Am I on the right track? SB question

Posted By: Kevins493

Am I on the right track? SB question - 08/07/11 08:16 PM

I've been threatening to do this for a long time, finally getting tired of my street car not being able to get out of its own way. The car in question is a '73 challenger, weighs 3650 with driver (full interior street car). What's it going to take to get this heavy pig in the mid 12s at 550' track altitude?

Here's what i've come up with so far:
360 10:1 with stock crank and rods with arp rod bolts
home ported 2.02 x or j heads (i'm 22 and on a budget)
hydro cam with duration at .050 in the mid 240's, haven't decided on actual cam yet..Hopefully I can make the power brakes work with that much duration. Will most likely use stock stamped rockers.
performer rpm intake with a 3310 holley carb
most likely using 1 5/8 headers that are on the car.
727, I have a ptc 10" converter that flashes a little over 3000, may need more. I want to have decent street manners though.
3.91 rear with a 275/60 drag radial.
Am I on the right track?
Also I've never built a non-stock cast crank motor before, what am I going to be looking at to balance it? I'm assuming it would stay external.

Posted By: goldmember

Re: Am I on the right track? SB question - 08/07/11 08:48 PM

Mid 12's doesn't need much to get there. I'd run a shorter cam duration than mid 240's in a hyd. Call Tim @Bullet for a good hyd cam. Low 230's .480ish 108lsa is fine for this combo and won't need anything special to make it work.You don't need to internally balance this either. Just keep it simple. Quality machine work,good valve job,etc.

Posted By: Crizila

Re: Am I on the right track? SB question - 08/07/11 09:05 PM

Quote:

Mid 12's doesn't need much to get there. I'd run a shorter cam duration than mid 240's in a hyd. Call Tim @Bullet for a good hyd cam. Low 230's .480ish 108lsa is fine for this combo and won't need anything special to make it work.You don't need to internally balance this either. Just keep it simple. Quality machine work,good valve job,etc.

You should just about be there with what you mentioned.

Posted By: justinp61

Re: Am I on the right track? SB question - 08/07/11 09:14 PM

I'd say the what you have picked out should go mid 12s with out any trouble. I don't know about the stamped rockers with a cam that size and the springs that it will take to keep everything under control. Power brakes may require a vacuum pump though. My 340 had a 237/242 @ .050 .588/.592 lift with 1.6 rockers, hydraulic. With ported Edelbrocks it went mid 7.20/ 11.50s in a 3300# Dart. I'd look at a Weiand X-Celerator, a very good intake on 340/360 engines IMHO.

Posted By: MR_P_BODY

Re: Am I on the right track? SB question - 08/07/11 09:38 PM

I would use a cam with 110 - 112 LSA so your brakes
work and it will idle nice

Posted By: tubtar

Re: Am I on the right track? SB question - 08/08/11 01:57 AM

I had stamped rockers fail on a 230* .480 ish hydraulic with not a ton of spring either.
The push rod punched through , so I would give thought to using a H.D. stamped rocker at a minimum.
I never had that combo at the track , but seat of the pants it felt quicker than a previous mid 12 second ride I had , so you will be pretty close with that set up.

Posted By: Kevins493

Re: Am I on the right track? SB question - 08/08/11 05:24 AM

I forgot to mention that it has really restrictive 2.5" exhaust on it. The 440 picked up 3 tenths uncapped when i ran that. I have a '73 340 in it now with 8.1:1 compression not accounting for valve reliefs. It has the xe-268 cam (110 lsa, 224(?)duration at .050, .477/480 lift) but the compression is just killing it.
I was actually thinking of going with at least a 110 lsa because I know that helped with cylinder pressure on the 493 in the car in my sig by raising the cylinder pressure and such.
Will that converter be ok to reach the target et?
I will probably end up putting the HD rockers or a set of ductile ones on it.
Thanks!

Posted By: MR_P_BODY

Re: Am I on the right track? SB question - 08/08/11 05:36 AM

Quote:

I forgot to mention that it has really restrictive 2.5" exhaust on it. The 440 picked up 3 tenths uncapped when i ran that. I have a '73 340 in it now with 8.1:1 compression not accounting for valve reliefs. It has the xe-268 cam (110 lsa, 224(?)duration at .050, .477/480 lift) but the compression is just killing it.
I was actually thinking of going with at least a 110 lsa because I know that helped with cylinder pressure on the 493 in the car in my sig by raising the cylinder pressure and such.
Will that converter be ok to reach the target et?
I will probably end up putting the HD rockers or a set of ductile ones on it.
Thanks!

