What would YOU do?

[perfacar]

To Perfacar
The I.88 will pull, as far as you care to, just not as well as the 2.02s.

hi, then explain then how a 1.88 340 is as fast as a 2.02 340 in stock and super stock racing??? also, there 's a 273 with 1.78 valves , that runs 10.54 @ 120 + mph. in super stock. btw, these engines don't stop at 6000 RPM!!!! most stockers are at 7000 rpm +in the traps, super stock is more like 8000RPM!!

 

[Louie70Dart]

Thanks to everyone. Learned a lot here just now reading this. I have a set of j's and a set of x's that have had some bowl work and porting done. J's from a late 70 340, so 2.02's? X's of course have 2.02's. No questions, just appreciating the knowledge. MORE thinking.... LOL And Captain, any possibility of you being in the Zion or Winthrop Harbor shows this year?

 

[Captainkirk]

Thanks to everyone. Learned a lot here just now reading this. I have a set of j's and a set of x's that have had some bowl work and porting done. J's from a late 70 340, so 2.02's? X's of course have 2.02's. No questions, just appreciating the knowledge. MORE thinking....

Yeah, me too. Sounds like I may be better off with the 1.88's, honestly. Or shell out for a set of Eddy's (yeah...that's gonna happen. Not.)
Yeah, your J's would be sportin' 2.02's

LOL And Captain, any possibility of you being in the Zion or Winthrop Harbor shows this year?

Absolutely. I made Zion (Nostalgia Days) last year (tornado and all) and Park on Park in Mundelein (really good show, BTW...) a couple times (2nd Wednesday of the month from May thru Sept.) I try to stay away from Scoop the Loop; it's all low riders and buzz bombs.
Now, if you mean being actually IN the shows...with The Duke...no way. I'm still on the three year plan

 

[66fs]

Kurling restores a percentage of wearable surface to the guide. Oil clearance is set by honing the guide surface and oil control is done with a seal and control of oil to the top end. Once the knurling tool is used, a reamer is normally used to set the guide diameter. In this instance the problem is twofold: the kurling will only restore the wear surface near the tooling cut where the surface is deformed outward. This gives the machinst material to remove and set the stem to guide clearance. The reamer is tapered, so only the center of the guide is the rigth diameter. It's a repair process - not a hot rodding step, restoration to new, or better-than-new. And it leaves a far less accurate guide for the tooling that cuts the seats, and ultimately the valve stem. After the valve job is done the knurled guide becomes the "guide" for the tooling which can't cut a very round seat with the pilot in that guide. Check runout on any of those knurled seats. You'll know why the "negative waves".

Where ever you learned 5 angle valve jobs are bad was lying. The longevity of a valve job is comprised of the accuracy with which it's done, and the width of the actual seat angle. You can have a short-lived 3 angle, or a short lived 5 angle, or a long lived 5 angle depending on the roundness and width of the seat, and the fit of the guide. Loose (knurled) guides lead to bad valve jobs. Not the number of angles cut.

If you're eyeballing the port work then you're already placing far too much weight on your eyes. Flow testing is the only way to tell - and nothing you're stating is giving me good vibes about the choices or quality of this work.

Wow! that is the opposite of my experience. I've done both. Knurling, with the good tools, give a better center to the original seat and gives a straight full guide all the way through. There is plenty of displaced material to go undersize on the guide if you want. The only problems are, you can only do it once and you still have a cast iron guide. That said, we have a 273 with 300k on a set of 273 heads, no excessive wear or oil control problems. Granted it is a street car with the solid Commando cam so not a lot of lift or heavy spring pressure. As far as the heads go, I'd use the ones that would take the least to seal up and go. Flat gasket surface, good guides and good valve job. Either will go fast without much work.

 

[OldmanRick]

300k on knurled guides??? My experience on my first builds, that I earned when I was a kid just starting out, gave me about 3k miles before issues started.

My opinion, it's a bandaid, period. My first jobs were done by a few "somewhat" reputable local machine shops attatched to the parts stores. I learned real quick that it was nothing but quick fix for 99% of the work they did.....Regardless, you need to call Guinness, because you "are" the Man.



After my early/learning experiences, I ended up putting bronze liners in 75% of the street engines I put together with a 3 angle job. I had fairly decent results with them, and would probably do it today for most engines if need be. But, nothing beats a fresh/new, well clearanced, steel guide for performance/long term use, imo.

 

[OldmanRick]

Since I'm a nobody, this is a quote from a "Hod Rod" article...

"When rebuilding your heads, make sure the machine shop uses quality guides. If they insist on knurling your guides, find a new machine shop."

http://www.hotrod.com/how-to/engine/51058-cylinder-head-rebuild/


Yes I know it's from Jeff Smith, a Chebby guy, but I've been there myself, and I mostly agree with that article.

