[mgarblik]

We ran a student's bone stock 400 engine last night on the dyno. We do very few completely stock, restoration grade, engines but this was a good example. 1968 GTO base 400 engine, manual transmission, 350 HP factory rating, 445 ft. lbs. factory rating. Everything bone stock. You often hear various engines, manufacturers, had inflated or underrated engines when new. This is the second engine in recent memory that proved that not to be the case. This engine made 441 Ft. Lbs. peak torque @ 3800 RPM's. It made over 400 ft. Lbs over a 1500 RPM range. Peak HP was 353 HP @ 4900 RPM's. It made between 350-353 HP from 4800-5400 RPM's and slowly trailed off. We shut it down at 5700 RPM. Very close to the factory rating.

Couple years ago we ran a restoration 327-275 HP Chevy engine for an Impala. It made 271 HP peak. So it seems some factory ratings were pretty darn close. FWIW.

Anyone else have similar or different results with bone stock engines?

[Stan Weiss]

Great numbers. Would you happen to have a dyno sheet that you can post?

Stan

[JB Eng Wis]

Cool, im just guessing that ment you had #16 heads and the 068 camshaft?
or am i off a bit.....please advise

[Skip Fix]

When i had to swap to a 400 to use my RAIV heads in the old NMCA top Stock class, they had a class the year before I could use them on my 455, with an UD 288/296 cam but same 0.050 as a RAIV cam and headers it dynoed 385 HP on a stingy dyno so pretty close to factory numbers. But NMCA had it "factored" about the same as a 429SCJ so in class they were tough to beat.

[steve25]

Was this test with the motor spinning a Alt?

I am assuming a 067 Cam that would have been used with 4 speed, but not the 068 Cam used in the 400 ho motors?

[72projectbird]

Some are damn close to factory, some are way off in both directions.

Pretty cool to see an actual baseline. I hate watching/reading about "stock" dyno tests only to find out they're running a 4150 Holley on a single plane, dyno headers, no accessories, and a modern ignition system among other things.

[srmmmm]

I recall a dyno test on a 1968 350 HO that had a fresh rebuild to stock specs other than an .030 bore, It came within 5 horsepower of the factory rating. It was only spinning the water pump and had exhaust manifolds, so provided a reasonable comparison to factory methods.

[hurryinhoosier62]

Originally Posted by mgarblik

We ran a student's bone stock 400 engine last night on the dyno. We do very few completely stock, restoration grade, engines but this was a good example. 1968 GTO base 400 engine, manual transmission, 350 HP factory rating, 445 ft. lbs. factory rating. Everything bone stock. You often hear various engines, manufacturers, had inflated or underrated engines when new. This is the second engine in recent memory that proved that not to be the case. This engine made 441 Ft. Lbs. peak torque @ 3800 RPM's. It made over 400 ft. Lbs over a 1500 RPM range. Peak HP was 353 HP @ 4900 RPM's. It made between 350-353 HP from 4800-5400 RPM's and slowly trailed off. We shut it down at 5700 RPM. Very close to the factory rating.

Couple years ago we ran a restoration 327-275 HP Chevy engine for an Impala. It made 271 HP peak. So it seems some factory ratings were pretty darn close. FWIW.

Anyone else have similar or different results with bone stock engines?

Mike, that is going to be one sweet street engine!

[Lee]

Did you use stock exhaust manifolds, or dyno headers?

[PAUL K]

Cool build. Thanks for sharing.

Peak horsepower seems to be about the same as an LS-1 engine but those torque numbers are much better.

Did this engine use the 288/302 HO cam?

[JSchmitz]

Originally Posted by PAUL K

Cool build. Thanks for sharing.

Peak horsepower seems to be about the same as an LS-1 engine but those torque numbers are much better.

Did this engine use the 288/302 HO cam?

Which 400 cubic inch LS engine torque numbers are you referring to?

[JSchmitz]

Thanks for sharing the dyno info!

