motor combo help

[81elcamino]

hey guys, im building a 388 small block with forged pistons, 190 patriot freedom heads port matched to a perf rpm mani, 110 fuel pump, high flow water pump, high flow oil pump, Lunati #638-60104 with 1.6 rockers, and a coan th350. I dont have a carb or converter yet, the cam says it likes a 850 carb( i think thats a little too big) and a 2800 stall. Are those right? is anybody running this cam? oh also im building this motor for spray,i wannt to get about 430 on motor and put a 100 or 125 shot on it. what do you think? its going in a 81 elcamino with a nine inch with 3.70s and a 28-11.5-15 quick time pro.thanks, joe

 

[86Cutlass383SR]

You didn't state what you're final compression ratio is going to be (dished, flat top, or dome pistons?) or head cc's. Is this a street/strip driver or strip only car? Is it stock weight or lightened any? All this will help with both cam and converter decisions. Call the converter company will ALL your vechicle info and they can recommend a stall for you. Unless it's a strip only car then I'd say an 850 is a little big unless you're good at tuning/modifying carbs. Better to err on small side.

Make sure you run the ZDDP additive when you break in the flat tappet cam! Newer oils have been reducing this additive and it's VERY important to run it on a new FT cam or they will wear out sooner. Most cars today run roller cams and no longer need this additive.

 

[megaladon6]

when i looked it up it said 750cfm carb which would be fine. don't forget that you should use forged rods and crank with nitrous (i see you have the pistons) also don't forget to check your pushrod length since you're going to the 1.6 ratio.
x2 on calling a trans company about the converter stall

 

[81elcamino]

ohhh sorry their 64cc heads and the pistons have a slight dish, the comp ratio is 9.9-1. the car has been lightened some with a fiberglass frontend and aluminum components, i contacted coan trans about the converter, just waiting for a response, thanks alot guys

 

[81elcamino]

the car is also gunna be a street/strip car. i have already checked the pushrod length and i also know about the additive for flat tappet thanks again

 

[Phoenyx]

Someone correct mew if I'm wrong. But I have heard that high volume oil pumps can suck the pan dry unless you have a high cap oil pan.

 

[megaladon6]

it is definitely recommended if you're pushing the car hard, but i think (when drag racing) that you can just add an extra qt. if you're auto-Xing, it's a must have to have a deep sump and baffled pan. in normal driving it's not a problem.
if you have med-large bearing clearances and especially if you have an oil cooler you need a HV pump. you also need to make sure that the pickup has the proper clearance to the pan--about 3/8-1/2in

 

[81elcamino]

oh i didnt know that, will it suck it dry? i have a 7 qt pan so i thought it would be fine.

 

[NAILS]

your using the wrong cam for big horsepower acheived via juice. you need a solid roller made for nitrous. http://www.summitracing.com/parts/LUN-50157/

make sure that bottom end is forged and in a set of 4 bolt mains. a 750 carb should be plenty
and you have a pretty nice combo of gear ratio to tire height,

 

[81elcamino]

thanks NAILS but I already have the cam and engine together except carb pretty much. im only gunna be spraying sometimes and Lunati said that this cam likes up to a 200 shot which im not gunna go that big! lol i wish tho maybe down the road.lol. im gunna be switching to those tires next summer and hopefully it hooks! thanks