 

[Captainkirk]

Relax, guys....Guides are not an issue, really. Knurled or otherwise.....the knurling was done with the heads back in 1976...so it wouldn't break my heart to have new guides, seals, or even valves installed if I use the J heads. Same with the 5 angle valve job. Some of you guys weren't even born then. And I doubt the machinist who did the work is still alive to be offended by your comments...lol. Whichever heads I use need to be gone through, dipped and inspected and parts replaced as needed. I'm just trying to determine which heads to have worked; the 1.88 J's or the 2.02 X's. Looks like popular vote so far says the J heads for a street motor.

 

[OldmanRick]

Some of you guys weren't even born then.

If only Kirk...lol. I'd have a lot more years left in front of me .

As far as your choice, I'd still clean up those "J's", measure it, comp it right, maybe with gaskets?, and run the "wee" out of them. :thumbrig:

 

[66fs]

300k on knurled guides??? My experience on my first builds, that I earned when I was a kid just starting out, gave me about 3k miles before issues started.

My opinion, it's a bandaid, period. My first jobs were done by a few "somewhat" reputable local machine shops attatched to the parts stores. I learned real quick that it was nothing but quick fix for 99% of the work they did.....Regardless, you need to call Guinness, because you "are" the Man.



After my early/learning experiences, I ended up putting bronze liners in 75% of the street engines I put together with a 3 angle job. I had fairly decent results with them, and would probably do it today for most engines if need be. But, nothing beats a fresh/new, well clearanced, steel guide for performance/long term use, imo.

I used to rebuild engines, lots of them. Knurled guides in all the "virgins", aluminum bronze guides after that. Never had a problem with them or seats. Typically you need new exhaust valves on an engine with any miles on it. I learned from people who knew what they were doing, bought good tools, and would replace them when they were worn. We also knew how to measure everything and did not machine anything that was still good. 3,000 on a rebuild, why bother? We could easily get 100K on a throw together engine, used lifters and all. Just don't try that on a Chevy, you'll never find a good used Chevy lifter. As for Hot Rod Magazine, I used to read them, until I started hanging around real racers and machinists.

 

[OldmanRick]

Sounds like you did top-notch work :thumbrig:. Unfortunately, the early shops I used must have been more concerned with turnaround time then teaching a "green" kid what I took to make things right.

 

[Captainkirk]

If only Kirk...lol. I'd have a lot more years left in front of me .

Yeah, pretty sad when you start gauging projects by how much longer you; a) might be alive and; b) will be able to physically use the finished product.
Yikes! Time flies.....:blob:

 

[moper]

Relax, guys....Guides are not an issue, really. Knurled or otherwise.....the knurling was done with the heads back in 1976...so it wouldn't break my heart to have new guides, seals, or even valves installed if I use the J heads. Same with the 5 angle valve job. Some of you guys weren't even born then. And I doubt the machinist who did the work is still alive to be offended by your comments...lol. Whichever heads I use need to be gone through, dipped and inspected and parts replaced as needed. I'm just trying to determine which heads to have worked; the 1.88 J's or the 2.02 X's. Looks like popular vote so far says the J heads for a street motor.

Definately the way to go - build by popular vote...lol.

 

[66fs]

Sounds like you did top-notch work :thumbrig:. Unfortunately, the early shops I used must have been more concerned with turnaround time then teaching a "green" kid what I took to make things right.

Absolutely. I would rather start with an untouched motor with over 100k than one of those "rebuilt" engines. Sadly, I don't even have time to rebuild my own engines anymore.

 

[66fs]

Definately the way to go - build by popular vote...lol.

Luckily, either will be good with good machine work.

 

[Captainkirk]

Definately the way to go - build by popular vote...lol.

Well, that IS why I asked....rayer:

The 1.88-sayers are also mimicking what my engine guy said about smaller intakes on the street. I do like second opinions, though, and what I am hearing here pretty much sums it up...recondition the J heads and work the compression issues around them.
Funny how you can read things into generalized statements...such as "the 2.02 X heads produce more horsepower and are the rare, desirable ones"....well, for strip or track use, yes. For street use on pump gas; maybe not so much?
And now I have folks telling me that later "Magnum" closed-chamber heads (like the ones on my 5.2 Dakota) are better than open-chamber heads! Not that I would stray that far from the original design of the engine for this particular build, but interesting and fascinating nonetheless.
I wouldn't have considered larger valves to be a 'torque-limiter' on a street machine if it hadn't been pointed out. One naturally assumes more fuel, more air=more HP...which may be true, but not necessarily USEABLE street horsepower.
Learn sump'n every day...:coffee2: