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I recently bought a set of what I thought were new comp cams roller rockers (1.6 ratio) for my sbc 350 that I'm building. When I got them home and opened the package I noticed that the nuts had been obviously cleaned up and won't fit my studs. Can I get nuts that will fit or do I need to scrap these and get a whole new set. Also, what would be the best pushrods for my set up: 5/8 cam, 1.94 vortech heads?
Could you post a picture of what you've got? We're visual learners here!!
Regards,
Glenn
I unfortunately don't have a camera available.
If the rockers slip over the studs, but the nuts don't fit, then all you need is a set of poly locks the proper size. HOWEVER, no Chevy I know of used a bottleneck stud (Pontiac comes to mind) and there are some aftermarket 1.6 rockers for Pontiacs?????
So the question is "waddayagut?":D
here's a dumb question-how do I know what size the nuts should be?
Here's another one-this is my first "high performance" build. I have a 350 bored .30 over, forged pistons, I believe the cam lift is 550 (its a 5/8 cam), holley strip dominator high rise intake with a 750dp and as I mentioned 1.94 vortech heads....with this application what is the ballpark hp I can expect? Any info would be greatly appreciated.
To "quesstimate" HP you need more imfo, compression ratio, cam lift (for sure), cam duration, intake (dual plane or single plane) just for starters.
The studs on small blocks are usually 3/8", so they would require 3/8" nuts. BUT some builders add 7/16" syuds and for these you would need 7/16" nuts. The firs thing to verify is if the rocker fit the studs properly.
Good Luck
:eek:
The rockers should be stamped with the ratio. Check that first. Then see if the nut fits down in the rocker. Then see if the rocker trunnion fits the stud. You said the nut won't fit the stud. Is the nut too large or too small for the stud?
Here's what you need to convey to us:Quote:
Originally Posted by CJ 613
Piston deck height.
Compressed gasket thickness.
Chamber volume.
Piston part number or description of the crown configuration.
If you don't know how to determine these things, ask. There is a multitude of engine builders on this board who will be happy to explain how to obtain the info.
the bottom end was built when I bought it so I don't know the technical details. Again, any info would be greatly appreciated
also, the rockers are 1.6 ratio. The nuts are too small for the studs.
They are for 3/8" studs. You have 7/16" studs in the heads. Or at least that would be my best guess.
Have you bolted the heads to the short block yet?Quote:
Originally Posted by CJ 613
no, not yet. I'm not sure if I want to run the 1.94s or not yet. I've been told that I may not get the power I'm looking for with them. I may need to go up to a 2.02.
What kind of power number are you looking for?Quote:
Originally Posted by CJ 613
By the way, If the heads aren't on the motor yet, then you have a golden opportunity to measure the piston deck height.
I'm (trying) to get over 400hp. Not sure if the 1.94s will provide that or not.
how do I measure the piston deck height? And again, any response is extremely appreciated. I know I may be biting off more than I can chew but why not right? I love the knowledge everyone is so willing to share and it really helps guys like me. So thanks!!
also, here is a pic of the intake on the block-its not too clear but it gives you somewhat of an idea what I'm working with.
This measurment exercise assumes that you don't own an 8" dial caliper.
With the motor on a stand, tilt it so that one bank is level. Using a steel rule and a set of feeler gauges, we'll find the actual piston deck height. Standing at the side of the block, span the edge of your rule across the bore about 1/4" from the edge of the bore at either the 3 oclock or 9 oclock position. Slide feeler gauge blades between the bottom of the edge of the steel rule and the piston crown. Checking at noon or 6 oclock will allow the piston to rock on its wrist pin and tilt one way or the other, giving you an erroneous reading. 3 or 9 is directly above the pin. Rotate the crank a few degrees backward and forward and re-check your measurement to make sure the piston is at TDC. Do this measurement on each of the four corners of the block to see if there is a slope to the block front to rear and/or a difference from one bank to the other.
ok, thanks tech. When I get the reading I'll repost.
Ok, so here it is: as explained by "tech", I did the measurements with the feeler guage and came up with a strange reading-60 mm from piston tdc to deck height. Now I've been told 350s usually have between 10 and 15. My question: what did I do wrong or what is going on? HELP!!
With your intake combo, single plane intake and 750 Holley on a 350, you should be trying to make power in the 2000 plus RPM range, 2.02 heads will complement this combo, 1.94s are not RPM heads. Also, you need at least 3.73 gears and a 2000 stall for this combo to run good. As is, stock converter and small heads, this intake and carb is going to kill all bottom end torque, sure, it looks cool, but an edelbrock performer intake and smaller carb will give more low end power.
tranny is a rebuilt 3speed manual with a lot of low end torque and 3:73 rears.
also did away with the 1.94 s for a set of 2.02 aluminum heads with 64cc runners... and as always...thanks for the input...its always greatly appreciated
64 CC and flat tops should give you at least 10:1 compression, nice, aluminum heads, manual trans and 3.73, nice combo. With a good cam, you should have 400 HP no problem. I think Comp cams advertised 400 HP with their 292 cam with your combo.
thats what I was looking for-thanks! Now lets hope I don't screw it up putting it all together.
You didn't have the piston at top dead center. The measurement should be somewhere between zero and 0.045". What's with the mm? Get a set of feeler gauges that reads in thousandths of an inch. Wadda you, a foreigner? :LOL:Quote:
Originally Posted by CJ 613
I brought each piston on each 4 corners of the block to TDC. I was "told" that they were in MM (the feelers) and that was the reading. As I said-:o, Ize jes nawt too dang edjamacayted on this heer fast motr billdin stuuufff. TRial and error right?:confused:
ok lets try this again-the reading (AMERICAN) is .023 below deck height. Tech, is there anyway to run all these specs on your dyno?
.023 is normal for a stock block. To get the proper quench (distance between the top of the piston and the surface of the head you want to use a head gasket that is no more than .022 inch thick and no less than .012. That will give you a quench of between .035-.045 which is ideal for controlling detonation. You can push it to .048 if you have to, but it would be better to stay with the .035-.045 parameter which is ideal. Quench is very important thing to consider when building a performance engine. I'm sure techinspector1 will confirm this.
Thanks a lot Rum. The info everyone is so willing to share makes this build much easier and enjoyable. BTW, love the coupe!!!:cool: