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Well olds gang here goes finally after 2 years we made the change over this year and got down there yesterday 9/22/19 to rock falls raceway, were to start here goes, the car ran consistent 13.44 13.45 best 13.34 at 100.22 with the 3.31 in it, 60 foot times were 1.85 to 1.90 With the 3.91 in it yesterday first run 13.75 at 98.75 2nd run 13.85 at 98.95 3rd run 13.71 at 99.22 first round elimination 13.71 at 99.28 second round elimination 13.67 at 99.69 final round 13.65 99.92 60 foot times were 2.010 2.100 with the 3.31 i use to cross at 4500 rpm with the 3.91 it was 5000 rpm i had on a brand new set of 28/9/15 hossier slicks, my brother was watching no wheel spin !! i was shifting the car at 5000 rpm it was really done there i went to 5200 that's when it ran that 13.85 iam not an expert on this but long long time ago we had a 67 442 that had 3.90 in it its like the motor cant rev that fast so we put 3.55 in it and got its torque back went like a bat out of you know what !! that 455 motor back then was a stock 1970 455 4bbl out of a 98 no work done to it, no special converter no nothing, i have a 488/496 lift 260/268 duration cam a 2600-2800 coen converter 3x2 bbl i wasn't looking to set the track record but a couple of tenths and 2 miles an hour would of been nice, i just thought this would be the ticket looks like i was wrong, anyway we had a great time !! i would like to hear some of the olds gangs opinion on all this cuz iam left with a big i just don't get it, thanks guys john !!!!!
Last edited by john mann; Sep 29, 2019 at 06:12 AM.
Well olds gang here goes finally after 2 years we made the change over this year and got down there yesterday 9/22/19 to rock falls raceway, were to start here goes, the car ran consistent 13.44 13.45 best 13.34 at 100.22 with the 3.31 in it, 60 foot times were 1.85 to 1.90 With the 3.91 in it yesterday first run 13.75 at 98.75 2nd run 13.85 at 98.95 3rd run 13.71 at 99.22 first round elimination 13.71 at 99.28 second round elimination 13.67 at 99.69 final round 13.65 99.92 60 foot times were 2.010 2.100 with the 3.31 i use to cross at 4500 rpm with the 3.91 it was 5000 rpm i had on a brand new set of 28/9/15 hossier slicks, my brother was watching no wheel spin !! i was shifting the car at 5000 rpm it was really done there i went to 5200 that's when it ran that 13.85 iam not an expert on this but long long time ago we had a 67 442 that had 3.90 in it its like the motor cant rev that fast so we put 3.55 in it and got its torque back went like a bat out of you know what !! that 455 motor back then was a stock 455 4bbl out of a 98 no work done to it, no special converter no nothing, i have a 488/496 lift 260/268 duration cam a 2800 converter 3x2 bbl i wasn't looking to set the track record but a couple of tenths and 2 miles an hour would of been nice, i just thought this would be the ticket looks like i was wrong, anyway we had a great time !! i wold like to hear some of the olds gangs opinion on all this cuz iam left with a big i just don't get it, thanks guys john !!!!!
John, what was the temp yesterday ? Did you get the "mold release" burned off the tires ? That cam is something to use in a "grocery getter". You need at least 285/287 degrees. The converter is more than you need. You could be running the factory 308/308 cam with that stall.
Hi Ralp, it was 67 deg out there, the converter i got was from craig hes there big wig at coen converters, he asked for all my info on the car and said this is the one for me, i think it works pretty good no problems with it.. Slicks worked great... john....
This is exactly why I always post about the importance were peak HP is made, and power carry. More RPM means more gear, more converter, quicker quarter mile times. So now it looks like a cam and valve spring change is in order to take advantage of your new combination. My cam grinder can grind you a hyd flat tappet that is dimensionally perfect in every way and he has perfect track record with zero problems, he also supplies the modified lifters. He is simply the best, if I can help let me know.
Last edited by VORTECPRO; Sep 23, 2019 at 07:56 PM.
