Making redline in a 340 SHP

[Jim C.]

Second question for folks with experience with this motor. All things being equal, with a well rebuilt 63 340 SHP( forged crank, Crower rods, forged pistons, rebuilt heads, 3.70 posi. etc) historically does this motor tolerate running to red line well(6000 rpm) ? Did it have any specific weak areas that would preclude or give me pause from going there?

[Larry M.]

Re: Making redline in a 340 SHP

Jim:

I think the original rods were a problem, but since you replaced them with Crower's you should be good to go.

Larry

[William C.]

Re: Making redline in a 340 SHP

Used to shift all the time back "in the day" at 7000 without engine issues, They are pretty stury pieces.

[Duke W.]

Re: Making redline in a 340 SHP

The Flint-built engines would make useable power to the redline, which is 6500. On a rebuild, top end power is a function of the quality of the valve work, and head massaging, if any.

The weak link in these engines is the OE rods, and the Crowers will make it bullet proof unless it gets oil-starved.

I have a lab dyno test of a .040"-over 327/340 - nothing special, just a bore, new OE pistons, bearings, etc, and a standard valve job.

It made the OE advertised SAE gross peak torque, but the SAE gross power peaked at 295 at 5500, which is about what they really made as built by Flint.

The test didn't go beyond the peak, but the falloff to 6500 was probably modest as the SOTP feel of my 327/340 was that it was still making useable power to 6500.

With some head massaging and the LT-1 cam it's a real high rev screamer - about 350 honest SAE gross HP at 6500 with just a little rolloff to the 7250 valve float speed with the same idle and low speed behavior.

Duke

[Rich P.]

Re: Making redline in a 340 SHP

Back in the early 80's one of my old bosses had a 65 365 coupe. I was in that car on numerous occasions when it hit north of 7000. I know the tacs are not the most reliable in these but that motor used to sing. it had 4.11's

Rich

[Domenic T.]

Re: Making redline in a 340 SHP

I agree with the reply's,
The only weekness I found was the owner that neglected his engine which is not the case here.
The only thing I found was #1&2 rod bearings would starve for oil at extended high RPM and both end up on one half of the rod, rod cap, or just weld to the crank. #1&2 are the last to get oil. You notice the extra quart your oil pan holds, that helped keep enough oil at the pump to get there at high RPM's. Also those were owner abuse problemsI found when draining only 3 qts of dirty oil out of the pan and usually a shifting novice that missed a gear and forgot to let off the gas.
What a wonderfull 2 bolt main that 327 is.
HP can be viewed as the amount of air you mix with fuel and turn into power. The 327 could move it faster than the big block and at a higher RPM thus moving more CFM thru the engine that created power.
I have a 365 HP and a 435/427 in my vette's and the small block is just amazing.

DOM

[Stuart F.]

Re: Making redline in a 340 SHP

My L-76 is all original in that the heads, manifold, clutch and rotating assembly have never been apart. It now (the car) shows a little over 44k on the odometer. I did put on a new timing chain/sprockets and check the oil pump when I dropped the pan to remove a major dent - all in the name of preventive maintenance. All other internals including the valve train are original (cam, springs and rockers, etc.). I have a 3.36 final and have almost always been able to see 7000 rpm in 1, 2 and 3 gears, and have pulled 6200 to 6500 in 4th (Nevada 1963). It is far more consistent now then in earlier years due to electronic ignition, and the clean plugs it affords. My AFB has been tweeked primarily to deal with today's gas. I run an aggressive ignition advance map with a Dynaflite plate and Pertronics II (direct 12v input), and use premium gas w/Max 2000 TEL additive.

I have owned a number of SHP Chevy V8's in my days (283's, 327's and 350's) and all have been free revers. I have raced for several seasons and have yet to experience a catastrophic failure. Just my good fortune I guess.

Stu Fox

[Jim C.]

Re: Making redline in a 340 SHP

I agree with the reply's,
The only weekness I found was the owner that neglected his engine which is not the case here.
The only thing I found was #1&2 rod bearings would starve for oil at extended high RPM and both end up on one half of the rod, rod cap, or just weld to the crank. #1&2 are the last to get oil. You notice the extra quart your oil pan holds, that helped keep enough oil at the pump to get there at high RPM's. Also those were owner abuse problemsI found when draining only 3 qts of dirty oil out of the pan and usually a shifting novice that missed a gear and forgot to let off the gas.
What a wonderfull 2 bolt main that 327 is.
HP can be viewed as the amount of air you mix with fuel and turn into power. The 327 could move it faster than the big block and at a higher RPM thus moving more CFM thru the engine that created power.
I have a 365 HP and a 435/427 in my vette's and the small block is just amazing.

DOM

Hey thanks for the replies from all, Dom I have a 5 quart pan on my car at the moment, would you think there would be an oil starvation issue if the pan is full?

[William C.]

Re: Making redline in a 340 SHP

I'd certainly go with the 6 qt pan if you want to extend the life of the engine under high RPM excursions.

[Michael F.]

Re: Making redline in a 340 SHP

I'd certainly go with the 6 qt pan if you want to extend the life of the engine under high RPM excursions.

That 6qt unit is difficult to find.

[Stuart F.]

Re: Making redline in a 340 SHP

I'm sorry, but was this a factory option I wasn't aware of (possible) or are we confusing the total capacity w/filter of the SHP (L-76 & L-84) of 6 quarts (5+1).

Stu Fox

[Duke W.]

Re: Making redline in a 340 SHP

All '63-'65 mechanical lifter cam engines used a 5 QUART capacity oil pan. With filter the SYSTEM CAPACITY is 6 quarts.

Road racers learned to overfill the above pan by one quart, so they started races with seven quarts, and for the available tire grip of the era it was usually okay.

The hydraulic lifter engines used a FOUR QUART PAN, five quart system with filter.

The four-quart pan deep part of the sump extends about halfway the length of the engine and the five-quart pan about three-quarters the length of the engine, so they are easy to ID.

Anyone who has an original or rebuilt original with the OE rods is risking their numbers matching block. All these mechanical lifter engines have the early, weak rods. By the time the stronger second design rods came along in 1966, super-revving mechanical lifter 327s were history.

If for no other reason - to save you block, rebuild the engine with better rods or don't go over 5000.

At 115K miles when I rebuilt my 327/340, the number seven rod had a crack right at the bolt seat, which is the weak area. I may have only been a few redline trips away from a blown engine, and a lot of 327s in that era had short lives from broken connecting due to fatigue and the stress concentration at the bolt seat.

Duke

[Bob H.]

Re: Making redline in a 340 SHP

I just had mine rebuilt using Eagle rods. I have the 6 qt oil pan and the duntov cam. It pulls very strong right up to 6400 and beyond. No problemo.

[Jim C.]

Re: Making redline in a 340 SHP

Think I will drop in an extra half quart of Rotella tomorrow and run it to six grand and see how big a is on my face. It'll be in a straight line anyway with no lateral G's.
Just want to hear a mechanical lifter engine at speed again!

Thanks for the replies, think it is as good to go as it will ever be.

[Bob H.]

Re: Making redline in a 340 SHP

Heck, I have the 4.11 rear in my 63' so my biggest concern with my solid lifter 327 is that it hits the red line so quickly, smoothly and powerfully that I have to keep an eye on the tach so I know when to shift. Usually other SBC's with hydraulic valve trains you would just shift when the valves floated and the power tapered off.......hehehe