Daves03

I have a 1995 firebird trans am im in the process of building this is the first car engine i have built i ordered speedmaster roller rockers and i ordered a new set of pro comp hardend pushrods 7.200 overall length, i ordered the pushrods because mine in the car were pretty beat up from the trashed last engine, i have installed
COMP Cams Xtreme Fuel Injected Camshaft Hydraulic Roller Chevy LT1 5.7L 07-468-8
7/16" Rocker Arm Screw In Stud Kit (2.000" Above Hex)
7 Degree 11/32" Std Install Height Chromoly Valve Locks Keepers
Chevy SBC 350 1.5 Ratio 7/16" SuperStreet Aluminum Roller Rocker Arm Set
Comp Cams 26918-16 High Performance Beehive Valve Springs GM LS1
PC 7.200" Chromoly Hardened Steel 5/16 +0.080" Wall One Piece Pushrods (16/Set)
Speedmaster Chevy SBC 350 Flat Guide Plates 5/16" Pushrod - 7/16" Stud Hole 2pc

i got the 7.200 off one of the pushrods that was in my engine and ordered a new set by that, now with changing the cam the springs and trying to go from original rockers to new roller rockers in the 1.5 ratio im thinking i need different pushrods, i tried installing everything today but when trying to set my initial valve lash i noticed that the base of the roller rocker arm is contacting the rocker stud boss, and causing the rocker to bind, i bought everything with the intention i wasnt going to have to run guide plates but i made the mistake and bought non self aligning roller rockers and had to install guide plates. Can anyone tell me what to do to get this engine together and running im dying to get this car back on the road, if i need a different length of pushrods can someone please give me a length to use from personal experience. Thanks for the advice upfront im open to all comments you guys...and girls have all helped me more than once.

BALLSS

PR length is something you measure "your" set up first, then order. Not something you guess at or assume is the same as another motor with a cam.

With that said the 7.200 will "work" but they "may" be slightly long but you won't know until you measure. Typically people with a new motor where the block has been decked along with the heads and a thinner head gasket you wind up shorter PR

First just mark the valve tip with a Sharpie and lash valve with the 7.200 and see where the witness mark is. If center of tip you are good. If more towards exhaust side they are to long and if more towards intake side they are to short

IDK why you RR is not sitting right on stud...unless you have trunnion on upside down. The flat side faces top.

What brand, part # for RR studs? are they for use with guide plates?

You are better off with guide plates and NSA

That is a big cam and its specs are for using 1:6 RR so with the 1:5 the lift will be less than its spec. All XFI grind cams published specs are with 1:6 ratio unlike all other ones that are 1:5

Daves03

part number for the screw in studs are Procomp Electronics - PCE260.1001

summit racing was the one that recommended the use of the 1.5 instead of the 1.6

Gojira94

iTrader: (4)

242/248 - .547/.542... stock heads, by any chance? Way too much for stock heads. It'll sound pretty nasty, though. Not to hurt your feelings, but the 467 is probably a tad too large as well. The 466 would have been an excellent choice on stock heads and put you in the 340-350RWHP range and run extremely well and quick.

If your pushrod side of the rocker is so low it binds up or can't clear the spring your stud is too short. PR should be resting in the lifter cup for the valve you're setting/ measuring, then place rocker trunion over the stud with the flat spot up for the rocker nut. Put the rocker nut on the stud and thread it slowly on until you feel the tiniest bit of drag while spinning the pushrod with your fingers. Take a picture of that and post it so we can see what you're dealing with.

Gojira94

iTrader: (4)

And... what about fuel injectors and fuel delivery (pump)? You can't feed that engine with stock injectors, volume (lph) of pump is in doubt as well.

Daves03

I will post up some pics later yes I am on stock heads I want something that sounds wicked for now i have polished the heads out and gasket matched to open them up a little. The problem im facing is the rocker is setting so low on my rocker studs the rocker is contacting the shaft of the rocker stud causing it to seize or drag instead of free floating for a smooth operation or adjustment the push rods can't be adjusted because of the binding to see where my pattern falls on the valve stem.

I'm thinking it is a stock fuel pump and fuel injectors but im willing to change them if need be and after getting it running im going to order the tune kit, the engine does have the headers and three inch exhaust with no cats so it should breath real well. I just want something that sounds good for now eventually I want the better heads but 1900.00 for heads is a bit steep right now just trying to get the car going. I figured once I get the new heads I'll also step up to the 1.6 ratio rockers the car is already going to be faster than anything I've ever owned.

BALLSS

you bought some pretty cheap parts...and often get what you pay for

The Summit guy was an idiot for recommending 1:5 with that cam....but that cam is WAY to big for a stock head 350 period.

If you want a poser chop sound cam just get a LT4 Hot cam. It will work ok on stock heads

Daves03

SS RRR

iTrader: (2)

Things that come to mind are improper PR length or torquing the adjusting nuts to 87 fl. lbs.

Daves03

ok so i tried this today because a bunch of people have told me the 7.200 length would work, i removed the rocker studs and pulled the guide plates, lined the rockers up best i could with the valves(NO MORE ROCKER BINDING) marked the top of the valves and went through two turns of the balancer or a full cycle TDC #1 to TDC #1 to makes sure exhaust and intake has opened and closed fully. The pattern im thinking looks a little to the exhaust side. But ill let you guys be the judge. I also measured the guide plate against a ruller and im moving the rocker stud up 3/32 of an inch with the guide plates. So now i just have to get the geometry right with the guide plates in place to hold my push rods in line.



#1 Front left corner of engine

BALLSS

7.150 would be better. If anything you want to "slightly" favor intake side if the sweep is not dead center

The 7.200 will work, their just not perfect

also confirm if the body of RR is not hitting the retainer at any point during motion

Daves03

So i took an old push rod and cut it in half put in a threaded rod and two nuts to be able to lengthen and shorten when i get home I'm going to install that and adjust so i can see exactly what size push rods I need.

BALLSS

Nothing wrong with "rolling your own" for a tool. Use calipers to measure/adjust it to 7.150 and test then try 7.100 to check that. Most PR come in .050 increments so just order what size you wind up with after the length check

Daves03

Ok here's my update,
Reinstalled the guide plates under the studs tried to adjust but the rocker buttons back out on the studs so anything less than 7.2 using the guide plates is so low the rocker sitting on the stud, I tried putting my tool at 7.100 to get an idea and the roller of the rocker looks very much centered the stem with no load. Im thinking two options.

1. Send the current rockers back for self align rockers and remove all guide plates maybe still use 7.100 rods because i was a little to the exhaust side before the -. 100 should bring me closer to center.

2. Someone was talking about caps that sit on top of the valve stem to give a little more length to the stem. This may put me in the ballpark with the 7.200 or 7.100 to still use my guide plates and keep the tmtm rockers i have.

Any other thoughts or anything i have missed?

Daves03

Just wanted to post up a quick update,

Summit racing I ordered the valve lash caps from comp cams I installed two on the tops of my valve stems took my push rods to zero 1/4 turn of preload and rolled the motor over two times for one full cycle intake/exhaust and I have a beautiful line right smack dab in the center of my lash caps from my roller rockers with clearance between the stud and the roller rockers. Win win.