Who is best ? for a street performance car.
Advantages and disadvantages.........
I heard a lot but what is true????

John Lingenfelter built a roller-cam 496 with spectacular results, using (ported) stock casting oval ports and big valves.

You want the velocity in your heads to be high. the ovalports are huge anyway and rektports are to big for almost any BB of any size under 500 cui, if you dont have a ultralight car and revving it to the sky.

Lingefelter use onle 049 and 781 ovalports. no rektport at all. ports them to flow better than standard rektports but have velocity to move air at low wngine speeds.

Hope racer1320 will back up my teories whats best for a heavy car(ie chevelle).

Godsend is right on the money....
Non-truck oval port heads have huge ports....you can almost stick your fist in the damn things.

For a street motor, oval ports have excellent throttle response and have no problem making power into the 6000 range.



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"A days pay on the wild side"
'67 Chevelle 396/Th400/4.10

what about peanut-ports? what's the difference? and what's wrong with truck heads? are you telling me my big block is gonna suck?!

It will not suck, it outperformes a lot of high-hp cars with it torque. Bild your engine to rev 5500 rpm, stall 2000, add a performer intake. Not Rpm. Ask for the right grind at your camshaft manufacturer. around 3.5 rearend and youll fry your tires as long you want and eat Boss mustang for lunch http://www.chevelles.com/forum/smile.gif

Yeah, no doubt my L88 sucks with the stock rect ports, Think it only makes about 200 HP or so http://www.chevelles.com/forum/tongue.gif.

Serioulsy, I cant hardly tell when the cam runs out at 6500 because the heads are just starting to work. I think the 2nd Gen L88 castings I use would be nice on a 540.

Or the 427 would work great in a NASCAR type ride where you're staying in the 5500-7500 range all the time.

But if you're building one from scratch, under 500 ci and under 6500rpm, ovals are the way to go. Heck some of the new aftermarket oval heads flow nearly the same as the factory rects with more velocity.

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G. Chaas
Gold #62/ACES
67 SS396/(427L88) (http://www.chevelles.com/showroom/chaas1.jpg)

Maybe youll eat L88:s for dinner to http://www.chevelles.com/forum/smile.gif

No offence Gene

Well Stefan, I'll tell ya, you put racers motor in my 3.55 geared Chevelle and yes, it would no doubt. The L88 might out HP a comparable oval port, but the oval would be quicker in a 3800 sled especially with street gears.

I can tell the L88 would be real fine in a light little Willys or Anglia with 5.13's!

( remember the L88 is a nostaglia thing. This is the same mill I built 20 years ago as a kid - so it stays - period and its plenty fast n fun for me.)

I now why you keeping it, the only reason why i use a roller and a dominator and calles her by the name LS7. Itīs so nice revving a Large cube engine http://www.chevelles.com/forum/smile.gif

Roland, there isn't a BB out there in a "real street" car(read heavy, turning 6500 RPM max and with moderate compression) that won't run quicker and faster with oval port heads. Even better if they're closed chamber and stay away from aluminum. All you need is good valve job with 2.19 /1.88 valves, bowl job and gasket match.

However when it comes to maximizing performance it's more about the combination and for these heads to realize their full potential you must run a dual plane and small tube headers.

If you need any additional info on this topic do a search on my user name.

racer, I was on the phone with my machinist recently, trying to arrange a good time to drop a lot of parts off, and I asked him about the big valves. He said unless it's a performance block, with the cylnders notched on top for the bigger valves, you may actually LOSE power by going to 2.19/1.88 valves. I wasn't really phased by that, because my block is a 66, and all 66s were so notched, but is that really true? I'm just wondering here? It ALMOST makes sense... but what if you zero deck the block? Am I missing something????

Stefan, one more thing my friend 509 just reminded me of, the L88 did produce 560 HP. All "unmatched" and all. And I know, if I geared my car up to 4.30 + and ran an auto, I would eat 502s for lunch. Rather easily in fact. And thats not bravado, heck the motor can pace with them right now. Let it rev up to where those heads really flow, forget it. Question can 570 HP outrun 502 HP? Answer: quite so, if the gearing is set up to use the high rpm powerband.

So 6000 or less ovals, 6500 or more rects is my thought.

I think my combination is very well balanced, big 850 ( for a 427 anyway), 2" primary tubes, rect ports, 3.5" heapipe. It really rips well. However, the physical characterisitcs of it lends itself better to a light car, with much stall and gear. It would be an easy 10 sec ride in that config.( I only wish I had a nice solid roller in there!). In a heavy car with no gear and a 4 speed, its a 12 sec ride.

