roller cam for 1.65 rockers

[TurboBob]

I am slowly collecting parts to build up my other engine. The plan is to swap my current heads onto the other shortblock when I do the swap.

I'm currently running a 204/204 baby roller with the 1.65's and it runs well. The new engine will be set up for more RPM, and I am thinking of a 212/212 cam.

If I keep the 1.65's, I worry about having too much lift for the iron heads. Is there any data about how much lift is too much for the stock heads. I drive mainly on the street, so I put a fair amount of miles on and want good valve guide durability.

Bob

 

[Mike Licht]

It depends on how much the guides are machined and what springs your using. There is also some lobes that have the duration and less lift that will work.
Mike

 

[Slow91z]

I have a 218/218 in my car with 1.65 rockers and iron heads with no issues so far. The lift with the rockers comes too just under .550. I'm pretty sure the exhaust guide has just been cut down to the size of the intake guide, but I'm not 100%.

 

[TurboBob]

The guides are no problem, they can be tweaked when the heads are off. I was planning to switch to beehive springs, so I should be good on that.

My question was more related to guide life when running over .500 lift at the valve.

There is a 210 lobe and a 214 lobe that I am considering, either would put me at .503 or so at the valve.

The car is 98% street duty, so the longevity is more important that max power.

Bob

 

[TurboBob]

I have a 218/218 in my car with 1.65 rockers and iron heads with no issues so far. The lift with the rockers comes too just under .550. I'm pretty sure the exhaust guide has just been cut down to the size of the intake guide, but I'm not 100%.

How many miles on this combination?

Bob

 

[Slow91z]

Hard to say exactly...Put the cam in about 2 years ago, before that was the same combo except stock cam.

Maybe 5000, but that's just a guess.

 

[Mike Licht]

At that lift I see no issues with guides. The 3050 210* lobe works very well and has a little more 200 duration that some of the smaller lobes. The Extreme 4X4 lobes are super agressive and may be perfect for what you want just have to watch the L/S. Let me know if you want something ground.
Mike

 

[TurboBob]

"Super Aggressive" is not really what I am looking for, I just want to utilize the advantages of the roller technology and size the cam to the engine combination without causing a lot of noise or wear issues.

The cam I have now is pretty tiny, as far as roller cams go. I want to stay on the conservative side.

The Comp literature lists the duration specs, but is missing a lot of the "aggression" details. Is a "High Energy" lobe more or less aggressive than an equivalent sized "Magnum" or an "Extreme Energy"? I can't find my "Marketing buzz-word decoder ring".



Bob

 

[TurboBob]

My current cam has been in the car since 2005 or so.

B

 

[Mike Licht]

The difference between high energy and magnum is mostly .050 duration somewhere around 220@.050 they change over. The exteme energy lobe have faster opening ramps. if you compare the .050 number to the .200 number you can see the more agressive ramps will have a larger .200 number even though the .050 number may be the same or smaller. You said "set up for more RPM", how high is "more"? 6000? 6500?
Mike

 

[TurboBob]

the new shortblock is a 3.830 stock block with steel crank, steel center caps, stock rods, and Wiseco pistons. Compression will be right about 9:1.

The heads flow decently if I can trust the flow sheet. I figure I will shift it around 5800. But its still primarily a street car.

The 210 High Energy looks promising if the extra lift won't wear the guides out.

I'm half tempted to just run the little cam, considering how fast some guys have gone on the stocker...

Bob

 

[Mike Licht]

if 5800 - 6000 is the target then the 210 based on that 3050 lobe will be good. email me some flow numbers on the heads.
Mike

 

[TurboBob]

head flow #'s

The heads were done by Mike Smith's friend many years ago.

Before I ever bolted them on, several other "experts" looked them over and "fixed them"...

As a result, none of the valve stems are the same height, pushing me into the purchase of the T&D's......

Needless to say, when I get ready to swap them, they will likely need some attention.

flow sheets attached.

Bob

 

[Mike Licht]

What turbo? same one? I have a very good head guy if you need one
Mike

 

[TurboBob]

Same turbo, cast compressor 6776 watercooled ball bearing, ported shroud "S" cover.

Thanks

B

 

[bison]

With Iron heads you will see little gain running more than .500. I'd rather have a fast ramp to .450. Ive been running a low lift version of the 212 and it has less than .500 lift with 1.65's. I havent checked but the duration is probably about 214@ .050 with the 1.65's. It will pull to 5900 with enough turbo/boost. I've ran both the comp 941 at 1.700 and the comp 26918 springs at aboun.050 from coil bind and they both worked equally well. If you are looking to run 9's you may need to rethink the springs but the above will work well into the bottom 10's. You would likely net a lot more keeping the 204 running 1.65's and getting a PTC 9.5" if you don't already have one.

 

[TurboBob]

I was thinking something similar, but didn't want something overly aggressive that would pound the seats out of these old heads...

I have a PTC 9.5" waiting for me to find time to put it in.

Bob

 

[HelloBozos]

I run the T@D 1.65's with comp cams 218..no issues GN1 irons, Car Fly's..only complant ,at idle its a little clicky, but you don't want super tight valve lash on turbo motor, you'll break something under boost..When i'm at WOT theres no clicks...heh..i use 15/50 mobile 1 racing,RJC biggie filter an oil cooler,I'm hwy set-up car for 180mph..8^)

Enjoy!

Brent aka Bozo

 

[TurboBob]

Bison:

Got any old used-up junk you want to trade....?




Bob

 

[bison]

I was thinking something similar, but didn't want something overly aggressive that would pound the seats out of these old heads...

I have a PTC 9.5" waiting for me to find time to put it in.

Bob

I've ran most of the common high energy cams. They work best with comp 885 lifters. There is little to be gained with more cam unless you will be throwing enough at it to trap over 130mph. The 218 is not a good option for iron heads unless the short block is solid. I've dynoed a couple iron headed cars with them and they all peaked after 5400 rpm even with sub 25psi and a really good coupling converter. Thats too late for a street car that won't be trapping 135 or higher. There is just no need to be that high.