Discussion in 'Street/strip 400/430/455' started by Cutlass, Sep 5, 2019.
200r4, beefed up by Extreme Automatics
I would love to put a th200 behind my race motor if I thought it would live, thecweight savings from a th400 would have to make several tenths for certain.
Glad it was something stupid that gained your power back, but if your motor has 20% leakage, something isn't right there still
I am with you, but I am getting to the conclusion, that most likely I was to cheap when buying the tester. The good thing is, that the leakage rate is almost the same on all the cylinders, but cyl3. I will keep an eye on it and maybe have the test performed at a dealership for confirmation.
Yesterday I ordered the advance kit from Summit, will see how long it takes to get to my doorstep.
Question: The Kits come with one bushing. This is meant to be a replacement for lost/wornout stock bushings. I can not adjust the total mechanical advance with this bushing, right? If I need to adjust the max angle of mechanical advance I need to weld & grind, right?
If there is currently no bushing on the advance pin, the bushing in the kit will reduce the amount of mechanical advance.
Today was the day and I had the Buick back on the chassis dyno.
For those who do not want to read the whole thread; in a nutshell:
Last years measurement resulted in 196 PS @ 4270 1/min. Reason was my stupidity, I accidently mispluged cylinder 2 & 6 at the distributor cap.
Along this year I did set the distributor according to Larrys thread and installed a Pertronix module
Also I installed an AFR-gauge, ordered a bunch of jets and needles and tuned the QJ
After being done the engine performance and response felt good. As we do not have dragstrips here I decided to put the GS on a chassis dyno again.
He produced 301 PS @ 4460 1/min and 465Nm (342 lbf-ft) @ 4460 1/min. Those numbers are calculated back to the engine already.
So I guess this (at least the power) is in the ballpark of what to expect from a stock Stage1 engine. Not so sure about the torque, though.
EDIT: Double checked with the guy, operating the dyno. He said to not pay attention to the torque, as he was not able to do a proper 4th gear run w/o downshifting. He also said, that the powerfigure is probably on the low side, as most likely the secondaries didn't open completely/slow, as he always tried to prevent downshifts and therefore probably never made a 100% WOT run.
Maybe I will take out my GPS unit and find an empty road to perform some 1/4 mile measurements to back up the dyno results.
What do you guys think?
Its easy to prevent a downshift ......just unplug the switch,...or disconnect the cable,...30 seconds top,....he must not be to familiar with old cars,..nevermind just seen where it was a 200r,...still tho you would just leave it 3rd the 1:1 gear and increase speed to 50mph to prevent downshift
You need to use that leakdown tester on several "known good" engines to see how it reacts. Best if those "known good" engines have similar bore sizes to your Buick.
The "indicated" leakage on the gauge has as much to do with the leakdown tester as it has to do with the actual cylinder leakage. Either your tester has an extremely small orifice between the gauges, or the manufacturer has color-coded the scale too generously, so that worn-out engines still "test" good.
The only ways to know are to take the thing apart to measure the orifice, or to test and compare several engines that AREN'T having problems. Again, best if those engines have Buick-sized bores, and therefore Buick-sized rings. (Stroke doesn't matter.)
150-ish psi cranking compression test results would be perfectly "ordinary" around here. Cranking pressure depends on a dozen or more factors. Compression ratio, cam timing, altitude, and cranking speed being among the most important.
"Good luck" keeping a Turbo Hydramatic 200 of any variety behind a big-block. I know the aftermarket makes heavy-duty parts for them. I still don't trust 'em.
Well this thread was an interesting early morning read.
@ Hugger: There are not many US-Cars around here, and even less Buicks. The guy with the chassis dyno is used to work on "younger" vehicles, mostly BMW.
I did couple of 1/4 mile measurements with my smartphone and an external GPS receiver (same as last year) and also went to the same spot. Performed the test in both directions of the street. Best results for each way was 14:38 @ 95mph and 14:72 @ 90mph. Using several calculators on the net, all leads to about 300 HP @ flywheel, which confirms the dyno number (give and take). Somewhere I have read, that back in the days a magazine tested a stock Stage 1 with 13:43 @ 103.46mph. So my GS lost one second in 50 years; not too bad
@ Schurkey: I am with you in regards to the gauge. I probably was to cheap, when I bought it. If I find time I will do the leakage test again, just out of curiosity. But for the time being I will drive the car as is. Maybe one day I will get into my piggy bank and get an engine from Jim anyway
In regards to the transmission, I certainly hope it will last, as I will not race the car on a regular base.
This is why i had jim at trishield build my new engine... it makes great hp .. if i had a local shop build it and saved $ some how i would holding the short end of the stick
Took the GS out for a cruise today (rural roads 50 to 60 mph). Gas milage improved quite a bit after doing the distributor and the carb. 15.5 mpg is quite good I would think.
Overdrive transmission? 15.5 isn't all that great.
'Course, that does depend on how long you cruised at highway speed, and how long it took you to get to 50--60 mph if there were a lot of stop signs!
Really! ...I thought it exceptional!
I get 11 mpg at best
No overdrive but!
Actually mine was shipped here with the overdrive trans fitted but the guy that brought it in refitted the matching numbers Turbo 400 that was in the trunk.
After kitting it up somewhat
I can understand why.
Gas mileage ain't a worry or I'd be getting round on a Honda Super Cub
I've got nothing directly comparable. Thousands of years ago, I saw 19--20 ish MPG (highway, of course) on a '69 Impala with 350/4bbl and Turbo 400. Those were the years of the NMSL--the hated "55 mph speed limit" on roads designed for 80 mph. So, smaller engine, bigger car, but no overdrive. This was early in the "gasohol" movement, so I had 10% ethanol (or perhaps 5% methanol) in the fuel.
I get 15-ish MPG with my '88 K1500 "350" at 50--60 mph. Smaller engine, overdrive, but also carrying the 4WD equipment around, and horrible aerodynamics.
Closest I have is a 455 in a '66 Toronado--but the rear suspension is so rusty as to be unsafe; it hasn't seen roadway in years and years.
Yepp, Th200-4r along with a 3.23 axle. I am cruising @ 1800 1/min at 60 mph and around 15 AFR.
As always it is a matter of perspective / where you come from . In my case I had times with 8-9 mpg.
Somewhat same here. But when cruising along with my wife next to me, the drag racer attitude stays at home. In this cases it is nice to not excessively burn fuel.
I love the engine sound when the secondaries open, so when driving alone I make sure I do not miss those opportunities. Of course this shows in the mpg I usually see. But no regrets here