[This message has been edited by Gene Chas (edited 07-13-2000).]

so about the bigger valves...i was planning on running 2.19/1.88 valves in my '79 peanuts, but now you have me wondering-can i? what about sticking with 2.06/1.88; will i still have to notch?

lev, you want to use the 2.19 / 1.88 valves. More important is that the chambers are laid back to unshroud the valves. As for the block there should be no problem however during the checking procedure if a interference is discovered the the block can be relieved at the top of the cylinders. Also a valuable lesson should be learned by all with the experience that Mr.D is going thru right now. You need to thoughly checkout your machinist / "engine builder". Many guys out there only assemble parts and don't know the first thing about building a motor for a performance application. Make sure this guy's core business is not rebuilt motors for daily drivers. Also get names and numbers of customers that he built race motors for and talk to him up front about about his warranty and deposit / payments. Take a tour of his shop and look over his operation, equipment and employees. Now all this doesn't guarantee anything but at least you'll be informed up front to the type of work he does and how / if he stands behind it. Only then can you make an informed decision.

Kody, I would'nt waste my time with the peanut port heads. Your $ would be best spent on the larger ovals and depending on the piston your using closed chamber at that.



[This message has been edited by racer1320 (edited 07-14-2000).]

Thanks, racer. I've actually been to see my machinist a few times, have seen his shop, and he built one of my friends a WICKED 455 for a 79 Firebird. He works alone, and does mostly performance motors. He built a 10 second non-street 427 for another kid in town. He seems like a very knowledgable guy. Real calm and collected, and nothing he has said yet made me think he's an idiot. So I'll be going with him to do the work. And he has a passion for Eagle rods. I don't know why.

Now you've got my attention. While I don't use Eagle rods myself I know several folks that have had problems. In addition I believe the I-beam style are far superior to the H-beam style. For the difference in money I'd go with Crower Sportsman rods which are under $600. Anything Crower is top notch stuff. Eagle cranks however are fine. Cranks generally don't break it's the rods that do.

[This message has been edited by racer1320 (edited 07-14-2000).]

I have ovals in my 486 ci. w/ porting of unknown origin or quality. The motor made 632 hp and around 600 lbs of tq. on the dyno.

racer1320,

I was going to use the original rods anyway, because they are in excellent shape. No use spending money on something you already have. I was just gonna have them magnafluxed and probably glass-beaded. So should I stay away from this guy? My friend is very happy with his motor, and recommended the guy.

I'm not in a position to say either way. But just cause your friend is happy doesn't mean you will be. Take nothing for granted and ask the questions. Better to know now than latter if there is a problem. Get those references from guys other than your friend and preferably from some serious racers whose motor's he has done.

Have those rods mangafluxed. It's not what you can see but what you can't and that will determine if you can reuse them or not.

[This message has been edited by racer1320 (edited 07-14-2000).]

racer, you are again the voice of reason. Are you sure you don't wanna just build that motor for me http://www.chevelles.com/forum/wink.gif

r1320,

What kinds of problems exactly were these people having with eagle rods? Were they installed properly?

My engine builder has used them in many engines, and has not had a failure that can be attributed to the rods themselves. In his opinion they are of equal quality to the Manleys. And he has used them in street engines through blown alcohol.

Ryan

[This message has been edited by 505_Malibu (edited 07-14-2000).]

Ryan, rod failure in both big and small block engines. These were professionally built race motors that see action every week. As for comparing them to Manley's well they too aren't of the same quality as Crower.

Guys,

Just a quick note on the Eagle rods. They used to make their own fasteners and did have some failure due to the fasteners. They now use ARP fasteners exclusively and the problems seems to be taken care of. I know many, many people that run them without problems. I have a set myself and three close friends do as well. All see about 5000 street miles a year and are regularly tortured at the track. All are high RPM small blocks. No problems. I plan to put 700 HP to my set, so I'll see what they are made of for sure. However, the best rod available are Oliver, but they will set you back about $1100 for a set.

Racer1320 how recently have you heard of problems with the Eagles?

Jason Gore
AKA DragRacer
jgchevelle@aol.com

Jason, last year with these failures and I too heard that they switched to ARP. However this is Eagle's spin on why they had the problem. Also, this still doesn't address the fact that I- beam rods are stronger than H-beam rods. I will agree that oliver rods are very good, the best however is a matter of personal experience and opinion.

I have to jump in on this which is stronger debate H beam or I beam. I beam rod will take higher compresive loads and H beams will take high RPM. Due to the fact that they have less whiping at high RPM. RPM more than power is what kills rods so if your building a high RPM motor you want H beam rods.

So when I build my 4.5" bore , 3.76 stroke "modern L88" ( on a bowtie block ) I should use rect port heads and H beams. OK.

