# Dyno Time!



## leeklm (Mar 11, 2012)

Picked up the new powerplant on Sunday, which the builder still had setup on his test stand for breaking in the cam. Was fun to hear the motor run and see good oil pressure and about 20" of vaccum, which the power brakes will appreciate! Assembly was balanced, and ran very smooth on the test stand. I was surprised at how smooth & quiet it was, which may be in part from the small factory exh manifolds and small exhaust pipes that were part of the break-in stand.

Now, scheduling for the dyno on Presidets Day. I will post back with results, and will also make runs on full length headers and my new Ram Air manifolds. 

For reference here are the motor specs... Any guess on HP & TQ numbers??

--455 +.030 KB Pistons- zero deck
--Eagle H beam rods on stock crank
--7K3 heads w/pocket porting (Head flow was 215 intake & 145 exhaust)
--800cfm Qjet on factory 72 manifold
--1.5 roller tip rockers
--Lunati Hyd Cam with following specs...
Advertised Duration (Int/Exh): 262/268
Duration @ .050 (Int/Exh): 219/227
Gross Valve Lift (Int/Exh): .468/.489
LSA/ICL: 112/108
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1300-5500
Part Number: 10510702LK

Looking forward to Dyno Day!

arty:


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## BearGFR (Aug 25, 2008)

What? No video of it running yet? :willy: I'm disappointed in you, bro...

Bear


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## leeklm (Mar 11, 2012)

yeah, me too! I only had the "basic" phone with me, no video!


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## lars (Sep 28, 2004)

Are we doing a bet pool on the power & torque numbers...?
:cheers
Lars


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## Instg8ter (Sep 28, 2010)

i'll give it a shot....456/502


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## leeklm (Mar 11, 2012)

Those are big numbers, i hope you are right!

Sent from my DROID2 GLOBAL using AutoGuide.Com Free App


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## Eric Animal (Oct 28, 2007)

425/475.....arty:


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## leeklm (Mar 11, 2012)

My best guess is from the numbers that Bear ran on his dyno software, which was 440/496. Here are a few pics after paint. The yellow wires have to go, but were the only ones I had! 

One of the pics is up close of the stud that is used to help the manifolds seal on my 7k3 heads. As you can see, that particular spot on the manifold is not drilled all of the way through. 

Just curious, were the factory RAM AIR manifolds also missing the hole?


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## Eric Animal (Oct 28, 2007)

A thing of beauty! You can drill the holes since the boss is there. Eric


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## lars (Sep 28, 2004)

400/420
:cheers
Lars


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## geeteeohguy (Feb 2, 2008)

435/501!!


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## ALKYGTO (Mar 29, 2010)

325/455 

















At the wheels............arty:


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## leeklm (Mar 11, 2012)

had me worried for a second...


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## leeklm (Mar 11, 2012)

Drum roll.....

It is amazing how fast a 4hr dyno session fly’s by!!! All in all was good, but chasing a few carb issues that lost some time, but that’s what the session is all about... here are the results:

Qjet & Headers
HP = 411 @ 5000
TQ = 506 @ 3200

Qjet & RAM AIR Manifolds
HP = 396 @4900
TQ = 495 @ 3200

We also tested a Holley 750 vac secondary connected via a square bore to qjet adapter (had 4 separate holes that transition, was not "open"). The results reduced HP by a few, but actually gained a little tq. Was not enough difference to worry about. My guess is that we can probably get a few more horses with some carb tuning, but just did not have the time.

The attached graph is showing results from headers & manifolds. The dyno guy was impressed with the manifolds and commented " I would not fool around with headers on a street car with those results." 

On the attached dyno sheet, you will see a sharp drop in hp at just over 5,000 rpm, which was from the lifters not being able to keep pressure up. I was a little surprised/disappointed to see this with new lifters (bought from Lunati with the cam). So if I do not change anything, my redline will be 5K, which is ok too for my use, and may save on other parts.

Final observation on my cam is that I would not mind a little more "lope" at idle, just for effect. But, it will make a nice street engine with a nice & smooth idle and lots of TQ!

Oh yeah, we did have a leak on the front seal that I need to fix. Builder said he put a sleeve on the old balancer that is likely giving us problems, so time for a new balancer. Much easier to fix now than if I had it running in the car!


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## leeklm (Mar 11, 2012)

Looking back at the estimates, looks like we have a split decision! HP goes to LARS, and Torque goes to Geetee!


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## BearGFR (Aug 25, 2008)

Nice numbers - now where's our video??? 

Bear


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## 67GTO4SPD (Oct 4, 2012)

Nothing at all wrong with 400HP/500TQ with factory heads, intake, Q jet and exhaust manifolds.


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## leeklm (Mar 11, 2012)

Motor and trans (my first 4spd overhaul) is in, and gave it a test run on the jack stands since we are still under a foot of snow. Trans & new clutch shifted great, helps having the right fork, etc!

Anyway, the engine is running decent, but chasing down some carb fine tuning. It was strange that a Holley 750 and 2 qjets (one previoulsy running great on my smogger 400) all ran about the same! 

Just for Bear, I included a couple of videos here! I was challenged with dvd camera, so did not do any editing. It looks like it is running plenty rich out the tail pipe, but I suppose part of that is from flicking the throttle with no load, dumping lots of gas in there! BTW, the "crackling" you hear at high RPM on one of the runs was because I left the secondary rods out... oops, was getting plenty of fuel that time... Oh yeah, and the loud "whirring" noise you hear up front are my electric fans.

All of the throttle jabbing you hear was due to me trying several differnt carb/jet combos.

Video... VTS_01_1 - YouTube

VTS_02_1 - YouTube


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## geeteeohguy (Feb 2, 2008)

Sounds great! The smoke appears to be bluish, which indicates oil. Could be the over rich condition that you had diluted ihe engine oil with gas....pull and smell the dipstick. If it smells of gas, change the oil. Also, it's a new build. The rings will seat with usage and things will clean up. VERY nice '66!!


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## ALKYGTO (Mar 29, 2010)

:agree And +1 to you having a beautiful GTO! :cheers


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## BearGFR (Aug 25, 2008)

Now you're talkin.... 

:cheers

Nice!

Bear


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## Nz66gto (May 28, 2016)

Afr problem Hi first dyno test on my 66 Gto was a bit of a disappointment but still a fun day my max rwhp was 250 at 4697 rpm max torque 305 3391rpm but my main problem was afr top reading was 13.9 the dyno guy said it was to lean and engine needed more gas he put a fuel pressure gauge on to test and it was 5-6psi at 2500rpm then dropped to 1.2-1.5 at 3500 rpm does that sound low it's a mechanical fuel pump and I have tripower set up 400 engine.cheers for any ideas help.


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## 1968gto421 (Mar 28, 2014)

Nz66gto said:


> Afr problem Hi first dyno test on my 66 Gto was a bit of a disappointment but still a fun day my max rwhp was 250 at 4697 rpm max torque 305 3391rpm but my main problem was afr top reading was 13.9 the dyno guy said it was to lean and engine needed more gas he put a fuel pressure gauge on to test and it was 5-6psi at 2500rpm then dropped to 1.2-1.5 at 3500 rpm does that sound low it's a mechanical fuel pump and I have tripower set up 400 engine.cheers for any ideas help.


You may want to start a new thread with this, rather than attaching it to an older, previous post by another member. It would probably get better response, especially if it was under the Engine Tuning and High Performance header. Just a thought.


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