Well olds gang here goes finally after 2 years we made the change over this year and got down there yesterday 9/22/19 to rock falls raceway, were to start here goes, the car ran consistent 13.44 13.45 best 13.34 at 100.22 with the 3.31 in it, 60 foot times were 1.85 to 1.90 With the 3.91 in it yesterday first run 13.75 at 98.75 2nd run 13.85 at 98.95 3rd run 13.71 at 99.22 first round elimination 13.71 at 99.28 second round elimination 13.67 at 99.69 final round 13.65 99.92 60 foot times were 2.010 2.100 with the 3.31 i use to cross at 4500 rpm with the 3.91 it was 5000 rpm i had on a brand new set of 28/9/15 hossier slicks, my brother was watching no wheel spin !! i was shifting the car at 5000 rpm it was really done there i went to 5200 that's when it ran that 13.85 iam not an expert on this but long long time ago we had a 67 442 that had 3.90 in it its like the motor cant rev that fast so we put 3.55 in it and got its torque back went like a bat out of you know what !! that 455 motor back then was a stock 455 4bbl out of a 98 no work done to it, no special converter no nothing, i have a 488/496 lift 260/268 duration cam a 2800 converter 3x2 bbl i wasn't looking to set the track record but a couple of tenths and 2 miles an hour would of been nice, i just thought this would be the ticket looks like i was wrong, anyway we had a great time !! i wold like to hear some of the olds gangs opinion on all this cuz iam left with a big i just don't get it, thanks guys john !!!!!
John let me see if I can sort this out. The cam is advertised degrees duration ? Is this correct ? w/3.31 gears: 13.44, 13.45.... best 13.34 @ 100.22 mph 60 foot times: 1.85 to 1.90, Trap rpm: 4,500, stock 455, converter, 3 X 2, stock Olds 98 cam, 26" tall tire w/3.91 gears: 13.75, 13.85,13.71, 13.67,.... best 13.65 @ 99.92 mph 60 foot times: 2.010, 2.100, Trap rpm: 5,000, 455, 2800 converter, 3 X 2, cam: 260/268, .488/.496, 28" tall tire
Last edited by OLDSter Ralph; Sep 25, 2019 at 01:16 AM.
Reason: add. info
Ralph, its the JM 18-20 engle cam, valve lift in 488 ex 496 running duration in 260 ex 266 duration at .050 in 216 ex 226 everything correct on top but the 3x2 was on both engines hope this helps, 2600-2800 stall, thanks john..
By ALL accounts... the new gears should net quicker times.
I think there’s something that changed.
2 years is a Looooooooong time to do a back to back test.
There’s timing, plugs, wires and carb that I guarantee could have been fiddled with during that 2 year period OR could have simply grown a bit tired resulting in a slower ET.
Maybe a vacuum leak developed?
Somethings amiss here. Get your car back to the track with a timing light and play around.
-pete
Ralph, its the JM 18-20 engle cam, valve lift in 488 ex 496 running duration in 260 ex 266 duration at .050 in 216 ex 226 everything correct on top but the 3x2 was on both engines hope this helps, 2600-2800 stall, thanks john..
John, how did you choose that cam? The duration sounds very similar to a cam used in an Olds 98. You have more lift, but its dead at 5,000 rpms.
By ALL accounts... the new gears should net quicker times.
I think there’s something that changed.
2 years is a Looooooooong time to do a back to back test.
There’s timing, plugs, wires and carb that I guarantee could have been fiddled with during that 2 year period OR could have simply grown a bit tired resulting in a slower ET.
Maybe a vacuum leak developed?
Somethings amiss here. Get your car back to the track with a timing light and play around.
-pete
By ALL accounts... the new gears should net quicker times. I think there’s something that changed.
2 years is a Looooooooong time to do a back to back test.
There’s timing, plugs, wires and carb that I guarantee could have been fiddled with during that 2 year period OR could have simply grown a bit tired resulting in a slower ET. Maybe a vacuum leak developed?
Somethings amiss here. Get your car back to the track with a timing light and play around. -pete
I tried to summarize things in post #5. I think the rear tires were also changed.
Ralph !! in post 5 i had the mondello cam in both engines listed jm-18-20 i bought the cam from mondello before years ago in that other 67 442 that i had.. sorry ralph i installed the cam about a year after i put that 98 engine in there, so yes at the end of the day both engines were pretty much the same.. and yes you are correct, with the 331 i used the 26/10/15 hoosier slicks, with the 3.91 i use hoosier also but they are 28/9/15 they are 2 " taller like i just posted to Pete i think that may of hurt a little bit ?? so is the camshaft my problem not enough duration ?? john,,,,
Last edited by john mann; Sep 24, 2019 at 05:56 PM.
there is lots of little tricks you can do. One I always tell people. back when my little near stock 350 was stuck running 14.0 . I added an X pipe and ran a 13.87 through the mufflers vs a 14.0 with open headers , Another thing to consider is the gear will affect Your over all RPM and will affect the stall speed. Just fwiw .
Someone mentioned lfiter preload. I always ran my ( commonly called) " valve lash" which on a hyd cam is lifter preload to half turn so about .040 lifter preload. I backed it up to 1/8 so about .010 based off thread pitch to its respective thread diameter. The engine totally changed. It reved much faster and produced more power.and it showed In the MPH
ON my current engine an air pan to feed the engine fresh air ( ram air ) was worth 2 mph.
Last edited by coppercutlass; Sep 24, 2019 at 07:47 PM.
with the 331 i used the 26/10/15 hoosier slicks, with the 3.91 i use hoosier also but they are 28/9/15 they are 2 " taller like i just posted to Pete i think that may of hurt a little bit ??
Bingo ! you solved your problem.
Adding the larger heavier tire worked against you 3 ways.
1) The 28 inch tall tire effectively turned your 3.91 into 3.63.
2) You added somewhere around 3 lbs of weight to each rear wheel, assuming you used same rims as last time.
3) Additional wheel weight is unsprung weight, unsprung effect magnifies the additional weight.
https://www.caranddriver.com/feature...-wheels-tires/ this page details the negative impact of using heavier wheels while staying the same outside diameter. Now imagine how bad the results would of been for Car&Driver had they also added 2 inches in tire height.
28 inches is base height for gear ratios i thought ? I went from a 3.73 with a 26 inch tall tires to a 3.90 with a 28 in tall tire with no change. I did that on pourpose.
As far as weight. I know it affects it but I went from a much heavier aluminum wheel and drag radial combo to a lighter aluminum wheel with bias ply tires and tubes with no change in Mph. People always claim the bias ply slows you down but i didnt see it.
Last edited by coppercutlass; Sep 25, 2019 at 06:47 AM.
I went from a 3.73 with a 26 inch tall tires to a 3.90 with a 28 in tall tire with no change.
I'm gonna say your car had not found its sweet spot yet. On the other hand i think Johns car just about peaked as is prior to gear swap. His 100 mph trap speed is indicative of 1966 -1972 W30 performance when bone stock give or take. Now put a 28 inch tall tire with same grip as stock on any of those cars that have already ran a "perfect pass". With no other modification whatsoever and i say they all slow down a little...
Originally Posted by coppercutlass
As far as weight. I know it affects it but I went from a much heavier aluminum wheel and drag radial combo to a lighter aluminum wheel with bias ply tires and tubes with no change in Mph.
You have a more aggressive car in my opinion that was still finding itself. I think he would need to add HP in order to see the benefit of up-sized tires.
For example, put headers and adjust tune accordingly on a 1966 W30 and its gonna probably need 28 inch slicks to see its true potential.
The taller tire usually carry's more MPH. He went up in gear with a taller tire. I bet if he changed the timing curve to help spin the engine faster that gear will come to life. I went from a 3.42 to a 3.73 in a near stock set up and saw a significant change in 60 ft. And no change in MPH but the e/t was lower. That was when going to an x pipe helped me cross from a 14.0 to an 13.86. Also a harder biting tire will slow down a car. If you are after lower E/T cutting the 60 ft. Is everything. Thw difference between my car running an 11.90 and an 12 0 is i need a 60 ft. Isn the 1.62 to 1.63 range to get an 11.9 if i click off a 1.65 its gonna be a 12.0 e/t with MPH about the same in the 110 mph range. Just fwiw
Phil 69CSHC.. And to everybody who has came to bat for me i had this idea about a 3.91 like i said about 2 years ago it just took me a while to find a axle and then i sent it in to have it done finally thru trial and error most of you on here now helped me thru errors that lord knows i have had many, but thanks to the great people on this site i got everything taken care of and finally last weekend got to give it a go !! i seen this road test in my muscle machines July of 2019 on a 1970 w30 with a 3.42 that turned 14.36 at 100.22 then with a 3.91 it turned 13.98 at 100.78 so i thought hopefully i could get a couple of tenths and maybe 2 mph Phil 69CSHC just today 3 days after the track i myself stated thinking you know i think the olds was all in with the 331 i believe if it had the 3,42 olds axle in it maybe a best run of 13.30 at 100.50 a little bit better that my best of 13.34 100.22 i do believe that was the sweet spot right where we were because of the trap speed of 100.00 so i will look around over this winter for a set of GM olds 3.42 iam going to keep the 3.91 in it for now and play around with it a little bit to get back to the mid 13.50 its pretty close !! iam still more than happy with it, i have some 255/60/15 mickey thompson ET drag radials that are 27" tall one inch shorter that my 28" hoosier that i raced with, that may get me where i would like to be, iam going to post some pics of our car so you guys can see it, thanks again to everybody above glad you gave me your opinion ken also and coppercutlass the whole olds gang !!! john .........
