Another aluminum head question.

[351FUN]

You're thinking of 351FUN.


Thanks for that. SO true. Folks end up with a "lopey cam" as a side-effect of high-rpm tuning, or because they can't tune properly, not because lope is desirable in itself.

"Lope" is misfire. Misfire is a loss of power and fuel economy, coupled to an increase of catalyst-killing HC emissions.

Yup, that was me. Also I did want lope with my F250, but that was entirely because I like the sound and the truck is 100% play toy. It's also pretty gutless until you get it spinning up pretty good.

EBL? What's that?

Magic doodle that lets you tune the ecm yourself.

 

[L31MaxExpress]

If I end up yanking the engine from WCJr for Roscoe, those AFRs are the heads I'm aiming for when I build another motor. Yes, the heads are cast in China, but AFR does the porting and final machine work.

They're set up for lighter 8mm valve stems like the LS uses instead of the older 11/32" valve stems (8.7mm). They use pushrod guides instead of self-aligning rockers. The intake manifold opening needs to be checked against whatever intake you're using, but that's neither an insurmountable nor even expensive problem. Putting a TBI on top of Vortec heads is a simple matter of a Vortec 4-barrel intake manifold and a TBI adapter.

Don't even bother with a flat-tappet hydraulic cam. Seriously. Make the jump now. Even swapping to a Vortec roller cam is an upgrade from the TBI cam.
LO5 cam
.382" / .401" lift
166 / 175 duration @ .050"
109° LSA

L31 cam
.414" / .428" lift
191 / 196 duration @ .050"
111° LSA

Except the Vortec cam is smaller than the TBI cam. Those specs are flat wrong for the L05.
I have even gone so far as degreeing a couple 10-15 years ago before I pulled them out. The TBI cam is the same old 929' cam that was in almost all the other small blocks. In the TBI truck parts diagrams it shares the same part number as the LU3 305 crossfire cam. GM heritage had the specs on it as 194/203 @ 0.050 and 0.390/0.410 lift. EVERY OE replacement cam also has the sames specs like the CS-274 and CCS-2.

 

[Vikingdude]

If I end up yanking the engine from WCJr for Roscoe, those AFRs are the heads I'm aiming for when I build another motor. Yes, the heads are cast in China, but AFR does the porting and final machine work.

No porting is done on the enforcer series. They are an as-cast head. Machine work is all done in China, these are likely the Quantico cylinder head sold by at least a dozen other vendors. Final assembly is all that is done by AFR. Putting the valves, shims, springs and keepers. Springs are a PAC pn, nobody at AFR can tell me what valves they use.

Same heads are available with cheaper parts from Skip White Performance, or with more expensive parts from CNC Motorsports. CNC Motorsports will also CNC port them for an additional fee, but I think they only have the angle plug versions at this time. They were also sold bare as DNA motoring. The AFRs are the only ones with the 8mm valve stems, which is worth a very small bump in flow numbers.

 

[Erik the Awful]

these are likely the Quantico cylinder head sold by at least a dozen other vendors.

The AFRs are the only ones with the 8mm valve stems, which is worth a very small bump in flow numbers.

When they came out AFR stated the finishing was done here in the US by them. If I remember right, the article I read said they do the 3-angle valve job, they install the valve guides, and they do some cleanup work. I'm trying to find the article, and I'll post a link if I do.

8mm valves are worth a small bump in flow, but they're also significantly lighter.

I did find this statement: "These heads are perimeter bolt only, no option for center bolt. The heads have the 86' and older bolt pattern and the Vortec bolt pattern, but only the 86' and older intakes will work due to the port dimensions. The Vortec is a taller port and won't match."

 

[Pro439]

So like what is mentioned the late vortec heads really flow at stock rpm range but the intake ports are higher. If the cylinder head has the dual bolt pattern an old style intake will bolt up no problem but you should ask the manufacturer if an old style intake will work for port alignment. The 195 cc intake runner is really pushing the head to have very good velocity at lower rpm’s. GM and dart are as far as I know the only 2 making a iron vortec dual bolt pattern head and I think you can only get a single plane intake now for these heads as most people are going efi with them. Because the ls engine has become more of a go to which to me is not a gm engine but a global engine aftermarket companies have all but stopped making stuff for the vortec engine. The biggest downside to that head is the deck is thin and tends to crack and if you run more than a stock cam you will have to cut the guides for clearance and while you’re doing that you might as well have a set of guide plates and screw in studs put in. The other thing to note is that you don’t need to use a cam that accepts the retaining plate but you will have to use a cam button if you go that way just like you did with the non cam retaining plate engine. The other thing gm did on the late 90’s engine was put a cam sensor in the bottom of the timing cover so you can’t fit a double roller chain. FAST makes a crank trigger kit that you can use the cam sensor from the engine for cam position. And I highly recommend a hydraulic roller cam as you will be able to run more.050 duration and more lift and still have a smooth idle and good vacuum without having to regear or use a stall converter. I put small port bowtie heads on my engine with a ported and filled stock 98 intake and for $400 I had the computer reprogrammed by Wester’s Garage. I hope this information helps as you can find any option you want on the web these days

 

[PlayingWithTBI]

You're thinking of 351FUN.

EBL? What's that?

Yup, that was me

OOOPS! My bad, eating lunch, watching NASCAR and surfing this forum, musta been too much for this feeble mind

Anyway, FYI, this is the EBL (Embedded Lockers) Flash-II
www.dynamicefi.com/EBL_Flash.php

 

[Vikingdude]

I sent AFR a bunch of emails that were rever replied to, but I did manage to get someone on the phone before Christmas. They told me the 3 angle valve job was performed "overseas". They would not say China, but we all know that's where it's done. If you watch Eric Weingarteners YouTube channel he has a number of videos dedicated to these heads. He complains the valve job isn't great, and also complains about how soft the seats are when he redoes them. "Smearing", or material re-imbedding itself as he tried to machine them is an issue for him.

I sound like I'm really against these heads in all my comments, and let me clear up that I am not. I came really close to buying a pair. The value on them is fantastic. I just think a lot of folks are talking themselves into believing they are something they aren't. They use as little us labour as possible to keep the cost as low as possible.

 

[DeCaff2007]

These replies are all good reads, but NONE of them answer my question.

Oh, and I'm keeping the stock cam. It's already ordered and the rest of the parts for my block have shipped. That, and the fact that I have brand new valve springs (for the stock cam) is another plus. So this means whichever heads I go with, I only have to swap out the springs, since it seems most aftermarket heads come pre-built.

I

 

[PlayingWithTBI]

So this means whichever heads I go with, I only have to swap out the springs, since it seems most aftermarket heads come pre-built.

Why swap the springs when you're going to stay with the peanut cam? Unless you're gonna spin over 5K or have a cam with more lift than the heads say they can handle, don't bother.

 

[DeCaff2007]

Why swap the springs when you're going to stay with the peanut cam? Unless you're gonna spin over 5K or have a cam with more lift than the heads say they can handle, don't bother.

Then maybe I'm confused about the whole subject. It was my assumption that I'd have to match the cam to the springs (or vice versa) on whichever heads I do get.

I'm also assuming that my advantages here, over stock heads, would be weight reduction and better air flow.

I guess my brain isn't seeing the bigger picture here. Please, enlighten me.