I'm going to build a smooth idle 427 and drag test it
 

4.350 X 3.764 447 CUIN, I will use a Racetech piston with a 1.5 1.5 3.0 MM ring pack, compression will be set at 9.7. The center piece of my build will be a copy of a GM 350 HP 396/390 HP 427 hyd cam. My buddy @ Redline will grind it on a original 1960s GM cam core, I will have the LC changed from 115 to112, specs are 460/480/216/218/112, the goal is a dead smooth idle with complete reliability. Spring pressure will be set @ 120/300.
Comp Cams roller tipped rockers will be used with .083 wall moly 3/8 pushrods. I have new 1970s TRW hyd lifters to go on the cam. I used 1971 820 GM oval port heads (only because I had them) honed bronze valve guides, chambers cut on the exhaust side, 1.880/2.190 Ferrea valves installed, fully ported, surfaced and CCs set. For a intake I used a unmodified factory GM cast iron Q-Jet intake of course with a Q-Jet for the carb with a 1inch phenolic spacer. My two carbs were built by Harold Betttes and Vintage muscle car. I used a 402 cast crank with worked over GM rods, everything was balanced. My goal here was to run low 11s in my 68 Chevelle on pump gas with a dead smooth idle, why I have no idea.

Re: I'm going to build a smooth idle 427 and drag test it
 

What type of block and what was it honed on, can you list the head flow.

Re: I'm going to build a smooth idle 427 and drag test it
 

I love it! following. Whatever happened with the Buick?

Re: I'm going to build a smooth idle 427 and drag test it
 

Cool.. Only one question at the moment...Pueblo or Kearney?

Re: I'm going to build a smooth idle 427 and drag test it
 

New engine built, hav'nt run it since the wuhan virus. You can't except PMs. Send me your number and I will fill you in tomorrow. Or send me your Email.

Re: I'm going to build a smooth idle 427 and drag test it
 

959 production 454 block
280 grit hone, looks funny wet with hone oil

820 head castings, SF 600 4.350 bore @ 28 inches, Intake flow

.200 156
.300 225
.400 276
.460 292
.500 301
.550 312

The 820 casting is down on flow compared to other GM oval port castings, but I had them so they were used.

Re: I'm going to build a smooth idle 427 and drag test it
 

No thanks...............Houston:D Actually I'am really looking for high 10s with a smooth 750 RPM idle.

Re: I'm going to build a smooth idle 427 and drag test it
 

More pictures

Re: I'm going to build a smooth idle 427 and drag test it
 

Nice, but where are the oil pan pics ?? ......LOL. .....

Re: I'm going to build a smooth idle 427 and drag test it
 

No concerns going +.100 over with a production 2 bolt main block ?

Re: I'm going to build a smooth idle 427 and drag test it
 

Here you go...........Now I think I told you this could be illegal, but you said paint it black and run it:rolleyes:

Re: I'm going to build a smooth idle 427 and drag test it
 

I did sonic ck the block, and moved the bores accordingly. At this power level I'am not concerned, its well sealed up. This project was also about using parts I had lying around that I wouldn't use for a customer. When your constantly building higher HP engines, for me sometimes its nice to have a smooth idle mild engine on the dyno, and I was told by the experts on other forums the factory 350 HP 396 cam was a disaster that couldn't make power. I did a 350 HP 396 built back to factory specs but blueprinted a while back and it idled at 750 RPM with a very smooth idle and ran so nice, made 405 HP @ 5600 RPM, I really liked it and wanted to see what a 427 version could do.

Re: I'm going to build a smooth idle 427 and drag test it
 

More pictures

Re: I'm going to build a smooth idle 427 and drag test it
 

:Like a factory 385-390hp 427, only bigger. The factory did the same thing, even the 360hp & 390hp 454 in 1970.

Re: I'm going to build a smooth idle 427 and drag test it
 

I would guess that you would want a converter that's tighter than what's normally in the Chevelle.
I suspect the dyno test will bear that out. Nice job.

Re: I'm going to build a smooth idle 427 and drag test it
 

I have a hunch this will be far more potent than it looks.... :)

Re: I'm going to build a smooth idle 427 and drag test it
 

Nice pics, but your memory is suspect....LOL !!!!

Re: I'm going to build a smooth idle 427 and drag test it
 

Any readers here care to guess on the dyno HP ?

Don't be shy... No offense taken, I'll bet. ;-)

Re: I'm going to build a smooth idle 427 and drag test it
 

The cam is the obvious cork. The blueprinted 350 396 made 405 HP @ 5600 RPM with I think 408 cubic inches, so it would make sense it would be around 1 HP per inch, is what I was looking for. A better question is: how much average power over a certain RPM range does it take to run 11.00 @ 3500 pounds, anyone.............

Re: I'm going to build a smooth idle 427 and drag test it
 

The cam is the obvious cork. The blueprinted 350 396 made 405 HP with I think 408 cubic inches, so it would make sense it would be around 1 HP per inch, is what I was looking for. A better question is: how much average power over a certain RPM range does it to run 11.00 @ 3500 pounds.