Last edited by john mann; Sep 25, 2019 at 02:55 PM.
Beautiful car John, your current performance is my dream performance. I have always viewed 100 mph in the 1/4 as ideal.
Originally Posted by coppercutlass
I bet if he changed the timing curve to help spin the engine faster that gear will come to life. I went from a 3.42 to a 3.73 in a near stock set up and saw a significant change in 60 ft. And no change in MPH but the e/t was lower. That was when going to an x pipe helped me cross from a 14.0 to an 13.86.
Good stuff copper, i defer to you here. I have 10 years on and off of track time but always with a stockish Olds. Never been under 15 seconds and never seen 90 mph. I have played around with wheel weight, size, etc. As well as other small changes here and there. After that very limited especially under the hood.
PS I am about to open a new thread here in Racing and high performance. Would really appreciate if you, John, Ralph, as well as others chime in. (you have mentioned that x pipe before I am starting to seriously think about trying it although my car is so stock the gain will probably be a fraction of yours)
The x pipe showed gains with a near stock set up. Current engine does not like it. I have had 4 different combinations over the last 10 years. Baby steps lol. I learned alot as i went. Also beautiful car John
It sounds like you are going to be racing this car a decent amount. I would recommend getting that RV cam out of there, as you aren’t pulling a boat with it, and it’s not an RV.
We ran that exact 18-20 cam in a mild 455 and the best time we ever ran was a 13.70 in a 4,000 lb car on 26inch drag radials, 3.42 gears, and a 2200 converter. Our engine was also done by 5,000rpm. We pulled a heavy trailer with that car, basically using it like a truck. Not saying we couldn’t have shaved a few tenths off of it, but that was pretty well “power-tuned”.
I would contact Vortecpro about a good cam grind to better work with your combo instead of spending lots of money on little items to whittle away on the car a tenth at a time. The right cam and converter could make it a whole different car, and then you could whittle away to get it into the 11’s.
Doing some effective intake porting and head porting/increased valve sizes/development would also net some good gains with a better cam.
Keep it up and don’t be discouraged!
Last edited by Battenrunner; Sep 26, 2019 at 11:49 PM.
The only thing i would say is that chipping a few tenths adds up and its stuff that would have needed to be done anyway to make power. My last set up I wemt from a 12.90 to a 12.22 without major changes to my set up. Just lots of little things that didnt cost a whole lot.
Probably enough wiggle room for a 13.0 considering the MPH. And the earlier runs. But the fact it (gained) E/T means it needs some for of tuning to take advantage of the new gear.
Last edited by coppercutlass; Sep 27, 2019 at 09:31 AM.
A 28" tire is a lot for your HP level. You now have more tire but a slower 60' time with no wheel spin.
Typically .1 off your 60ft will give you about .2 in the quarter. You did it in the opposite direction.
I would have expected you to pick up at least .1-.2 in the 60 ft. with the gears.
The peak MPH was nearly the same so I would say you are making similar power as before.
You need to try the smaller tires for a valid comparison.
Lonnie, makes sense to me, the only problem those 26/10/15 were shot with the gear change going from the 3.31 to 3.91 i just figured i would need the taller tire the 28" slicks that i bought, thanks for your input. john..
I'm considering putting 28's on my '66, but it has 4.33's & I'll probably lose some performance, but I need to reduce the highway RPM some.
After seeing your wheels, I'm really considering a set of the SS1 wheels for my car.
