Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Sat Aug 23, 2025 8:04 am

All times are UTC-07:00




Post new topic  Reply to topic  [ 8 posts ] 
Author Message
 Post subject: Slant 250 Nitrous Shot
PostPosted: Mon Aug 04, 2025 12:54 pm 
Offline
1 BBL (New)

Joined: Sat Aug 02, 2025 9:53 pm
Posts: 4
Car Model: Dart
Hello everyone, i need some help on my slant build. I am going to put Nitrous through it. It will be a 250 shot, below are the parts I am going to buy and build it with. Are these parts going to hold up for drag racing only? I am not looking to run Nitrous on the street. I also will be running a Nitrous progressive controller for a 75 shot out of the line and at 60ft crank it up to 250. If it is on the verge of blowing up let me know as im trying to minimize it as much as possible but know the risk of a 250 shot on a slant.

-Wisco forged pistons
-Holley 2 barrel 500cfm carb
-Stock rods
-Forged stock crank
-Progressive Nitrous controller in 2 steps 75 shot at launch at 60ft run the full 250 shot
-Stock distrubitor with petronix kit, will retard timing based on the rule of Nitrous
-Copper head gasket
-Stock head just cleaned up with new seals
-a Nitrous cam with matching springs from comp (Don't know what yet probally custom grind from one of the prior forum posts)
-arp head studs
-Zoomie headers
-Plate style not fogger Nitrous setup. With a good fuel pump that will supply enough fuel to support any Nitrous i want to throw at it.
-Aussie speed intake

What do ya"ll think will the pistons see mars? If not should I go more Nitrous 😅


Top
   
PostPosted: Mon Aug 04, 2025 2:27 pm 
Offline
SL6 Racer & Moderator
User avatar

Joined: Sat Oct 19, 2002 12:06 pm
Posts: 8948
Location: Silver Springs, Fl.
Car Model:
The biggest problem I see is using a plate system. I personally think that you will not get many runs without breaking something, with a plate. If you are serious about this build, spend the extra money for a "fogger" system. I always ran better, and had fewer problems with the "fogger".
Why only a 60 shot off the line? I was launching my Cuda on the bottle. Any where from 150 to 200 shot, depending on whether I was looking to go rounds, or set a record.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225


Top
   
PostPosted: Tue Aug 05, 2025 1:18 pm 
Offline
1 BBL (New)

Joined: Sat Aug 02, 2025 9:53 pm
Posts: 4
Car Model: Dart
Charrlie_S the 75 shot of line is due to a lincoln logger 7.25 rear end. Trying to keep reciprocating weight down to a minimum. But thats also a theory shot. Unknown exactly what shot I can do off the line. Also we're you using stock pistons on yours? Unfourtantly weisco is sold out and its going to be good 8 weeks before they can make them. I am on a time restraint. Also really don't want to drill holes in my aussie speed intake and the tuning involved with a fogger system first time nitrous user here. Where is the failure on the plate system is it distribution?


Top
   
PostPosted: Tue Aug 05, 2025 6:40 pm 
Offline
SL6 Racer & Moderator
User avatar

Joined: Sat Oct 19, 2002 12:06 pm
Posts: 8948
Location: Silver Springs, Fl.
Car Model:
Most of my motors have stock rotating assys. I have one motor that had forged pistons. I got three 1/4 mile runs before it ate a couple of pistons. I still haven't taken the engine apart for a good look, Just removed the head. I'm thinking I either ran lean, or didn't have enough ring end gap.
A plate system is harder to get proper distribution.
I put several years of running a 7 1/4 rear, but mine was a 3.91 SG which is stronger than the open rear.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225


Top
   
PostPosted: Wed Aug 06, 2025 12:39 pm 
Offline
Board Sponsor & Moderator
User avatar

Joined: Mon Oct 21, 2002 11:08 am
Posts: 17064
Location: Blacksburg, VA
Car Model:
From all I have read and gleaned from experts (including Charlie), you are playing with fire with anything more than about 150 HP with a plate (with either cast or forged pistons). Best to do fogger for higher than that. You can also kiss that 7.25" open axle goodbye with a big N2O shot.

_________________
Home of Slant6-powered fun machines since 1988


Top
   
PostPosted: Wed Aug 06, 2025 12:52 pm 
Offline
EFI Slant 6

Joined: Thu Apr 18, 2019 7:57 am
Posts: 406
Location: Lawrenceville, GA
Car Model: 1966 Dodge Dart
Agreed, even with less nitrous off the line, that 7.25" isn't going to survive. You'll also want an engine to already have enough airflow to make a comparable power level to the nitrous horsepower, which is going to call for a much more aggressive build. It's also going to need a way more powerful ignition, at least something like an MSD 6 series.

_________________
Matt Cramer
1966 Dodge Dart turbo / EFI project


Top
   
PostPosted: Thu Aug 07, 2025 1:28 pm 
Offline
3 Deuce Weber

Joined: Mon Apr 04, 2005 5:28 pm
Posts: 52
Location: Vernon,WI
Car Model: 1966 Plymouth Valiant
no way I would mess with that much of an investment in the bottom end then go hap hazard on the fuel distribution. i played with a throttle body injection set up on my Aussie intake for just over a year. never felt the distribution was good enough to add the boost I wanted. ended up with a modified Offy intake with multiport. needed the extra room it provided for the turbo in my car. otherwise I would have used the Aussie I had.


Top
   
PostPosted: Fri Aug 08, 2025 3:32 am 
Offline
SL6 Racer & Moderator
User avatar

Joined: Sat Oct 19, 2002 12:06 pm
Posts: 8948
Location: Silver Springs, Fl.
Car Model:
Lawn dart. Just reread your first post. You stated Wisco pistons, and "stock" rods. Unless you are refering to stock 198 rods you will have an issue. The Wisco pistons for the slant six are designed for use with the longer 198 connecting rod. If used with the 225 con rod, you lose compression.
Also be aware that copper head gaskets are a pain. You need to do extra machining. "O" ring groove in the block and, Idealy, a reciever groove in the head. Also sealing the water/oil passages between the head and block can be a pain. I just run a stock "shim" gasket or a standard replacement gasket, depending on CR.
Why not larger valves? You should have a "fresh" valve job, so spend a little more for bigger valves.
Also don't overlook a higher stall converter, if using a automatic. Minimum of 3,000 rpm. Most engines don't like N2O below 3 grand, and N2O has the greatest effect right off the line.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 8 posts ] 

All times are UTC-07:00


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited