Oldwolf

Hi, I need your advise on what type of valvetrain, adjustable rocker arms i should bye. The engine is 350 cui, high comp, ported big valve 5 heads and I,m going to spin it to 6500-7000 rpm.

The cam specifications says 550 valve lift, and aftermarket HP springs.

I have looked at Mondello stuff, wish is a bolt on , but expensive IMO.
What is your advise, and experiense, are Comp:s stamped steel ball and cup rockers the ticket ore should I go the more expensive and difficult way, with a lot of machining.

I Also have a another question in the same ballpark. I notised that Ford smallblock, AMC smallblock and Olds are listed for the same rocker arm at Comp, the red aluminium roller rocker. Do anyone know if thats true, I meen the similarity, for other rockerbrands, for example crane gold rockers?

Please exacuse the spelling.
Stanley

joe_padavano

1.6:1 ratio rockers from a small block Ford will also fit an Olds. Which one to use depends on how much machine work you want to do to the heads. The bolt-on Harlan Sharp paired shaft rockers are very easy to install but pricey. Others require machine work to the heads for larger studs and guide plates. Your call.

70 cutlass s

Summit sells kits for the Olds. It comes with roller rockers, studs, guide plates, and push rods.

Oldwolf

I guess thats The Comp kit you are reffering to, the cup and ball type, not a trunnion type?

Stanley

Oldwolf

Thanks for the information about the similarity between Ford 1:6 rocker and Olds 1:6 rockers. That means atleast that the geometry is the same.

Do you know if its possible to bye rocker studs that fits direktly i the 5/16" mounting holes with enough treads to clamp the guide plates also. 5/16" UNC bottom tread and 3/8" or 7/16" UNF top tread. Where do I find these animals. Brand?, number? As you can understand, it´s not easy to get this in sweden, I Have to order the right ones directly. Therefore my concern.

Stanley

Stanley

70 cutlass s

That's correct that what I like to use its real easy to install and easy to adjust.

Oldwolf

Thanks that sounds good.

Stanley

captjim

This is my opinion, based on my experience working at a machine shop. If you are serious about spinning this up to 7 grand, do not skimp on the valve train. Get 3/8" push rods and a quality roller rocker set up, like the HS. Not cheap, but you will be sacrificing HP and reliability if you don't. I have used the Comp kit on several engines, it's fine on a mild build, but I would not use 5/16" studs, 5/16" push rods, along with the rest of that kit at 7,000 rpm. JMHO.

Oldwolf

Yupp, I think you just poited me the in the wise but more expensive direktion. 7000 rpm is possible with the setup. I will look at the HS-kit. I like your consern about reliability.Thank you.

joe_padavano

What he said. More to the point, the valvetrain is only PART of your problem if you intend to operate in that RPM range.

70 cutlass s

captjim is wright and has very good point. I guess your going to be drag racing. The comp kit is good up to about 6000. What are building car and engine what are your plans.

Oldwolf

My plan is short right now. I bought a started engine projekt. A well prepeard engine block 1968 #2, Bored, decked and cleaned. N-crank 0.010 under, checked and reworked stock rods, and a pair of #5 heads with large valves. Heads are like new, 3 angle valve job, bowl job.

I dont have any plans for dragracing, I want to build a stout and powerful olds 350 engine because I want to se how it turns out. I am going to match it to a 4-speed and after that we will se what I am going to test it in. I have a 442 with a 455 but I´m not going to put it there. Maybee a old Volvo!!. Do you want to see pictures?

Stanley

BIGJERR

If your using stock rods 7000rpm wouldnt be anything I would try.......

The compCams kit is a great bang for the buck....

captjim

That changes things a bit. What pistons are you using? Even with flat tops, Cr will be 10.5 max. So, go with the Comp kit, RPM intake, cam in the 230 @ .050 range, you should be done by 5800 or so, no need to twist it up higher. Set of 4.10s with a 4 speed and you'll have a fun little cruiser! What does a Volvo weigh...........

70 cutlass s

Find you a G body you can find them pretty cheap. If your not drag racing. I don't see much point in turning 7000. You can build a real strong engine that has a power band that starts at a lower rpm. It would be cheaper to build. Something that turns 7000 rpm your just not building a engine you have to build a car that can hold up to it. Sounds like you want to build a toy. That's cool when build an engine you need to keep in mind how it's going to be used, and what it's going to be used in. A G-body making around 350 hp or a little more. Find a good 8.5 rear end and have fun.

Oldwolf

I have 62 cc combustion chambers (checked) so I vas planning on 11:1and a zero deck.For pistons Its not very much to chose from here, only the flattops Speed Pro ZL2320F30. Are there a problem with that?

The camcard says

captjim

No, the Speed Pros are fine for what you are doing. What cam are you using? If you go too much you end up with a car that does not have decent manners, fine on a race car but maybe not for something that you want to drive around. It really depends on what you want to do with the car.

Oldwolf

Crower 56272, 304/312 adv. 244/249 0.050, 540/568 lift, 108 lobe sep. Maybee a bit crazy but I hav´nt tried this yet.
Stanley

captjim

That's a lot of cam for a 350, but with your compression and gears to match, it ought to scream. It'll definitely have a nasty idle, maybe install it a couple of degrees advanced. Not sure about the street manners, though the manual trans will help. Power brakes?

Oldwolf

Power brakes? probably wouldt work properly. As i said before. One thing at the time. Thanks for your concern.

Stanley

captjim

Sorry, I wasn't clear. I was asking if you are intending to run power brakes as vacuum with that cam might be an issue, but it sounds like you already are considering that.

Oldwolf

Sorry, It's my bad spelling. You are right, the power brakes probably dont work with that cam.

Regards
Stanley