A 28" tire has approximately 7% more rotational inertia than a 26" tire with the same weight due to the larger radius from the center line of the wheel & a large portion of the tire weight is at the outer tread area. You would have to reduce the weight of the 28" tire by approx 2lb to to offset the larger rotational inertia, plus correct for the gearing disadvantage.
Last edited by Lonnies Performance; Sep 27, 2019 at 06:53 PM.
Just FWIW. A close friend of mine went from a 28 in. Tall drag radial on a heavy steel rim ( front steel too ) to lightweight cragar super tricks in the front and a short tire in the back 26 in. Car didnt change one bit. Im not gonna argue theory but i will say that some of these changes can be more dependant on combination. Another good friend of mine looses 2 tenths between a shorter heavier bias ply tire vs his talled drag radial. In his situation the drag radial is lighter as his wheek combo is lighter vs the older heavier aluminum rims and the bias ply and tubes. I have played the tire flip game betwee n 26 inch and 28 inch and didnt see any significant changes. I did those with a gear change much like the OP. I went from a 3.73 with a 26 in tall drag radial to a 3.90 with a 28 in drag radial. No change in anything just fwiw.
I went back and looked at my logs. Here is exactly how it went. I actually mixed it up. Our fastes pass. With the 3.73 gear and a 26 inch tall tire was a 12.63 @ 105.5 with a 1.830 60ft. It was a nice cool October night. Keep that as a baseline.
I went to a 3.90 that winter and our first time out was a hot day muggy and mid 80's . but it went as followed. 12.77 @ 105.1 with a 1.78 60 ft. This was with a 3.90 and a 26 inch tall tire.
Best pass first time out with the nittos (28 inch tall) was. 12.55 with a 1.80 60 ft. @ 106.35 mph. It was a nice september day. Keep in mind I went from a 750 Vac. Secondaries to a double pumper 750 this time out. But notice the variances in 60 ft. And mph. Pretty minor. The carb change netted me some HP so the jump in Mph was probably from that.
Then our very best pass on a nice November cool day with the 3.90 and 28 inch tall tire on the same combo was a 12.45 @ 106.56 with a 1.75 60 ft. .
Hope that helps . I do appologize for my mix up but despite the carb change things stayed pretty consistent. The 60 ft. Never made any big jumps and the MPH didnt change a whole lot between previous passes and with the gear change and carb change. So if you compare my fastest pass with the 3.73 and the shorter tires
Vs the 3.90 and taller tires with even a carb change the difference is .08 in 60 ft. And 1 mph. In similar weather for both those passes
As a side note that same combo with a little suspension work and a 150 lb weight loss for the car. It went. 12.29 @ 107.3 mph with a 1.71 60 ft.
Last edited by coppercutlass; Sep 28, 2019 at 08:45 PM.
1. Your first pass with 3.90's & 26" tire had a slightly better 60' as expected from the gearing advantage, but the hot muggy weather likely took some power away.
2. Your passes with 28" tires could have been from the DP carb breathing better... remember the vac secondary carb looks for a certain velocity through the primaries to open the secondaries & it likely was not fully wide open on your engine. Also we are comparing to your first data point which was a previous best pass.
Making 2 changes at a time is always hard to diagnose... did 1 help & 1 hurt, or did both improve things?
3. Finally your best pass on a cool day was the best time with the best 60' time & also highest MPH.
Looking at this vs. #2 above, you gained about .05 in the 60' & about .1 overall.... this is a consistent result.
It is conceivable the your tires slowed you down & the carb was more responsible for the improvements...
I would like to see you take both sets of tires to the track & compare back to back passes.
It is cool to analyze the results.
Regardless, as you said there was not a huge difference in any of the times.
Cars with a healthy stall converter & good torque will not be effected as much as a lower powered vehicle.
Your lightened results gave you a .16 benefit which is consistent with a 150lb weight reduction (.1 per 100lb. is expected on an average 3-4000 lb car).
Yup. I know the lbs per e/t drop ratio. again I know I should have done one change at a time but there was enough consistency to where it wasn't a huge factor in differences. It was close enough to where you could use this as a good comparison. Again that's just my experience.
What has been done to the engine?
Is it a 400 E ?
Does the car see lots of street miles?
There are two very fast 400 E cars on the forum they are long time racers have you spoken to them?
Last edited by Bernhard; Sep 30, 2019 at 09:22 AM.