Your gonna need to up the compression

Posted By: Triple Threat

Re: Am I on the right track? SB question - 08/08/11 05:37 AM

My combo is .030 over 340,
low compression, stock rotating assembly, cast piston
63cc eddies OOTB ~ 9:1 compression
230/230 @.050 480/480 lift hydraulic
stock rockers
Air gap intake
4150 750 holley
1 5/8-3/4 step TTI's
904, 9.5" ptc 4600 flash
8 3/4 with 3.91's and a 26" tire or the new dana with 4.10's and a 27" tire.

~3500 pounds with the stereo system and such. This is a full weight street car that I drive to work, take girls on dates in ETC. Its got roughly 1,000 passes on it now not including street miles and abuse.

Best pass in the car is 12.29@107.5 Normally in the 12.50 zone.

Posted By: Paul_Fancsali

Re: Am I on the right track? SB question - 08/08/11 09:33 PM

Give it a load of total timing get it up into the 40s total with no vac advance. That engine should take close to 43-44 total and see if it runs better. That enegine is closer to 7.5 then it is to 8.5 to one if parts are stock

Posted By: thedriver

Re: Am I on the right track? SB question - 08/09/11 06:13 AM

12s won't be fast enough, just sayin! Buy the stroker now. Pay now or pay later.

Posted By: Kevins493

Re: Am I on the right track? SB question - 08/09/11 07:42 AM

Quote:

My combo is .030 over 340,
low compression, stock rotating assembly, cast piston
63cc eddies OOTB ~ 9:1 compression
230/230 @.050 480/480 lift hydraulic
stock rockers
Air gap intake
4150 750 holley
1 5/8-3/4 step TTI's
904, 9.5" ptc 4600 flash
8 3/4 with 3.91's and a 26" tire or the new dana with 4.10's and a 27" tire.

~3500 pounds with the stereo system and such. This is a full weight street car that I drive to work, take girls on dates in ETC. Its got roughly 1,000 passes on it now not including street miles and abuse.

Best pass in the car is [Email]12.29@107.5[/Email] Normally in the 12.50 zone.

That sounds a lot like my junk except for the heads and converter. Ran a best of 14.40s with that motor and 3.91's and a short tire. Do the new RHS heads flow about the same as the eddy's? I know i'm going to want to build a better short block at some point just for peace of mind but throwing a set of closed chamber heads on it would be cheaper.

Mike, you're an engineer right? I took thermodynamics last semester and that really opened my eyes to how compression affects performance. That's a big part of the reason for this build.

As far as the stroker, this is just my street car that I've had since I was 15. I just want to get to the point of enjoying the car again. And after selling the Fury to BobK i kinda miss a fast street car. If I want to go faster I have the Polara in my sig.

i'll admit my knowledge of big blocks far outstrips my knowledge of small blocks but right now keeping the sb makes sense.

Posted By: Kevins493

Re: Am I on the right track? SB question - 08/09/11 07:43 AM

Quote:

Give it a load of total timing get it up into the 40s total with no vac advance. That engine should take close to 43-44 total and see if it runs better. That enegine is closer to 7.5 then it is to 8.5 to one if parts are stock

Wow that's a lot of timing. Could almost make a nitro motor happy

but i've heard of the Stock guys running it that high.

Posted By: Triple Threat

Re: Am I on the right track? SB question - 08/10/11 05:55 AM

Quote:

That sounds a lot like my junk except for the heads and converter.

Those are the 2 pieces that make my combo. The car with 2.02 iron heads ran 13.80's @98, Did the head swap and with no other changes the car went 12.80's @106.

The converter cost me about 1 mph, but dropped the ET by about 3 tenths.

If you buy the RHS heads prepped by IMM, they will outflow an OOTB eddy by quite a bit. They're heavier but probably better buy IMO that an Edelbrock. Also check out the EQ heads (Performance only sells them I think), they are supposed to be a good economical piece as well.

Posted By: Kevins493

Re: Am I on the right track? SB question - 08/11/11 06:16 AM

Thanks Dustin!
A second is pretty impressive for essentially just bolting on a set of heads. What converter did you start with? I'm probably swapping my 3200 ptc in this week because the piston seal for the front clutch pack came apart, it won't stay in high gear anymore. I put compressed air to the port on the case and it had about 100% blowby.
I will definitely look into IMM's stuff as well as the EQ heads.

Posted By: Triple Threat

Re: Am I on the right track? SB question - 08/11/11 03:06 PM

10" Hughes ~3000 stall. The car went from 1.85 to 1.68 60 foot with the converter swap.

PM me anytime if you got more questions.

Posted By: Kevins493

Re: Am I on the right track? SB question - 08/12/11 07:26 AM

Thanks!