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Which Roller Rockers Help?

I've heard the TBI 350 motor is only good for 220hp maybe..

I think stock it's 170hp. Dont know for sure.
I still have to pass a smog test where I live so EGR and all the smog crap still needs to function.

Still looking for roller rockers that will fit under an oem valve cover. If anyone knows please post.

Thanks to all those who have posted!!
 
My machinist that bored my cylinders and rebuilt my head, said my compression went from 8.5 to 9.0 with the flat tops. I should be fine with the stock ecu. but I may look into that later.
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You might have your "machinist" double check the heads. TBI Blazers came stock with 64cc 9.2 to 1 Compression ratio heads. He may be going on the assumption that all Chevy trucks had 76cc heads. Did he CC the heads or check the casting # ?
His compression ratio numbers seem a little off to me.
Easy to tell what heads you have. Check the casting # in the rocker valley in the center of the head. If it ends in 193 you have 64cc chambers= 9.2 to one CR with stock dished pistons. This is how Blazers came stock. They have the light duty 2 bolt main LO5 engine

191 = 76cc chambers. 8.2 to one CR with stock dished pistons. This is the GM 4 bolt main LO5 HD truck engine.
 
When I rebuilt my 1981 350 in the 3/4 ton truck it had a 4 bolt main and 76 cc heads. I noticed it had 194 valves. I decided to replace the stock cam with a Comp Cams 4x4 type ( 0.447 / 0.462 lift )and Comp Cams magnum rocker arms 1.52 ratio roller tipped. Comp Cam made a big deal in their literature that most trucks used small intake valves and stamped rocker arms withless than 1.50 ratio ( to limit performance and extend engine life ). When I checked the ratio the stock rockers were 1.4 ratio.
These currently sell for $147.00 a set (16) and fit under the stock valve cover. They also offer them in 1.6 ratio ($160.00).
That has been 8 years ago. since then ( 2 years ago) I replaced the heads with 2.02, 72 cc heads and reused the rockers. The truck still runs strong.
Bottom line - If the cam has a gross lift less than 0.500" any aftermarket roller "tipped" rocker arm is adequate. If greater than 0.500 lift go with the fancy roller bearing rockers ( and probably tall valve covers).
 
Totaly agree with above post. There is no way you need full roller rocker on a mild 350 specially a TBI. Waste of money IMO.
Stamped or chrome molly roller tip rockers are cheap and will get the job done just fine.
 
If it makes a difference, it's not a waste, if you have the money to do it. Any improvement is still an improvement, regardless of whether it's economical or good bang for buck.
 
Well I guess if you have 3 or 4 hundred dollars laying around to possibly gain a few HP on an engine that will never see over 5Krpm. Then go for it.
As for me. I would rather put money into things that will acually build usable power.
 
Looks like one of China's highest quality set of rockers. Bolt em up! Easy 15 hp gain.:rolleyes:
Why would you want to get valve covers and hide those beautiful rockers?
 
Thunder said:
Looks like one of China's highest quality set of rockers. Bolt em up! Easy 15 hp gain.:rolleyes:
Why would you want to get valve covers and hide those beautiful rockers?
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Lol I have a question into the seller to see where they are made, I was thinking the same. If I dont get these I will continue to use my stock rockers.

My head casting numbers are 14102183 at least that's what I think they are. I had to call and have a friend read them and at the moment the motor is sitting upside down on the engine stand :D I'll have to double check tomorrow. Looking at that casting number looks like 64cc heads. The rquirement for me to switch to flat tops was that I was assured I could run on pump gas,factory ecu,and pass smog test. I purchased the rebuild kit from the machine shop so the $hit better work!!!! I exchanged my heads for these. So to be honest I have no idea what I took off.
 
Those look like an exact copy of the Comp Cams Pro Magnum rockers. All the cheap roller rockers i've seen seem to come apart at the fulcrum and also the roller tips i've seen broken off. Also most roller rockers don't even have needle bearings in the roller tip, it's just a hole through a piece of steel and they call it a roller.
 
Thunder said:
Well I guess if you have 3 or 4 hundred dollars laying around to possibly gain a few HP on an engine that will never see over 5Krpm. Then go for it.
As for me. I would rather put money into things that will acually build usable power.
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http://www.popularhotrodding.com/en...ck/0412em_small_block_chevy_engine/index.html

Do some reading. Big surprise, friction has nothing to do with RPM.

