Has anyone got any real experience with the GM 5.94" rods? I've heard some say they're as good as the older "pink" rods used in the LT-1 and L-82 350s of the early 70s. I had good luck with those rods, with two exceptions, but I need some info on the durability and peak rpm range I expect to take these rods to using ARP pro-series bolts.

I'll be using a 400 block and destroking it to a 377 or 326. If I go 377 I can use aftermarket 5.7 rods, but I've always wanted to build a 326 using a 400 and 3.00" crank, like a .155 over 302 if I go +.030 bore. If I go with the 302 crank I'd need to use the 5.94 rods to keep it -.025 in the hole, 6.0 rods would be too long.

If the 5.94 rod with ARP bolts won't hold up to 7500 rpm then I guess I'll go back to the 377 plan and less gear. But I've never been to happy with a 3.48 stroke motor.

Thanks for any experiences you can share.

Dave

SY1,

I guess I worry about PM rods being just a schosh too brittle even IF they say they have been enduranced tested for longer and at higher levels than the old "Pink" rod! I know a true forged rod is TOUGH but I don't know how tough the PM rods ultimately are?? Strong, SURE, but TOUGH??

Please consider using a 6.25" rod and a 400 piston made for a 6.00" long rod for the 3.00" stroked motor!

I figure if this stuff is good enough for the roundy-round guys, it should hold up in a motor like you are talking about and the prices should be decent to me. Probably like $600/$700(??) for a set of long rods and needed forged pistons...............

pdq67

ttt.

Dave,

What did you decide to do??

pdq67

Pdq I'm thinking you're right about the PM rods. I can certainly get a much better after market rod for a little more money. As long as I'm destroking it there is no point in skimping on the rods because the only reason I like the short stroke motor is to run more gear and to "take it upstairs" now and then.

The project is getting shelved again for a short while. I've been away more than home so far this year, and I'm leaving again next week. Maybe I'll get things rolling in June!

Dave,

What are your thought's on the 6.25" rods for the 3" stroked motors??

pdq67

Dave,
Let me know what you decide to do. Dad is trying to decide what to do with his Aluminum 400 block. He wants to use either a 350 crank or a 302 crank, but can not decide which directiobn to go.
Be safe in your travels,
Chris

pdq if I'm doing my math right the 6.25 would leave me .130 in the hole using the shortest comp height 400 piston of 1.125. I could use the 6.25 with a LJ 327 crankshaft and be .025 in the hole, just like the General designed. That's a consideration at 352 cid. Been on the road so I've been away from the website a few days. In Little Rock this week. I could get excited about the 3.25 stroke 4.155 bore motor, a little less gear, say 4.56 or 4.11 and a 4 speed. Might be fun, could still go upstairs on the tach with a lot less worry than I'd have with a 3.48 stroke, I've destroy a few of those pretty quickly so I'd like to stay away from them.

Chris thanks for the note. Is the new motor for the Corvair? How's the Camaro coming? Getting close to paint yet? Let me know if he decides to build the aluminum motor and how things work out for him with it.

Dave

You are probably right b/c I probably forgot about a stock 400 rod being .135" shorter than a 350 rod is all..

Anyway Dave, you got my idea of using the 6.25" rod and a longer rod custom oversize 400 piston so everything would fit together...

Thanks.

pdq67

Your just north of me an hour and half. What brings you to the most buitifull state in the union?

Joe

I have frequently turned powder metal rods SBCs to 6500 and abused newer EFI LT1 350s for years. Never had a rod problem. They are frequently used as an alternative to aftermarket rods by round track racers that are restricted to GM parts in their division. The Powder Metal rods are great in my racing and endurance experiences 0-6500 rpm in 300-350hp small block motors. I wouldn't hesitate to use them again. That's my experience with them. I give them an A+!

Thanks Neil for the input. I'm probably going to go with a little less stroke and a little more top end rpm, but it's good to know you've been quite happy with them running them that high in a 3.48 stroke motor. I haven't been as sucessful using the older pink rods in L82 3.48 stroke motors myself. So the next motor will be another short stroke motor.

Joe I'm here for airframe maintenance recurrent training. The aircraft I crew chief are completed here when they come over from France and this one of the locations they offer the training. I got tired of the New York area, this is a real nice change. Very beautiful country here I agree. Like Northern Michigan, but with sunshine!

