Cam/Heads questions
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
For the OEM heads the following works very well:
.510/.510
221/235
108 LSA
Very broad powerband. Distinct idle note. OEM heads need a split pattern camshaft. Single pattern stuff will give up some power.
.510/.510
221/235
108 LSA
Very broad powerband. Distinct idle note. OEM heads need a split pattern camshaft. Single pattern stuff will give up some power.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Who makes this cam. Seat to seat duration? Sounds good. what is the overlap in degrees? It looks slightly biggish for 9.0 CR and decent low end torque. But then it is flat tappet not roller.
Last edited by REELAV8R; Aug 9, 2016 at 03:40 PM.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
I'm glad you responded to this thread Straub. Who do you figure is still a decent flat tappet manufacturer? I hear good things about isky's flat tappets, but have no personal experience with them.
How much lift of what duration (intensity) you figure a guy can get away with without significantly increasing his chances of wiping a lobe with the current flat tappet cams?
.510 is good lift and Isky makes some with that in the 264-270 duration range. In your experience is that still a reasonable risk for those low duration's from Isky?
How much lift of what duration (intensity) you figure a guy can get away with without significantly increasing his chances of wiping a lobe with the current flat tappet cams?
.510 is good lift and Isky makes some with that in the 264-270 duration range. In your experience is that still a reasonable risk for those low duration's from Isky?
Drifting
Joined: Mar 2006
Posts: 1,263
Likes: 188
From: Wabasha Mn
The Isky Z20 cam is the solid lifter cam I am running in my carbed 84 C4. Block is stock 84 with factory forged pistions, Summit/Dart 152123 large valve, 72cc, cast iron heads. I figure I am probably at 9.0 c r or so. Z20 has 228-228@050, 450 lift 108 lsa. Lots of low and mid range and I get about 14" of vacuum at 750 rpm. Car has 3.07 rear and 700R4. Has a lope at 600 rpm in gear. Nice cam.
Melting Slicks
Joined: Sep 2010
Posts: 3,315
Likes: 697
Buy the best heads you can afford and then chose a cam to match. With aluminum heads you can run a bit higher CR with out pinging.
I've used AFR's a couple of projects with great results.
I would do the heads first. Good springs and push rods. Maybe roller rockers.
Then if so inclined the cam.
I've used AFR's a couple of projects with great results.
I would do the heads first. Good springs and push rods. Maybe roller rockers.
Then if so inclined the cam.
Thread Starter
Pro
Joined: May 2006
Posts: 595
Likes: 84
From: Colonial Beach Virginia
I am stuck with the 041 heads for now. What would it do with just the heads and 1.6-1 roller rockers? Any appreciable gain by going with the larger ratio rockers? Then do the cam later down the road.....
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
If you can't afford good parts then you should focus on tuning and TLC on a 20k mi C3. All tuning will cost you is patience. BTW a '73 is a pretty cool year I think. I guess what I'm saying is if you can't afford go fast parts now keep your car in good running condition while you source out better heads and cam.
Good luck.
Last edited by cardo0; Aug 9, 2016 at 11:47 PM.
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Thread Starter
Pro
Joined: May 2006
Posts: 595
Likes: 84
From: Colonial Beach Virginia
Sorry I don't mean to flame you but swapping heads on motor w/only 20k mi for a little more compression and a little more lift doesn't seem justified. You have a good running car now that will run well for years and chance of wiping a cam while adjusting the vales for 1.6 rockers is pretty high if you haven't done that before. Did you know you need to open the p-rod slots for 1.6 rockers?
If you can't afford good parts then you should focus on tuning and TLC on a 20k mi C3. All tuning will cost you is patience. BTW a '73 is a pretty cool year I think. I guess what I'm saying is if you can't afford go fast parts now keep your car in good running condition while you source out better heads and cam.
Good luck.
If you can't afford good parts then you should focus on tuning and TLC on a 20k mi C3. All tuning will cost you is patience. BTW a '73 is a pretty cool year I think. I guess what I'm saying is if you can't afford go fast parts now keep your car in good running condition while you source out better heads and cam.
Good luck.
Thanks. Good input. It is tuned about as much as it can right now and still have stock heads/cam. Just looking to tweak it a bit more without breaking the bank and going all out. Is the money there do go all out? Yes. Do I want to (or can justify) spending it on a perfect running Vette right now? That is what I am trying to determine. That is why I was trying to stick with vintage go-fast parts that I mostly already have and going old-school. I like the idea of the 041 heads and solid cam more for the sound, looks and the nostalgia. Make sense?
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
I'm glad you responded to this thread Straub. Who do you figure is still a decent flat tappet manufacturer? I hear good things about isky's flat tappets, but have no personal experience with them.
How much lift of what duration (intensity) you figure a guy can get away with without significantly increasing his chances of wiping a lobe with the current flat tappet cams?
.510 is good lift and Isky makes some with that in the 264-270 duration range. In your experience is that still a reasonable risk for those low duration's from Isky?
How much lift of what duration (intensity) you figure a guy can get away with without significantly increasing his chances of wiping a lobe with the current flat tappet cams?
.510 is good lift and Isky makes some with that in the 264-270 duration range. In your experience is that still a reasonable risk for those low duration's from Isky?
Then you have the regulations on oil. I can see in the next 4 to 5 years the oils for flat tappet engines will be $15 a qt.
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
Be sure the elongate the pushrod holes in the castings before you bolt them on. You have to do this for pushrod clearance when using higher ratios.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Thanks. Good input. It is tuned about as much as it can right now and still have stock heads/cam. Just looking to tweak it a bit more without breaking the bank and going all out. Is the money there do go all out? Yes. Do I want to (or can justify) spending it on a perfect running Vette right now? That is what I am trying to determine. That is why I was trying to stick with vintage go-fast parts that I mostly already have and going old-school. I like the idea of the 041 heads and solid cam more for the sound, looks and the nostalgia. Make sense?
Ok u have the cash but want to tinker w/upgrades. Yea that makes sense but there is mountain of info on sbc buildups u can use for help with what u want to do. Well D. Vizard had a mule motor L48 (dyno mule for testing) that he optimized w/the stock 929 cam and 041 heads. With a decked block (for quench) 4 degree advanced cam and pocket ported 041 heads he got 300hp and a flat torque curve from 2000rpm. U can read the build in his "How to ... sbc on a Budget" book. And another good reference is an HP book by Chevy HP on sbc Engine Buildups - less than $10 on Amazon. The Chevy HP book covers the "Goodwrench Quest" series on the Goodwrench 350" 260hp crate motor build ups all way to 471hp w/a blower.
Hope this helps and good luck.