[Johnny406]

My 78 Trams Am bracket car runs heads up 1/8th mile drag racing on hard tire (real street tire) from time to time. It really is a bracket car with a .030 over 455 with Icon forged piston on 6.625 Scat H beam rods on a stock crank with a bottom filled 2 bolt block with factory bolts (ARP was out of stock of the 2 bolt studs back in 2010). Heads are out of the box 87cc D-port heads with a off the shelf Lunati 60905 HFT and Rhoads V-max lifters.

I sprayed it a lot at 100hp last year, am I pushing my luck with a 150-175 shot this year?

[Mike Davis]

In the early 90's I had a 2 bolt 400 with a N crank, I had a 250HP NOS cheater plates on a Doug Nash Tunnel Ram. Block was not filled and no lifter bore brace. Ran MANY bottles through it and it had over 600 N/A passes and 250 NOS passes when I pulled it apart. Still looked good. Only replace head gaskets every 200 passes as a precaution.
In the late 90's I sprayed 200 shot on a factory 428N Crank but it was in factory 4 bolt block. Never had an issue.

Should not be an issue as long as you pull timing and have the fuel correct and can read the plugs.

A good tune up on a decent block no issues,
A bad tune up on a decent block- issues.

[greggutknecht]

I sprayed around 450 on mine with a fogger the crank never had an issue it was the crack in #2 main that ended it.

[Half-Inch Stud]

Originally Posted by greggutknecht

I sprayed around 450 on mine with a fogger the crank never had an issue it was the crack in #2 main that ended it.

Holy crap 450 shots into a decades-old cast N crank ought to be some kind of record.

[BADDTA]

What head gaskets are you running? We only sprayed 150 last year and we had leakage on center cylinders with Butler gaskets after 10 passes. But they were fun and wild for 10 passes...

Brian

[BADDTA]

Originally Posted by Half-Inch Stud

Holy crap 450 shots into a decades-old cast N crank ought to be some kind of record.

Yeah, you have to look at the source... Gutnecht sprays 200 into his minivan just to start it for work! Lol

Brian

[greggutknecht]

The car ran 9.11@150 wasnt bad for a pump gas motor in the late 90s.

[steve25]

In large part it's also rpm that tares motors up, not just hp!

The G force loads go up with the square of the rpm!

A 150 to 200 shot should be fine if your system can supply the needed fuel volume and you keep the rpm about the same.

I have used Fel Pro 1016 head gaskets with 10psi of boost making 650 hp without issue with iron heads for years , with Aluminum heads changing them out once a race season is a safe way to go!

The concentrated heat of the center Exh ports with Aluminum heads just makes for too high a expansion and contraction rate which over time rips head gaskets up unless your block and head deck are cut like a mirror smooth!

[mgarblik]

Originally Posted by Half-Inch Stud

Holy crap 450 shots into a decades-old cast N crank ought to be some kind of record.

We ran a similar nitrous load on an N crankshaft for years in the Grocery Getter. Never cracked a crankshaft and never had any issues with them. They are very underrated and plenty strong with proper prep. That prep for us included grinding an 1/8" radius in all journals, careful de-burr, detailed oil feed holes. Also ran aluminum connecting rods and 4-bolt straight caps in all 5 locations. This set-up eventually over many years yielded 3 broken 455 blocks. All three broken from the #2 main oil feed hole in the block to the cam tunnel. It's anecdotal, but in my mind, that was a weak area in the block. Each block looked the same. The crankshafts were fine. These were 3.25" main N cranks turning 7500-7800 RPM.

[Half-Inch Stud]

Fantastic. Knew the cast PMD N cranks were up to racng, but didn't know they were capable of high nitrous levels.

The #2 Main Crack up to the Cam bearing has been gone over a bunch

[greggutknecht]

On my crank we turned the rod journals to 2.100 and ran BME rods.

[greggutknecht]

Ran the 1016s on mine but only held up for about 6-8 passes with that much jet.

[Johnny406]

I have 1016's on them, heads are Edelbrock alum D-ports. I only spray for 1/8th mile heads up and I don't hit the button until 2nd gear. I have a Wilson Manifold 2 stage plate on the way, thought of adding 50hp off the line as I'm running a true street tire (Future 295-50-15's) for the hard tire class (no prep) and then 100-125 on the button if needed. This weekend for the first race I was just going to bump up the single stage from 100 to 140ish and change the plugs from Champion RC12YC to a RC10YC (they don't make a RC11YC)

[steve25]

Iron heads?
Head bolts or studs?
The only time I blew one out was when the motor went lean under throttle from a failed electric fuel pump.

[Johnny406]

Originally Posted by steve25

Iron heads?
Head bolts or studs?
The only time I blew one out was when the motor went lean under throttle from a failed electric fuel pump.

Edelbrock alum with ARP head bolts.

[Mark G]

Originally Posted by greggutknecht

Ran the 1016s on mine but only held up for about 6-8 passes with that much jet.

You are the man Greg also a good friend...lol

[Scott Roberts]

I ran a 406 with 16'S in the mid 90's on a 250 hit.. 2 bolt block and nodular crank.. no issues at all..still have the motor complete on a stand.

[taff2]

Retorque,retorque,retorque - the only way to make the headgaskets live with high cylinder pressures.