Re: I'm going to build a smooth idle 427 and drag test it
 

Took something I had made a few changes and did a rough simulation.


DA = 0


60 Foot ET = 1.5076
330 Foot ET = 4.4113
1/8 Mile ET = 6.9378
1/8 Mile MPH = 96.7141
1000 Foot ET = 9.1421
1/4 Mile ET = 11.0173
1/4 Mile MPH = 120.2224


Stan

Re: I'm going to build a smooth idle 427 and drag test it
 

My guess is 500hp based on the very high quality of the build.

Re: I'm going to build a smooth idle 427 and drag test it
 

The first test is some what typical, and the second test was my best. From what I can see from the average power, that should get me there, 4200-6100 RPM (11.00) should be easy.

Re: I'm going to build a smooth idle 427 and drag test it
 

very nice!!

Re: I'm going to build a smooth idle 427 and drag test it
 

HP... I'm just wondering if you made any pulls starting at a lower RPM ? It would be interesting to see what the TORQUE numbers would be from say 2500-3500rpm. Very Good results from this project. MB

Re: I'm going to build a smooth idle 427 and drag test it
 

Thanks, I didn't pull it lower than 3500, I knew I'd never see that on the track, I doubt there was more TQ below 3500. I can tell you from driving the car off idle TQ is very good, but as you know theres always a trade off-and I'm sure it going to be on the top. But it sure runs good, just wonder what it could have made if I really got after it, intake work, oil pan work, lightened the bottom end up, 1.8 intake rocker, more compression. Vacuum was 15 inches @ 750 RPM @ 6400 feet altitude. Heres a video.
https://youtu.be/bJPHHWuifGQ

Re: I'm going to build a smooth idle 427 and drag test it
 

There is more torque at lower rpm. Look where the tq is at 3500 rpm. Your correct and probably never see it at the track.

Re: I'm going to build a smooth idle 427 and drag test it
 

Who did the carbs?

Re: I'm going to build a smooth idle 427 and drag test it
 

1. Harold Bettes Dissident
2. Vintage Muscle Car

Re: I'm going to build a smooth idle 427 and drag test it
 

whats the weight on the car w/driver?

Re: I'm going to build a smooth idle 427 and drag test it
 

3500 with no extra weight added.

Re: I'm going to build a smooth idle 427 and drag test it
 

I see 10.83 or .84 at sea level ;-)

Re: I'm going to build a smooth idle 427 and drag test it
 

Mark,

Have you had a chance to get this combo back on the track yet? I would seriously be interested in seeing two things. 1. What a ported intake would do. 2. What a modern lobe would bring to the table.

Re: I'm going to build a smooth idle 427 and drag test it
 

The week of July 13 it will be tested, I will let you know.......

Re: I'm going to build a smooth idle 427 and drag test it
 

Time for the rubber to meet the road, smooth idle 427 drag test Saturday........

Re: I'm going to build a smooth idle 427 and drag test it
 

7.09 @ 93.2 MPH, 1.53 60 horrible track prep
4520 DA
130 grains of water
27.86 Barometer

Re: I'm going to build a smooth idle 427 and drag test it
 

Well now... Good show, Marky

Re: I'm going to build a smooth idle 427 and drag test it
 

Heres what happened:

My car weighs 3720 with 140 pounds of extra weight added in the rear ready to race, I did not have the extra weight in the car which made it weigh 3580, but you have to take into account the iron intake, which probably put me at 3600. When you race at a mid west altitude track (2130) track in the summer you can ONLY expect horrible conditions, and it seems every time I go to this track theres more problems making runs, I need runs to develop combinations, thats why I drive 800 hundred miles round trip. So when you look at the conditions, well they don't look so bad

27.87 baro
130 grains of water
4500 DA

Well let me tell you, the 130 grains of water is the problem, and that becomes a tuning problem, especially when you have no runs to tune.

1st run spun the tires, run aborted
2nd run spun the tires run aborted
3rd run first round, dialed 11.49 caught the person I was running against @ 900 feet and door raced him to the finish line
4th run, time only waited and waited and waited to run until I had 140 grains of water, they just got done running all the power adder POS cars and finally they pulled me out, I had my tires set for a compromise to get out of the whole 19 PSI, any less they wadd up, I launch to a dismal 1.530 but hooked, at about 500 feet out I feel the car break traction, I pedal it and get back on it (remember the POS power adder cars before me) and run

1.530
7.09
11.29

So after this I was so pissed I put the car on the trailer and left. I knew going out there not to expect much, I would have been better running at Bandimere and correcting the the times, but your not going to get any runs there either, but you can expect the track to work, and you will not be working the water problem.

But you need to remember which I think most don't understand about this engine, it has a production camshaft, the exact same cam that came in your 1960s 350 HP 396s and 385 or 390 HP 427, but with 9.7 compression, what can you really expect from this smooth idle engine with a car with 4.56 gears and a 8 inch converter. I can guarantee with the right converter and gears run in the right conditions the out come would be entirely different.

Re: I'm going to build a smooth idle 427 and drag test it
 

What track were you at?

Re: I'm going to build a smooth idle 427 and drag test it
 

Kearney, NE