i would like a 496 combo that will get my 69 in the 11s . got open and closed chamber big ovals just need a combo .full inter t-350 trans and 373 g s

9.4/1 Static Compression Ratio
Ported 781 Heads with 2.25/1.90 Valves
Isky Z-55 Solid Flat Tappet cam
Edelbrock Performer RPM dual plane intake
Demon 850 mechanical Secondary Carb

This combo made 586HP/600TQ on the dyno, should put you well into the 11's.

Just FYI: others have made considerably more power with roller cams and aftermarket heads.

Which open chamber ovals....049's...781's? Either way, assuming its one of these or something comparable, I agree with all thats been mentioned for a combo, only Id probably use a lunati 402A4 solid. Not that there is anything wrong with the isky, but I think the lunati one should prove to be a little more street friendly yet still plenty capable of getting in the 11's in a big 496 as long as the heads are done well. It would probably even do it with a 3.55 gear with the kinda torque curve youd have to play with! About 10:1 comp is nice too. Talk to Harold about the cam choice if you wanna get the most for yer money.

you didnt mention how fast that combo was I have a 454 30 over in my car now and have the closed chamber s on it with a mild hdro roller and the car runs 13.5 was kinda sad at this 373 grs full int figured it would be faster just want to do it right this time but want to build on the edge this time so any information would help me also limited street use.

I have both 049 and 781s but just dint want to through out all my hdr roller stuff just wanted to use what i could out of old engine the cam is a punk however so will be changing that and using a solid

If your looking to rid yourself of a hyd roller let me know. What kind and specs on the cam are you using now?

Didnt realize you were already running a big block there. Give us more info on that engine. List complete specs on the cam(duration at .050, valve lift, LSA....), what is the actual compression ratio of this current engine, what intake what carb, what headers/exhaust, what castings are those heads and what was actually done to them(if you know). And, what is the stall converter size? Also, whats the timing curve set at(initial and total and what rpm). And finally, post more details about your timelsips. Not only ET, but what was your MPH and your .060 foot times and 1/8 mile et and mph.

Ya never know, the motor you currently have just might be faster than its showing.

454 30 over forged flat tops one valve relef trw .stock rods and crank casting on head is 3872702 and ss valve and pro flo. hydr roller ,herbert 240 250 @50 569 569 and of corse roller hdro roller lifters elda torker 2-0 holly 750 vacuum sec . 15 adv 38 total p295 50d15 hoosier quick time the car is a 1969 full inter 350 trans shift kit with a boss hog con 2600 . 12 bolt with 373 grs . no hop bars and air bag on right rear . hei ign car not spinning just not going fast
60ft 2.0495 330 5.6596 1/8 8.6415 @81.97 1/4 13.4578 @ 101.90

You just need to use whatever heads you want and rework them like you also want, then use .020" steel shims and then order the correct piston to create a right at 9.75 to 10 to 1 CR., for a street gas 496 motor!

AND cc your heads first b/c they do vary from 112/113 to all the way to almost 122!!

My mild 9.8 to 1, 496 with a set of Merlin ovals b/c I was afraid of getting hosed reworking my good -781's, and with just a 750 Holley and a Strip Dom. single plane and 1.75" four tube. long headers per D2K should make right at 550hp at 5500rpm and 580t at 4500 rpm, so I just call it my great big, "tow-truck" grunt motor!

Oh, almost forgot, cam is just an old CC 282S solid and custom ROSS Racing Pistons forged low dome open chambered pistons!! Nothing special at all..

I'm a First Gen. Car guy and I also used the truck rods so I don't really need to rpm mine much above say 5700rpm, imho..

pdq67

it is getting prety nasty around here and got several camaros and novas that want to jump on me so i want to step up there just about all running 1190s so need to get there on engine i did win grudge match last week but cut a good light and used nuks so gonna build a compression engine and want a 496 . would like to use the heads i got but what kind of power with say 13to 1 and the big olvs thanks any help is greatly needed to keep the camaros and novas off me on top now but just lucky right now

I was running high 11's in good air with a .030 over 454,10.5-1,, 049's with 2.19/1.88's no port work, Edelbrock RPM,HP950, 1.75" Dynomax headers, and a Lunati solid .540/.550ish 300/310 233/239ish @ .050 and a B&M converter then ATI 10" converter, which did not improve e.t.'s and th350 with 3.73 gears. I don't like Boss Hogg or Daaco converters, but to each his own. I would at least use TCI or B&M. If you're gonna go to almost 500 cubes, you ought to be shootin for 10's like me :D

That converter may be killing your ET. I had a Boss Hog in my car in my first combo with a TH350 and a sbc 400. My ETs were way off. Car ran 14.00s at 96mph. After I calculated converter slipage I realized it had almost 20% slipage. A good convertor should be at about 6% give or take a % or two. I changed to a different convertor and went 12.70s at 108 mph---with no other changes. The 60ft times where 1.80s with both convertors.

Looking at your ETs and only trapping at 101mph I would say your convertor is slipping pretty bad. a 101 mph is usually around a 14.00 or high 13s. Your running low/mid 13s with only a 2.0 something 60ft. Your numbers dont jive.

I used to sell those Boss Hogs through my shop. I,ve had more than one problem with them. Not trying to bash a company here, it is just I have had some bad luck with them. I wont touch them.


What is your tire size, trap RPM, gear ratio and trap speed? With that info you can calulate your slipage.


