I’m looking into building a new motor for my American dragster I’m trying to go low 4.50s high 4.40s and go 8.90 at 180-185 in the summer on race gas the car with me in with a regular XS 16volt battery weighs 1900 I will be putting a lithium in it this summer. I was thinking a 632 with an iron block just don’t know if I can achieve that ET with Sr20’s or if I need to go to a 12 degree kind of set up not wanting to spend an extra 7k on aluminum block any input helps

IF it will really weigh 1900 lbs. with an iron block and you in the seat...648 with NOT OTB 20 degree heads, a SV632 manifold and a 2.350 - 2.400 blade dominator..

FYI, you'll also need 2 lithium batteries

With me and a 582 iron block right now at a divisional event weighed 1904 I figured with lithium set up and maybe shedding a few pound I could get to 1860 race weight. So from how I’m reading you comment I could be reading it wrong and apologize if I am but your saying if I went to a 648 with sr20 heads with a single carb should be able to get me to that ET?

Yes, an iron blocked 648 with over 15:1 and with 20 degree heads from PAR or APD and a single dominator carb with at least a 2.350 blade will run those ET's at that weight.

I'd give the boys at PAR a call an consider an all aluminum piece with their Elite 20 program.

quote:

Originally posted by Hill racing:
I’m looking into building a new motor for my American dragster I’m trying to go low 4.50s high 4.40s and go 8.90 at 180-185 in the summer on race gas the car with me in with a regular XS 16volt battery weighs 1900 I will be putting a lithium in it this summer. I was thinking a 632 with an iron block just don’t know if I can achieve that ET with Sr20’s or if I need to go to a 12 degree kind of set up not wanting to spend an extra 7k on aluminum block any input helps

At 1900 lbs you will need 1050HP to run 4.50 in the 1/8 or 7.09 in the 1/4. That HP is based on racing at sea level so you will need to adjust the required HP based on the HP correction factor that you normally race in. So you are looking at 1100HP or more to do what you want. A 632 with Brodix Head Hunter heads should get you 1100 HP. Moving up to the BRX or SR20's would certainly give you more HP also, depending on the build with those heads you would be looking at 1140 to 1200 HP.

I friend of mine has a steel block (Dart Big M) 632 with Dart Pro 20 heads and he has run in the high 6's at 1925lbs. He wasn't happy with one lithium battery so he put his heavy battery back in which added a good 35 lbs to the car. He normally runs 7.0's to low teens in the quarter or high 4.40's to mid 4.50's with this combo.

This message has been edited. Last edited by: TOP38,

I agree with the biggest question here being weight.

A PAR 632 SR20 will do what you are asking at that weight

If you go aluminum block then a 615 will run the ET in summer heat you are looking at

Again, all depends on weight

Agree also with just calling PAR. His favorite is an all aluminum 615 SR20 and it’s what he builds the most of, but he won’t steer you wrong regardless and will build you what’s needed to achieve your goals

I definitely agree PAR has put some fast motors together with there sr20 program the only thing with going to them is in unfortunately I live halfway across the country from them and I’ve always been the guy to buy the parts for something step by step cause I can’t throw around 35k around if par would sell a top end kit I would definitely consider that just would be hard for me to commit to something across country

quote:

Originally posted by Hill racing:
I definitely agree PAR has put some fast motors together with there sr20 program the only thing with going to them is in unfortunately I live halfway across the country from them and I’ve always been the guy to buy the parts for something step by step cause I can’t throw around 35k around if par would sell a top end kit I would definitely consider that just would be hard for me to commit to something across country

I’ve seen PAR put together motors with top parts for cheaper than I could buy the parts for myself

Regardless, if your weight is correct then a well built 632 SR20 will get the job done

I don’t know the weight of the car, but I drove a newer American car a couple times last year with an aluminum block 615 with SR20s. Car has a wing, but lithium batteries and I weigh 160.

Made 1135 on the dyno and went 8.90 @ 179 at Topeka and 181 at Maple Grove.

With me race weight right now with a 582 iron block is 1904 last time I went across the scales

It will be heavier with a tall deck block. Again to run the quick and fast end of your ET and MPH goals anywhere but mile high and in any weather at your goal weight, you want the 648

no substitute for cubic inches ...

I've always heard "there's no replacement for displacement".

Keep your 582, add a TBS 250 Baby blower and 5 psi of boost and you will get the results your looking for easy

quote:

Originally posted by Wild Wild West 2:
I've always heard "there's no replacement for displacement".

Cubic dollars. Take care. Tom Worthington

quote:

Originally posted by Big Steve:
Keep your 582, add a TBS 250 Baby blower and 5 psi of boost and you will get the results your looking for easy

This ^^^^^

Disagree, several of those that jumped onto the baby blower bandwagon have found they aren’t good for bracket racing/driving the strip and have/are selling them.

baby blower is a viable option. One may need to alter their driving style for the finish line. Consistency isn't an issue, once one makes a few tuning changes.

Valvetrain is critical.

My suggestion of the baby blower was only a suggestion to meet the OPs ET and MPH goals for a whole lot less money than building an entire new engine. Whether you can win with it is up to the driver