Guys,

I'll add a few comments on the H-Beam vs. I-beam. Snow427 is exactly correct. An I-beam cross section can take more load in compression and bending based on geometry given equal areas. However, the only time this would really come into play is if you hydraulic a cylinder, in which case either is going to bend. Rods simply(usually) don't break due to compressive loads. #1 is the fasteners. That's the first place they will usually give up. Using top quality bolts from a manufacturer like ARP solves this problem. The next location failure typically occurs is at the pin end(just below the pin) of the rod. This happens as the piston approaches TDC, then stops, and then is yanked in the opposite direction. So as Snow427 said it is RPM that almost always kills rods. The rods are usually OK as compressive force is applied to the piston(compression), but if a valve floats or hangs open for some reason and there is no force to slow the piston/rod down it greatly increases the stress on the rod and is typically when a failure will occur. Burn outs at very high RPM also eats rods for lunch. So what it boils down to if the same fasteners are used and the same material is used, whichever rod has the greatest cross-sectional area at the pin end will have a better chance of survival at elevated RPM's. It's my opinion that on moderately powered naturally aspirated motors(500-600 HP SBC/700-800 BBC) you can not beat the Eagle rods for the price. On boat loads of N2O an aluminum rod helps the bearings and crank to survive by absorbing some of the load. Just my $.02.

Jason Gore
AKA DragRacer
jgchevelle@aol.com

Well said Dragracer! I have heard that it is RPM and valvefloat that kill rods more than anything else.

Ryan

Jason, while I agree with most of your comments I qestion your logic and recomendation of Eagle Rods. Eagle and a number of other rods like Scat are manufacured offshore in the same plant and while they advertise their rods are made of the same 4340 material as their competitors their metalurgy is questionable and their finishing is suspect at best. This is the same company that was manufacturing their own rod bolts which failed.

Clearly these rods are no comparision to a quality component such as Crower, Oliver and Carrillo. BTW, it was Fred Carrillo that first produced/marketed an H-beam rod and in fairness to this design Carrillo rods are considered to be the best rods on the planet. However, Crower and Oliver's entire line of connecting rods is of the I-beam design. Knowing a "little" about steel and having read a number of papers on steel members of I-beam design and it's reaction to compressive loads, shear and tension; I still stand by my statement.

I will agree a "budget" rod of this quality can be used in a moderately powered, low RPM buildup but not a 500 - 600 HP small block and certainly not in a 700 - 800 HP big block.

Someone building a 700 - 800HP BBC is going to spend $10,000+ and doesn't think twice about buying a roller setup, good heads and carb. Then why would you trust your motor with a $70 part (rod) of questionable quality that's going to see 7500 RPM when a far superior and proven rod can be had for pennies more.



[This message has been edited by racer1320 (edited 07-15-2000).]

r1320,

Send me a set of Carillo's and a set of your Crowers and I'll have my friend (metallurgical engineer) cut them up and compare their metallurgy to my Eagles...
http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif http://www.chevelles.com/forum/biggrin.gif

I think we're splitting hairs here - stock rods have been known to live at high horsepower levels if properly prepared. Aftermarket 4340 rods, regardless of rumors about their inferior metallurgy, will survive much higher power levels, and any rod will die under certain conditions.

Everybody knows a friend of a friend who's killed a set of manufacter X's rods, but he forgets to mention the missed shift at 9000 RPM! http://www.chevelles.com/forum/biggrin.gif

What were we talking about? Rect vs Oval heads?? http://www.chevelles.com/forum/wink.gif



[This message has been edited by 505_Malibu (edited 07-16-2000).]

Ryan, the difference in metalurgy is no myth. They don't comply with SAE and ASTM standards just to name a few. Why do you think they're made in China? Because they have better manufacturing facilities, materials and skilled labor.

You and I both know that's not the case but rather as usual to produce an inferior product that cost a fraction of what the benchmark part does so as to reap a higher profit margin. Yet they don't pass the savings on to you the consumer but rather market them in the same price range as the quality component.

These folks I spoke of are skilled drivers and racers and not novices. As a matter of fact two of these racers run in Super Pro were electronics are plentiful and they have every gadget there is including multiple RPM limiters and electric shifters.

I certainly hope you never have a problem cause as you also know the result is catastrophe. Clearly this type of result is not a chance most of us are willing to take or have the budget to absorb.

The purpose of my response to this post and all others is to share my knowledge and experiences both good and bad, so that "you" the members of Team Chevelle can be better informed and have another outlet other than the magazines claims and endorsements, to a products compatability, reliability and performance.



[This message has been edited by racer1320 (edited 07-16-2000).]

Whats better, a set of crower bb sportsman rods or set of eagle bb H beams? My only problem with eagle rods is considering some poor chinese dude working for 1/10 of a cent a day or worse some dude in a chinese prison for littering, serving a 300 year sentence manufacturing connecting rods.

When i bought my rods i talked to carillo. and they said that their rods and manleys H-beam are a long way ahead of the eagles. They have alot of people that bought carillo rods from engine shops and find out that there was only carillo bolts. The only way to make sure its carillo is to look at their finish and stamped weight codes. They usually mark them at the small end with carillo but not always.
So watch for the eagles...