Dave,
The new aluminum motor might find its way into the V8 Corvair, but I doubt it. Dad is talking of selling it and buying a Camaro.
My Camaro, on the other hand, is not close to paint but is close to it's first drive. I just fired the 12:1, roller cammed 427 the other day. :)
Are you still lighthouse watching? Be safe in your travels my friend.
Chris

How long are you here? or are still here?

Joe I left Little Rock on Friday. Back in Michigan now. I got down to Hot Springs one night, but the rest of my time was spent at Little Rock airport. Weather was great!

Chris did you give your dad the Camaro bug or what? That's surprising he's considering changing from the Corvair. So the ground shaking clear up here in Michigan last week was the Camaro firing up! That's a great day when you fire up the motor for the first time. Hope everything went well. Didn't do much lighthouse touring last year. Maybe this Summer, we need to get out more. Hope everything is going well for you.

Dave

Dave,
Yeah, I rubbed off on Dad. :)
He is on the fence.....every time he drives the Corvair he says "I better keep it", but every time he is around my Camaro or his brothers Camaro he says "I need one of these". LOL!
The new engine fired up just fine and sounds great. I have a hundred small things to complete....then it will be coming out for it's first drive (just installed the windshield today).
Be sure to keep me posted on your new engine. Did you ever get another Camaro?
Chris

2 cents in the pot,,, I destroked a 3.480 crank offset .090 and used 6.0 rods with 4.030 bore. . That produced a motor that was just a tad over 327 stroke and had lower bearing speed. Used the small journal rod from Brooks. At that time there were not steel small journal rods. Sung many songs at 8000.

Chris sounds like he's been "bit" by the Camaro bug! Just a matter of time now. I haven't found the next first gen yet. I've been gone more than home this year so far. When I'm away from home, but still in the states, I've spent a lot of time looking for the right car. Just no luck yet. Spent 3 week in AZ from Tucson to North of Flagstaff and only found 1 that interested me, a 68 RS 4 speed car. Nice car, but the stripes were laid out wrong which wouldn't be too bad to live with except the fact that only half the fender engine CID emblem was inside the stripe and the other half was on the base color really made it look odd. Wife says I'm too picky, she's right, she always is right. I just got back from a week in Little Rock and didn't see a single Camaro there. My last day there I found an ad in the local paper for 69 X11 4 speed body, price was right, but I didn't get over to see it. The first week I was in AZ the car I would have liked to have I found in Kentucky for sale. Very nice 68 RS blue with black top. I wasn't willing to buy it without seeing it (I learned a lesson with the last 69) and it was gone before I left AZ. One of the problems is I'd like a southwestern body without air, most of the cars I've found that are dry clean bodies have air.

I've been trying like crazy to buy the 68 coupe from one of my friends at work. It's corvette Bronze, original paint, 52,000 mile # matching car. Base car 327 with a power glide, don't care for the trans but I could change that, even though it would be a sin on a car that nice. It is one of the nicest unrestored original cars I've seen. He bought it about 7 years ago when we were together in Wichita. I'd just bought my 68 RS and told him if he could have first crack at buying it because I'd just picked up the RS. He bought it and I've lived with my decision ever since. I know when the time comes for him to let it go I'll get the first chance at it, so someday it'll be mine. In the mean time though I need to find another one to play with. He doesn't drive it and is already tired of it, but his wife won't let him sell it yet.

Don't worry too much about the 100 little things. Get it to where you can drive and enjoy it. I've looked at a lot of first gens the last few years that were supposed to be completely restored that still needed hundreds of little things. Enjoy it and continue making progress with it. The first drive will be memorable.

Dave

Zdld that's good info. Did you find it expensive to offset grind a crankshaft? I'm wondering if any machine shop can do this or if special equipment is required. You'd certainly want someone experienced doing the work.

That 8000 rpm buzz is music to my ears!

Thanks for the update Dave. I really hope you get that bronze car. I just love that color on a 68 Camaro (mine might end up with that color). I just spent the day working on the front end alignment. I have it straight enough to get it to the alignment shop now anyway. You are right about the 100 things..... I am so close to driving this car that it is driving me crazy! :) I might even get to make a pass or two at my local strip this summer (or Fall).

Try not to be too picky my friend. I want you to have another high winding Camaro!
Chris