the new 400 motor

[snakeeater1968]

hey darth,

can we get some spec's and more information on the 400 sbc you showed on the home page ..... like stroke and what cam it had in it bore size and cam numbers pistions ect.

thanks

Snake eater

[Dart Vader]

It's the SHP short block, 400" 4.125 x 3.75". It has the upgraded H-beam and forged Mahle piston options. Pro 1 as cast top end kit with 215cc intake port. Holley 830 CFM 4150 HP carb, Comp magnum/steel rockers, OEM spider style hydro Comp Cams lifters.
It has a Comp Cams XTREME Energy Retro-Fit Hydraulic Roller Camshaft.

[snakeeater1968]

It's the SHP short block, 400" 4.125 x 3.75". It has the upgraded H-beam and forged Mahle piston options. Pro 1 as cast top end kit with 215cc intake port. Holley 830 CFM 4150 HP carb, Comp magnum/steel rockers, OEM spider style hydro Comp Cams lifters.
It has a Comp Cams XTREME Energy Retro-Fit Hydraulic Roller Camshaft.

thanks for the info darth,

one more thing can you give some numbers off the cam that was used on the motor and maybe some numbers if multipul cams were used and what intake...i'm thinking of copying the build

thanks alot

Snake eater

[powertvmark]

We did some cam testing with nitrous cams. The naturally aspirated cam below made the most power, on and off nitrous. Its a 12-443-8 from Comp. The motor didn't start to drop on power until 6500 RPM. It will have a 7000 RPM limiter and shift around 6600-6800. Even with a pretty heavy cam, the springs Dart put on the heads worked perfectly, no floating at high RPM on any of the 20+ runs we did.

This cam is decently aggressive for a street car. It is a light car with a 5 speed so we could get away with it.

The intake was the Dart single plane that comes with the Dart 215cc top end kit.

We will have the video build of this engine done in the next couple weeks. If you have any other questions, post them up.

[powertvmark]

Heres the link to the blog on the car:

take the spaces out below, I dont have 10 posts to do links yet.

htt p://w ww.street legaltv.com/forum/400-ci-240sx. html

[snakeeater1968]

We did some cam testing with nitrous cams. The naturally aspirated cam below made the most power, on and off nitrous. Its a 12-443-8 from Comp. The motor didn't start to drop on power until 6500 RPM. It will have a 7000 RPM limiter and shift around 6600-6800. Even with a pretty heavy cam, the springs Dart put on the heads worked perfectly, no floating at high RPM on any of the 20+ runs we did.

This cam is decently aggressive for a street car. It is a light car with a 5 speed so we could get away with it.

The intake was the Dart single plane that comes with the Dart 215cc top end kit.

We will have the video build of this engine done in the next couple weeks. If you have any other questions, post them up.

thanks for all the great info....did you guys try the vic jr intake or the team g intake by any chance, to get a comparison of how these heads build power in comparison to the flow and power w/ different intakes??? i know you were building a motor based on the top end kit but, i'm looking to get an intake based on performance and power ranges....like where does it realy make power the most power for a street strip application....i'm trying to see what the real numbers diffence is with a vic jr, team-g or the dart open plenum intakes... i want an engine w identical numbers as this engine has....what kind of extras did you do to the top end...and were thier any other carbs you tried w this combo??? what was it jetted at???? what was the AFR while it was on the dyno???? i already have the pro 1 215 w/ the super mod porting on them i found they make great power and am looking to fine tune the combo...i would like to build something very similar to yours....i drive my nova on the street and i also have a manual transmition....

thanks for all the info

Snake eater

[powertvmark]

No, only the dart single plane was used. The power band couldn't have been more linear. There was nothing else done to the top end except for the out of the box parts. The Holley used was the only carb we had on the motor and didn't see a single adjustment out of the box. It ran 11.8:1 on the low end and peaked at about 12.4:1 on the high end NA. Westech says that it is where about a carb motor wants to be. When I get it in the car and on the dyno, I may lean it out a little. Timing was at 36 degrees. On nitrous it ran a flat 11.5:1 pretty much. If I had the heads ported, it probably would have made closer to 550HP NA. Im happy with my engine and it sounds TUFF.

[snakeeater1968]

No, only the dart single plane was used. The power band couldn't have been more linear. There was nothing else done to the top end except for the out of the box parts. The Holley used was the only carb we had on the motor and didn't see a single adjustment out of the box. It ran 11.8:1 on the low end and peaked at about 12.4:1 on the high end NA. Westech says that it is where about a carb motor wants to be. When I get it in the car and on the dyno, I may lean it out a little. Timing was at 36 degrees. On nitrous it ran a flat 11.5:1 pretty much. If I had the heads ported, it probably would have made closer to 550HP NA. Im happy with my engine and it sounds TUFF.

sounds great....what did the compression ratio come out to be???and what size chambers did it have???how much was it total cost to build??? what is the spring size in the heads now??? are you running an msd and box???

thanks for all the info

Snake eater