BTW, I have a 505 in the car now, runs 11.50s all day every day through the exhaust, 3.73s, TH400, 3000 stall Coan convertor. Drive it to the track and home. Very doctile street car.

Your engine has the potential to be way faster than mid 13's. Personally, Id ditch the converter for a something of a higher quality, get rid of the torquer intake for a performer rpm, and try out a mechanical secondary carb. Also, check out the valvetrain real good with that hydro roller cam, and if you dont have headwork done, get some done to those heads. With that motor, if everything was on track I dont see why you cant run low 12's as is if not faster.

One of the big issue is your current compression with the flat tops. Id say its at 9:1 at best and probably lower. Youd need .040 quench and about a 6cc dome piston to make 10:1 comp. Thats another one of the issues. Am I correct that you dont have the 3.73 gears yet but you plan to get em...or did I misread? Also, what is your tire height and engine rpm when crossing the finish line during those runs?

Well, the choice is yours...you can either revamp the current setup or continue with the plans for the big motor. If so, youve got plenty of combos listed that will go 11's easy. Here is something that might be worth considering though. Being that is all big blocks, get another intake and carb anyways and throw it on the current engine along with a good converter and see how she does. That alone might float your boat pretty good, and if your not impressed, reuse the stuff for the better motor. The only real problem with doing things this way will be the converter. Even if you buy the best converter in the world, if its optimial for the current 454, its not gonna be right on track with the new engine(the 496) cause it will act differently behind both motors, and it might not act right behind the 496 if its specd for the 454. Anyways, reguardless of what you build, redo yours or go all out(the 496 gets my vote hehe) that intake and converter got to go for sure and the 750 vacuum secondary carb is a little on the small side for a healthy 496.

you can bet im gonna change the converter the car already has 373s in rear and I know i need more carb but dont know what intake want to run an open intake cause i got a plate system on it tires are p295/50 d15 hoosier q-times and abought 6500 through trapps

Wow,
Sounds like you have a decent combo, but something is amiss big time. That setup ought to go easy mid 12's.
The 60ft is a clue.......you have no power. Ditto for the mph.
Some things to check.
Is the carb opening all the way when you floor it?
Are the secondaries working?
Is the fuel system up to snuff?
Is the trans slipping?
Do you have headers?
At least a 2.5" exhaust? Preferably 3".
Are you sure the cam is installed correctly? Not one toof off?
The converter is suspect....don't know a thing about what you have, but even a TCI or B&M street strip unit is a good upgrade.
If you have closed chamber heads, with flat tops, the CR is maybe a bit low, around 9:1 like Greg said, but not that big a deal. If you have open chambers with flat tops, then you have less than 8:1.
The intake isn't the best, but will work.
Before jumping on the 496 band wagon, you need to get what you have running correctly, it should surprise you.
Ron

2 1/8 is header size and 3" through flow masters cam and all is right but just cant figur it out built a few years ago havent driven much are tinkered with it but the roller stuff tapped me and thats why the converter was of such high Q ha but can upgrade just neet to know what works

OK, with a trap speed of 6500 that you posted
Mph of 101
tires 26.6 inches tall
gear ratio of 3.73

That calculates to 26.7 % slipage :eek: :eek: :eek:

that = serious convertor or trans problems. I wouldnt even think about the engine untill you get the slippage issuses solved. More power will just make it worse.

For compairason, my car goes through the traps at 5700rpm, 119mph with 28" tires and 3.73 gears. That = to 6.5% slipage.

Here is the link if you want to check it yourself. http://www.wallaceracing.com/converter-slip.php

yea sounds funky . I dont think it is the trans its fresh but i will for sure change the converter who makes a good converter that i can afford around 300 bucks 3000 to 3500 allso ran a 60f 1.9193 1/4 12.24 @ 111.66 on a 150 shot the same night would like to get every thing right however

My son is running my old motor right now, he has run a best of 12.24@108 on slicks n/a with no suspension work, he hit it with a 125 shot and ran a 9.30 @111 1000ft time, slick tired cars are supposed to be limited to 1000ft at one of the tracks I run at. He then snuck in with the street tired cars and ran a 9.50 1000ft, 11.32@116mph running out of nitrous. He is using a 10-11" Neal Chance converter he picked up from 40Coupe for a decent price. I think you can sneak into the low end ATI converters for around 300.00. Check it out www.atiperformance.com , give em a call, costs nothing. I have had good luck with B&M converters too, I've run two of their 11" converters into the 11 second range.

what size wheel and back spacing allso what size slick man that thing hooks what converter is in it

I'm using an ATI 10" converter, stalled 3500 behind the old motor, around 3800 behind the 505. I still drive it on the street. I'm using 15x8 draglites with 4.5 backspacing 30x9x15 Hoosier radial slicks for the time being, a bit pricey though. 1.51-1.52 60ft times were with 3.73 gears, running 4.11's now, put my air bag back in the right rear, hoping to break into the 1.4x in better air...

Check out coan converters as well. They make very good stuff and currently have a 10 inch competition converter on special sale for 375 bucks....you will have to talk to them about what the stall speed would be. Another thing that sorta grabs me the wrong way is the headers.......those header tubes are a little unnecessarily large......2 inch at the most would be better and Id personally have went a little smaller yet on the header tube diameter....thats just me though. There are definitely some bugs in your current setup that could be worked with and like I was sayin before, you should be capable of being much much faster than you are.