MasterDave

We all sure like to know if our combo is "right" and I'm no different. Here's my combo for the December project. 355 ci, 4 bolt. .030 TRW forged pistons at just under 10-1 according to Summit. My water-in-the-valve reliefs measurement shows right at 10-1 though. Weiand Stealth dual plane intake, Holly 650 DP, Sportsman II (64cc) iron heads, Dynomax ceramic coated headers (1 5/8") going into 2.5" pipes out the back thru 2.5" Dynomax superturbos. Comp. XE274H cam, alum true rollers (1.5). All balanced. The engine is on a stand in the garage waiting for instl. I'm hoping for 400hp/400tq (at the crank obviously) minimum. Thanks for your kind assistance. :cheers:

Oops, forgot the cam specs; gross lift in. 487 ex. 490. Dur at .050 230 in, 236 ex. 110 lobe sep. Hope this is enough info.


[Modified by MasterDave, 9:58 AM 11/7/2002]

Caboboy

Dave, this shows a nice torque curve! Starts out at 362# at 2000 RPM and climbs steadily to a high of 403# at 4000 rpm. At that point, it drops off gradually to 322# at 5K, then falls rapidly.

HP numbers climb steadily from 220 HP @3K, to a max of 377 @5500RPM. Sounds like a nice motor. If you or anybody else knows how I could get the screens to post, let me know. I've seen it done before, but I'm "computer challenged" shall we say :lol:

MasterDave

Thanks Caboboy, I also forgot to mention the 100 shot (for fwy on-ramps ya know)... :cool:

bcwaller

Caboboy,

You need a program that will let you take a screen shot. I have FullShot and select a region manually. This is what I got:

Graph without the bottle:


Numbers without the bottle:


Graph with a 100 shot:


Numbers with a 100 Shot (note that D2000 just ads 100 HP across the board...):


Edited to see if I could make the graphs fit without being scaled...
[Modified by bcwaller, 10:47 AM 11/8/2002]


[Modified by bcwaller, 6:35 PM 11/13/2002]

gkull

Personally I didn't like that cam. This is just my own opinion. I needed to get my vette on the road so I bought a friends short block 355 ci spare that he had pulled out. So I put my big heads and intake on it. With @10.7 c/r. Very little manifold vacuum and I had a 750 cfm Demon on it.

Right in DD2000 it clearly shows the whole problem 60 degrees of valve overlap :eek: That's about 3 times as much overlap as my Solid roller! Then you can even compare it to the LPE HR 219/219 and it's overlap is a less than Zero. I didn't have much go power below 2500 rpm so it was a good thing that I had a 3000+ rpm stall and a 4.11 rear.

MY advice is to try it. My big intake system probably caused considerably more low rpm/ off idle stumble than your setup.

74vetteman

I had that cam in a 355, and didn't like it alot either. I had a 650 dbl pumper, weiand Team G singleplane, Edelbrock rpm heads (70cc),flat top pistons, and 1.6 rr's. I thought it would make more power. It had poor vacuum and idle also.

MasterDave

gkull, can you explain the 60 degree overlap to me? I'm looking at my cam card for the XE274H-10 but I prolly don't know how to read it correctly. What should a good overlap be?

Also, and I realize cam likes/dislikes are somewhat of a preference item, but this cam (XE274H) has a power band of 1800-6200, idles at 650-700 with a definate lope and will blow the tires off at anything over 2500 rpm. It's been in my old engine std bore 350 @9.25-1 for almost a year. I've found the useable horsepower to be like DD2000 shows however, in that the power is useable at 1600 and falls off after 5500. I'm running rams horn manifolds now, so the headers should wake it up some. Overall it's a great cam IMO. I would opt for a wider lobe sep. though (like 112-113) to tone down the idle roughness some. This is actual use/seat of the pants driving experience. I have not noticed the lack of hp down low but maybe I'm used to the cam and do not know any better. I can pull away from a stop light with no problem but I have a CR Muncy and 3.70 rear. Some more opinions of this cam would be welcome. Thanks......


[Modified by MasterDave, 1:35 PM 11/8/2002]

gkull

Your 4 speed and 3.73 is just what you need to get you moving! If you have driven it and like it your in great shape. overlap is the amount of time in degrees when both the intake and exhaust valves are open. So it causes two problems reversion into the intake and raw gas going out the exhaust ports.

That's why it would have a rowdy sounding idle.