Looking for a cam

[theblindchicken]

Cams have to be match with the correct compression. a hotter com on an engine with compression rated lower or even on the low side by the cam maker will just burn fuel and never perform You have to know the weight you will be running and the static compression for the cam

Currently sitting right about 9.5:1

Domed pistons, block has been decked before, 76cc heads and gonna use fel pro gaskets.

May swap heads down the line to bump up CR to 10-10.5:1, but that's a ways a way.

As she sits, truck is currently 55-5600 lbs running 35's with 4.10's. TH350&NP203 as well.

She sits about 2800 rpms at 60-65mph.

 

[TheSquareGuy]

I got a lunati voodoo for my 454 its as far as I'd push for a daily

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[theblindchicken]

I went with the

Comp Cams 12-238-2 since it's the same duration as the previous cam with a little more lift. Trying to go for a little more power without sacrificing too much efficiency of having a large loping cam.

I know it's still a best estimate, but camquest states approx 300hp / 400 tq at the crank with my setup.

Thinking in a year or two i'll bump up to 70/72cc heads to bring the compression up to 10:1. About as high as i'm looking to go for a daily.

Based on that, how big is too big for the intake runner volume?

 

[shiftpro]

Deck the block again if you need to. Might need to install the crank and one piston/rod to determine where the piston sits in relation to deck height. Zero deck for sure.

 

[gpmorgan]

Don't forget to unshroud the valves if it hasn't been done. It helps the flow greatly. With 9:5 compression a .5 lift should work pretty good. 342 gear and 2500 stall would help also. I wouldn't go over a 195 runner for that 355.

 

[Honky Kong jr]

What gear ratio are you running with the 35s?

 

[gpmorgan]

Oops. Missed that part. Those 410s you have will work pretty good.

 

[theblindchicken]

Deck the block again if you need to. Might need to install the crank and one piston/rod to determine where the piston sits in relation to deck height. Zero deck for sure.

I believe the block was decked, or maybe it was the heads.... Not 100% sure on it. Will definitely check everything out though.

Don't forget to unshroud the valves if it hasn't been done. It helps the flow greatly. With 9:5 compression a .5 lift should work pretty good. 342 gear and 2500 stall would help also. I wouldn't go over a 195 runner for that 355.

Not quite sure what you mean by "unshrouding the valves." I just had a local machine shop rebuild the heads. Sitting in the garage waiting to be masked for paint.

What gear ratio are you running with the 35s?

Running a set of 4.10's with the 35's. As far as I know, the truck has the stock converter in it. Worked just fine with the last engine rebuild. Still shifts smoother than butter.


The heads are currently mismatched since the shop couldn't locate a second 487 head that was in usable condition. Originally had a 487 and 882. Now it'll be a 487 and a 993. Both running the 1.94/1.5 valves.

 

[theblindchicken]

Future plan so far:

Replace the intake with a high flow dual plane

Replace heads with a 70-72cc 2.02/1.6 set for higher flow and a 10:1 compression.

 

[Honky Kong jr]

Are the combustion chambers the same size?

 

[theblindchicken]

Are the combustion chambers the same size?

Combustion chambers are virtually identical.

487 in the back, 993 up front.

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[Honky Kong jr]

Combustion chambers are virtually identical.

487 in the back, 993 up front.

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Ok you don't want an imbalance of compression is all I was getting at. You should be good as far as valve shrouding with them big chambers.

 

[Honky Kong jr]

Combustion chambers are virtually identical.

487 in the back, 993 up front.

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FYI you shouldn't store a crank laying on its side. Attach it to the flex plate and store it vertically.

 

[theblindchicken]

Ok you don't want an imbalance of compression is all I was getting at. You should be good as far as valve shrouding with them big chambers.

Yeah figured that's what ya were getting at. Maybe the only difference between the heads is the intake or exhaust runner. If they vary, my guess is they aren't much different.

 

[theblindchicken]

FYI you shouldn't store a crank laying on its side. Attach it to the flex plate and store it vertically.

So it doesn't get warped? Hadn't thought about that.