Of course, you completely ignore the fact that stock rockers are very unpredictable in regards to ratio, and as has been posted here, 1.4:1 stock ratio isn't helping things. Oh yes, and the fact that they will live to work on the next motor you install.
 
I think I have decided to go with these
http://cgi.ebay.com/ebaymotors/ws/e...60249886061&ssPageName=ADME:X:AAQ:MOTORS:1123

Still waiting to here back from the seller. I have browsed a few forums and this seller seems to have a good reputation. And people that have bought these from him seem to be happy. This isn't going to be a daily driver. It will be a trail truck and serve towing duty, so I don't have to do these things with the Range Rover.

Thanks guys!!! All the comments are appreciated.
 
Dorian. I never said not to replace the rockers. Where did you get that idea? Nor did I ever recomend using the stock ones. Go back and read my posts I totally agreed with Mike D on his post about using quality roller tip rockers.
Stock rocker arms and springs are the first thing that go in the garbage when I rebuild a head

I was just tryng to get across the point that full roller rockers are way expensive, overkill, window dressing, on a mild flat tappet cammed 350. They are not needed. Nor do they make little if any power over a way cheaper roller tip rocker of the same ratio.

I was just tryng to save nxxtreeme some money he really does not need to spend.
The extra cost of expensive roller rockers and tall valve covers can be better spent on parts that acually build horse power and torque. Like a set of headers.:D
 
I was just pointing out the fact that RPM isn't a very good decision point for rollers. I see where you are coming from...roller tips are cheaper, and do a good job, if that's all you can afford, or want to spend, be happy with the decision. :) Full rollers will hurt nothing. FWIW, on newer (some?) GM engines, the fulcrum is roller, the tip is not.

Unfotunately I've been unable to find a back to back comparison of roller tips and full rollers. It can't do anything but help, assuming weight does not become a factor.

Absolutely agreed on better parts to spend money on if budgeting for the build.
 
dyeager535 said:
Absolutely agreed on better parts to spend money on if budgeting for the build.
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Not really budgeting for the build. But I am budgeting how much I will spend on a given upgrade. If the full rollers I linked to will work with my oem covers even if the covers have to be modified then I will buy them. Unfortunetly I have not heard back from the seller yet.

Spending $300 for a set of roller rockers and another $100 on valve covers doesn't make sense on a motor I have $682 into on a full rebuild. Now spending $130 makes a little more sense since I would rather use these rockers over using my worn out OEM rockers.

I don't know if I agree that roller tips would be a wiser choice. Most of the friction is in the fulcrum. A roller tip will only prevent valve stem wear. I'm no expert just doing a lot of reading on the net.
 
Reducing friction is good but the roller tip keeping the guides happy is more important. And even more important is to have a QUALITY set of rockers that have the same ratio on all rockers unlike some of the cheap rockers who's ratio can vary quite a bit.
 
Go ahead and buy that Chinese junk. You dont have a high lift cam and a lot of spring pressure so they may hold up ok.
Hey they give you 15 HP.:thumb: Chinese horses may be different than American horses tho......I think they are smaller.

Be sure to budget $250 for a chip. With those 193 heads and flat top pistons and mild cam. You will need one. Espically if you plan on towing. The stock chip fuel curve is too lean to support more than 9.5 to one.
I cant figgure your exact compression ratio because I dont have the measurements needed. But with a .030" over bore you will be somewhere around 9.8 - 10 to one. You could use a thicker and larger bore head gasket to drop the compression ratio. But a new chip burned for your CR and cam would be the best route to go. You do not want to run a 2 bolt main engine lean towing a load up a hill. All the chinese roller rockers in the world wont help you there.
 
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So I went ahead and purchased the roller rockers from skip white. I purchased the 1.52 ratio. Motor goes in tomorrow, rockers will go in some time next week. Then axle gears go in sometime after that.

As far as the heads go it will either work or I will be having some not so kind words with the machine shop. This was discussed at length with him before he picked the parts. He said he builds these same motors all the time and they run fine on pump gas and stock ecu. My motor was bored .40 over. The cyclinder walls were crap, high mileage motor that was not ever taken care of.

The real test will be attaching the 3.5k lb boat and trying to make it up 26 (pretty steep highway hill). Before the rebuild and gears the thing ran like crap pulling itself up the hill. 2 cylinders were 70 psi motor was toast.
 
A word of advice, high compression ratios and towing while climbing a hill don't mix very well. Detonation will become your enemy really fast.
 
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