How good will L-29 heads be over Close Chambered BBC heads

[1980RS]

I was running a low compression (7.9 comp) 461 BBC engine for some testing with heads the last few years. The first set were a set of 236 peanut port heads that had some mild porting and stock valve sizes on them. Car ran high 11's, then I switched to a set of 215 closed chambered heads with 2.19 and 1.88 valves and the only work was some slight bowl clean up. The car only picked up maybe a couple of tenths in good air but nothing in the MPH area which meant the little PP heads were pretty good, really thought the CC heads would have made more of a difference. Now I have some L-29's I would like to try, mostly cleanup and rocker stud hump removal. So my question is will the L-29 heads be any better than the PP 236 heads? Thoughts?

[Schurkey]

How much of the "ski jump" are you carving out?

The L29 heads are likely to be very durable--they've got hardened seat inserts on intake and exhaust. The casting is quite nice, minimal flash, etc., and the exhaust port is "said" to be good; although I haven't confirmed that. The exhaust valve guide boss looks pretty damn blunt to me.

The intake port and ski-jump is more like the SBC swirl-port junk than the SBC Vortec head.

The combustion chamber "looks" nice, and is said to be a decent "fast-burn" design.

When I had 'em on my boat, I could get to about 5100--5200 RPM fairly quickly, and then NOTHING above that. This was a ~100 rpm increase from the used peanut-port heads that came with the engine, using the same valve sizes.

Beware the INTAKE valve guide boss where it intersects with the valve spring pocket. Two guides on each of my heads had to have some grinding at the radius of the spring pocket-to-guide before the valve rotator eliminator shims would seat flat on the casting. Exhaust guides don't have that problem, as they're pressed-in.

There was an article on the L29 heads in one of the hot-roddy magazines; but the testing was so poorly done that the article didn't really make sense. Their conclusion was that there was some minor improvement from stock, un-ported "Peanut port" heads in both horsepower and torque. They didn't say if it was from the compression bump, the chamber design, or the ski-jump swirl port.

[1980RS]

As the one cyl head porter here in town said "get rid of the swirl hump, you're racing not driving around town", he must know what he's doing as he has made some of the best flowing LS heads and take the swirl ramps out of them and his head perform very well. My 236 pp head would pull very easy to 6K but after that they would stall and running the engine up higher would just hurt ET.

[mag2555]

They where designed for a high level of Intake swirl and low timing needs , but the swirl cuts into power that they could make otherwise.
I would sooner go back to bowl ported PP heads fitted with a 2.19" valve with chamber opened up for it then to apply that same amount of work to the L29 heads.

At least the PP head set up as above can make 525 to 550 hp depending on the compression on a 460 cid motor.

[tt 383]

Wondering if anyone has touched a set of the EQ Vortecs? Usually their castings are thicker/meatier and more favorable for porting. 246cc 2.06x1.72 100cc head
https://2u7bve3d8yjttiswb3gnx3uo-wpengi ... CH454C.pdf

If you search good, you can find a sectioned L29 head was maybe Yellowbullet or team Chevelle, and I believe a half hearted diy bowl blend thread on Team Chevelle. From memory the bowls are thin and the swirl ramp has water under it.

[tt 383]

Sorry my mistake, sectioned head here...
https://www.hotrodders.com/forum/bbc-l2 ... ics/171714

Would love to see a good known head porter do a set with a 2.125 intake.