Noob Looking To Build NA Stock Car Engine

SIDEWAYS · Post by **SIDEWAYS** » Thu Oct 18, 2007 7:49 pm

Hey Guys, I think this site is great. Lots of info.

I may be building a dirt track car for a 1/2 mile high bank track. Very fast, about 100mph on the straights.

Rules are suppose to be stock, but you know how that is.

The car is an 81 Challenger set up for the dirt with a blown up D50 (G54B)?

Has the D50 4 speed trans. I assume wide block?

My questions to the board is what will be the most bang for the buck engine to build? Do I use the D50 block & swap in other mitsu parts, or just start from scratch?

The track runs 2 classes SOHC & DOHC cars in the same race.

SOHC would be the easiest as the car has the manifolds already . Holley carb setup. (If they will swap)

But I am open to building a DOHC if the electronics are easy (no charging system in the car now) & I can give the car some kind of Mopar or Mitsu name to justify it came with a DOHC from the factory.

I will be running against FWD Honda's & Nissan's, so I need power.

Thanks in advance.

SIDEWAYS · Post by **SIDEWAYS** » Fri Oct 19, 2007 6:26 pm

Thanks for the info.

I have also been reading some threads & see that a 1.8 head will give me about 13:1.

Are they harder to find & or more costly?

I assume this will all bolt up to my d50 trans. right?

Will the oil pan work & how about some kind of header?

Was there any rear drive car with a twin cam that I could use to name the car?
Track rules.

If not how is the sohc 2.4?

Thx

89coltgt · Post by **89coltgt** » Sat Oct 20, 2007 3:11 am

smog wrote:actually its the 1.6 head I believe the 1.8 head is the same as a 2.0

No, the 1.6 head and the 1.8 head have the same combustion chamber size-only difference is that the 1.8 head has the same size intake and exhaust ports as the 2.0 head. So...the 1.8 would give you the higher c/r and bigger ports

SIDEWAYS · Post by **SIDEWAYS** » Sat Oct 20, 2007 9:33 am

OK

So a 2.4 block, wide, 6 bolt.

1.8 head, which year is the best?

Which cam gear set up do I want to use, & timing?

Cam recommendation for oval track? 4500-7500

Which manifolds do I use the 1.8 or 2.4?

Thanks again

89coltgt · Post by **89coltgt** » Sat Oct 20, 2007 10:19 pm

smog wrote:you sure about that, I was told earlier the 1.8 head had different ports. Anyhow, you want smaller ports for a na.

Yessir, the 4g61t guys use the 1.8 heads that way they can maintain the same c/r yet flow like the 2.0 head due to the larger ports.