wrong way for many of these issues, a great deal must depend upon the car, the driving habits of the owner, how well it is maintained and all of that.

Thoughts anyone? Vader, you suggested a new high volume or high pressure oil pump. Have you seen the reference I made above to the potential problems?

Thanks,

Mike

 

[vader86]

The GM oil pump is pretty good, i'll give it that. Ive heard of the problems you mentioned, and i'm still up in the air over what i'm going to do as far as oil pumps on my engine in the future. I also havent done enough research into it myself. So for now Id ask people who have a high pressure or volume pump, I dont have direct experience with them so i dont know.

Id ask these questions to the engine builder, and see what he says.

Id also ignore anyone who says that synthetics are bad for performance engines, when the evidence points otherwise. Id be running 10w30 Mobil 1, year round if i were you. Dino oil breaks down at much lower temps than Mobil does, and performance engines are going to run hotter on average. Mobil also doesnt sludge up like dino, so you dont have to worry about that crap building up in cool weather and/or short trips.

HOWEVER, for break-ins you need to use regular dino oil like Castrol GTX (which i always used in other vehicles) at whatever weight the builder recommends. After the break-in period is over you can switch over to Mobil 1, usually thats like 500-1000mi.

 

[SPANISHVETTS]

I was using a synthetic, but a mechanic told me that especially in Arizona, synthetics were problematic for high performance engines because they can damage seals much more than a blend or some traditional, high quality oil, say 30 weight.

We run synthetic in the race cars, the brand changes with sponsorship. After every race a sample from each car goes to the lab. I sneak in some of the Mobil 1 from every oil change on the Vette or one of the bikes. The engine manufactures have never caught on and the test always come back clean. That’s good enough for me.

BTW our temps here average in the high 90s from mid May to Oct
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