Would a solid cam with 232@.050 duration, 264 adv.(at.020) with .482 Lift be too much for a 355 with World S/R Heads(1.94/1.5) that will be moderatly ported(hopefully will flow in the 220/175@.500 range). Compression can be 9.4-9.8 depending on what head gasket I use, what is the ideal compression ratio? This cam needs to also work good crusing in 5th at 1,900rpms.

Also, do you guys think a single pattern would work best with this combo or a dual pattern with the above profile on the intake and 238@.050 270 adv. with .486 Lift on exhaust?

I'm sick of low 14s with the 203/212@.050 hyd. economy cam in there now.

IMO It should work nice esp. on a 108-110 LSA. My 385 with a 240 @ .05 cruises @ 1900 just fine.

Jim

My dad's engine is a 355 with 2.02 S/R heads, 10.25:1 with the Comp Mag 282 solid, VERY streetable. Car ran 12.72 in 100 degree, sticky air and jetted too rich. Your set up should be even better on the street.

I have a 355 with a set of S/R's with 202/160 valves that have been pocket ported.
I have seen a few air flow sheets on S/R heads,not mine though.
I would use a slightly smaller Dual Pattern Solid cam with 110-108 LSA.Something with 224-226 intake and around 232+ exhaust duration at .050.

I use to run a HYD ISKY 280 Megga cam 280 232 485 108.It worked well with 10.25:1 but it wasn't the happiest at that low of an RPM.I swapped to a Cam Dynamics HYD 278 221 467 110 and it was much better on the low end.

I would tend to agree with Thrasher,you should reduce the intake dur @ .05 a little from 232 to 224-226 ish deg @ .05 and stay with a 112 or maybe 110 L/S angle.

If you had a 383 stroker with more cubes i would stay with your cam but with 232 deg dur @ .05 and 355 cubes it would be a little soggy on the bottom. The stock GM 350/350hp cam had 224 int dur @ .05 and was a little soggy on the bottom in the 350's. But, that was a hyd cam and not a solid cam like your going to run which can handle a little more intake dur timing than a similarly spec'd hyd cam. If bottom end torque is not important to you then stay with your cam.

I would stay with a dual patt cam with more dur on the exauhst (approx 6-10 deg more ex dur @ .05 than on the intake side) side unless your exauhst has very low back pressure almost straight through which most street cars don't have. The single patt cams are cheaper to grind and buy but they suffer h/p loss on the mid to upper end because they can't get the exauhst out as well as a dual patt cam can due to the shorter exahust timing (Duration).

Give Harold (Master/Expert cam designer/grinder) at Lunati cams a call and he can set you up with a good solid lifter cam for your application/needs.

Scott

I heard solid cams typically act 6-8 degrees smaller....so a 232 cam would act more like a 225 hydraulic, which I didn't think would hurt low end too bad espically since the solid helps low end torque.

I also have seen flow numbers of these heads ported and the I/E ratio is always in the 75-80% range which I thought would like a single pattern cam. Once ported the exhaust side flows real good(175+) and the intake can be done to go in the 220-230 range even with the smaller valves.

I know stock the ehxaust port sucks and would like a dual pattern but ported would I really need a dual pattern?

I'm also looking at the xs268(solid version of xe268)...its 230/236@.050 with .488/.501 Lift, think that would be a better match?

AllGoNoShow'

If you are fairly confident that the I/E ratio is going to be around 75-80% then go ahead and get a single pattern cam. At most get a 4% split 232/236 @.050.

As you correctly state a solid cam will act approximately 8 degrees smaller (@.050) than their hydraulic counterparts. Personally I think your cam choice is right on and should produce very good results. The seat timing on the cam is very short and should make for a nice street ride.

I may just shell out the cash and get the heads flow tested after I port them so I know for sure.

If I get a little scared of overcamming it I could always go with the xe262 solid...its a 224/230@.05.

Remember that it is only a 264 advertised duration solid cam so is indeed small.

Should be almost perfect for you, imho!!!

pdq67

I think the cam is in the ball park. It will probably have a fairly choppy idle. As for the compression ratio, you might want to run your combo through the DCR calculations to see what its DCR is. From what I understand the new comp cams produce alot of cylinder pressure and the milder ones are made to work with a lower compression ratio.

Thanks for the tips guys!

Now for a 2nd part to this question. With a small solid in the 225-235@.050 range do you think it is absolutly necessary to run dual springs? The cam companys want dual springs but if I find singel 1.250 springs with the same or very similiar pressures do you think it will be okay? I've heard of one person running the xs268 with 1.250 springs with similiar pressures to the duals comp reccomends and it worked out for him I just want some more reassurance!

I just dont want to shell oput the cash to machine the spring pockets bigger and run expensiver dual springs and have to get new retaniers also...i'm on a college budget here!

graemlins/clonk.gif Is it too late to change my answer without looking like an a$$ graemlins/waving.gif

As these guys pointed out you are dealing with a solid.They are right about the solid acting smaller on the low end.Don't know what I was thinking.
232-234 on the intake should work well.
I would still stick with a dual pattern profile with 110 LSA.

When I bought my UD 267/271 (239/243 @.050), I asked the same question, since I wanted to use the K-Motion K-750 springs. I was told that they would work fine. Seat pressure (I am going on memory) is 135 and about 340 open.

A long time ago I saw an article where different springs were tested. without going into it too much, the conclusion was: That the lightest spring, that could produce the pressure needed to control the valve, would provide the most rpm and stability.

http://www.competitionproducts.com/page25.html

Take a look at the Z28 spring I`ve had good luck with these on hyd. cams & the price is right too.

Jim

Originally posted by rubeng442:
When I bought my UD 267/271 (239/243 @.050), I asked the same question, since I wanted to use the K-Motion K-750 springs. I was told that they would work fine. Seat pressure (I am going on memory) is 135 and about 340 open.

Is that solid cam? UDHarold said single 1.25" springs would work fine with the small solids? Thanks for the reply, that would be great if I could use a single spring with a solid, I mgith have to look into these UD-Lunati cams.

Yeah, it's a solid. I bought my cam through one of his dealers, Greg Godon. I told him my plans, he said he did not forsee a problem, but that he was going to check with UD (I am not sure if wether with Harold or Tim) and then tell me what thei recommended. When he got back with me, he said that it should work with no problems, just to make sure and check my springs after a year or so.

I agree with 77 cruiser. Ran/raced the Z-28 springs in a 355 for 5 years with a .465 -.230 Sig cam. 400+ passes & drove it on the street 2-3 days wk (ran 12.30's). Motor is back stk now but still running the same springs. Lot to be said for "keep it simple". You don't need any higher spring rate than the Z-28 for the size cam you mention.

Actually I somewhat disagree with that statement. Just about all cam companies recommend between 130 to 140 lbs on the seat and about 320 to 340 open pressure for a solid cam. The more agressive the cam the more spring it needs, regardless of how "mild" its seat duration may seem. The cam AllGoNoShow describes has very fast ramps, the z-28 spring with its 105 lbs on the seat (it maybe even less) will not be able to control the valves at high rpm, at least not with a cam as agressive as this one.

AllGoNoShow,just for the heck of it you might check out speedwaymotors.com.they have a high-lift spring kit for 59.95.it features .600 max lift springs with 125lbs.seat pressure,365lbs.open, and fits stock diameter seats.i'm not sure how these pressures will affect your cam in a daily driver,but its something to chew on.