[mgarblik]

Quite a few replies so I will try and answer some questions best I can. Dyno screen shot or print I can try to get in a week or so. School shuts down for a week between spring and summer classes so I can't get in the building. But I will post when I can get back in. Cam was a Melling 068 clone. I thought the stick cars got that cam, I may be wrong. No engine driven accessories, electric belt driven water pump, no alternator or mechanical fuel pump. Stock ignition, no box. Log manifolds, 3' extensions, no wide band. Not sure of head castings, Whatever was original to a 68 GTO. Stock rocker arms, stock replacement valve springs and pushrods. Stock valve seats with a nice but basic valve job. Only real deviation internally was the switch to cast dreaded 8 valve relief pistons. They were the only cast pistons available when he needed them. Used against my recommendation but seem to be fine. Piston to wall .0025". I did warn him of possible detonation and the need for premium fuel and limited total timing. To be safe, we ran at 32, 34, and 36 degrees timing. Made 3 HP better peak HP at every change, but to be safe we stopped there. Engine had zero blowby and zero leaks. Everyone went home happy. Broke the cam in with outer springs only for 40 minutes at 3000 RPM between 10-20% load. Always worried about flat tappet cams. We were 4 successful flat tappet cam engines this year and zero failures. Most engines are roller hydraulic or solid roller cams. Last year we lost 3 cam lobes in 1/2 hour on a little 260 Ford 2 bbl. engine. Probably 200 HP. So you just never know. Had to take it totally apart and clean everything and put it back together. He went hydraulic roller second time around. Added $1200.00 to the cost and it made around 245 HP. Very mild build for a Falcon Sprint

[b-man]

The cam originally used in a non-HO 1968 GTO 400 with a stick would have been the 067, auto trans the same.

Very nice numbers, right off the showroom floor these cars more than held their own even with the standard 400.

Must be quite rewarding working with those students and running the dyno on their various engine builds.

[steve25]

Ok so the deal in 1968 was that the 068 cam was used in only 4 speed cars.

It could have had casting number 16 if it was a Ho motor, or casting 31 if it was a Early RA 400.

Both where rated at 360 Hp, so the dyno test still had close enough results for me, especially since the better RA/ HO exh manifolds where not used.

[PAUL K]

Originally Posted by JSchmitz

Which 400 cubic inch LS engine torque numbers are you referring to?

Referring the the LS1 that came in the late 90's early 2000 F-bodies..... The funny thing is a lot of folks think the 5.3 LS engine is superior

[Gach]

Yeah my 68 GTO 4 speed which I bought bran new was rated at 350 hp. Ran 12.70’s. Not many modifications. So your right hp wasn't over rated. Only thing I did was add header’s and 4:33 gear, recurve the distributor. Thing would float lifters if I went any thing over 5500 rpms. Guessing it had 068 cam from factory. I believe it had number 16 heads.

[Gach]

Must be a real joy working with and teaching young kids. My grandson who’s 10 years old is so into the GTO. When putting motor together he had a million questions. Every day he would ask me papa you working on the motor today Loved it. Something he’ll never forget.

[steve25]

Gash if it was a 350 Hp motor then it would have had the smaller 067 cam, # 16 heads and log type exh manifolds.

Those springs on those 16 castings only had 270 psi of open pressure which explains your valve float @ 5500.

This would have made your track times even more impressive!

[mgarblik]

I enjoy the class very much. You have to really keep a close eye on what's going on because the student's provide the engine and the parts. Of course you never want bad results or worse, some kind of actual failure, which is rare. The students have a written plan when they come into class, with goals, uses for the engine, and a budget. Once approved, away they go. Wide, wide variety of engines and I love that. Lowest HP engine we ran on the dyno was an accurate replica of the first Wright Brothers engine for powered flight. This was done in 2003 for the 100th anniversary of flight. The replica was an aluminum cast block, gravity water cooled as original. It made 11.8 HP and it did fly a couple months after being on the dyno. Extremely pleased with that project. On the flip side we had a twin turbo Big Block Chevy over power our dyno at 3500 RPM's. At the time, we could only absorb torque to calculate 1000 HP. We have since upgraded to 1500. This is the 25th anniversary of the "High Performance" engine courses at the college. I started the program with a valve grinder, a wet surfacer, stone seat grinder and a mill. This semester student ages were from 17 years old to 83. Oldest engine a model A Ford. Newest was a 6.0L LS. Interesting mix this year, Ford 385 series stroked to 541, Ford real Boss 302, Chrysler 426 Hemi, 440, 3.9L V-6 for a Dakota, 2 LS engines, 2 Small Block Chevies, 1 Studebaker V-8, 1 inline 6 Studebaker, 1 Pontiac 400, 1 Toyota Supra Turbo. Few others. A really nice mix. As a retired "re-hire" I do this stuff almost for free. But I do enjoy it and I have a great co-instructor who is a Ford specialist. So it all works out. He was primarily responsible for our 3 engine masters entries. We placed in the top 5 every time and had one 2nd with a Ford of course. BTW, the entire course is 320 hours. 10 hours a week for 32 weeks. So there is plenty of time to do a nice job on a single engine project. Start second week of August and finish Early May. With about a month off around Christmas.