alright so heres the deal im trying to build a 302 close to 400 hp. so far ive got hyperteutic pistons bored .030 over, comp cams xe274h, heads are still up for grabs but hopefully afr 185, holley 750dp (do they make a double pumper with vacuum secondaries? if yes does anyone have a part #?) on an edelbrock victor jr intake. i need to figure out everything else...alternator, fuel pump, water pump, ignition, radiator all that fun stuff right now i have an aftermarket flex fan that i got for free.
im kinda new to this stuff whats the difference and what performs better? also what do you guys think of the edelbrock performer rpm heads? is the extra 400-600 worth it for the afr heads? i figure without rockers the afrs are 400 more and crane 1.6 are around 200 right?
Both a vac secondary and double pumper both are tuneable to work about any way you want, but 99% of guys use the double pumper due to the fact that they have rear accelerator pumps to squirt fuel from all 4 corners instead of just the front like the vacume secondaries... and are all mechanical... no diaphrams to get holes in and such.. For a driver Id suggest either one... for racing application id suggest the DP For simplicity id go w/ a Edelbrock
Double pumpers (Holly 4150) use a mecanical linkage to open the secondarys, but if you have a mild engine or a heavy car, this can make the engine bog down when you mash the go pedal. To put it simply, this happens because the carb opens all at once letting a bunch of air in, but the fuel has to "catch up" because it weighs alot more than the air. Its a bit more complicated, but thats not really important here. To help with this, they have 2 accelerator pumps, one for the primarys, and one for the secondarys, hence the name "double pumper." The Holly 4160s have vacuum secondarys, which open the secondarys in response to engine load, so the carb won't open up more than the engine is ready for at the time. These carbs are great for daily driven steet cars with automatics, and heavy vehicles. You don't get that cool secondary sound the second you put your foot into it, but they are alot more forgiving to drive with. That said, if you go with a real bumpy cam, you can have a bit of trouble tuning a 4160 right, because the vacuum signal won't be very good. As far as performance, a 4150 might *just* edge out a 4160, but you have to have it tuned just perfect, like I said, the aren't very forgiving.
Thats always a arguement here... I say it'll work just gotta tune it right... A lot of people say 650 is more suitable
well i think i would rather have more carb that i can tune down than not enough carb.. so hows about those accessory parts.
Standard waterpump would be fine... same with alternator, etc As for fuel pump... i vote for a 110gph Holley mechanical or equivelant... just because they are affordable and can be used for alot of applications. Id suggest an aluminum waterpump, just ask for one at the parts store. I forget what all they came on... but I think 90 ish mustangs. Radiator... you'll be ok with a regular copper brass radiator for a V8 maverick Id think. I never run flex or direct fans tho, always electric. Put in a 180 or so thermostat and you should be fine. If your going to just drive the vehicle id also just recommend a duraspark igntion, or even a petronics set if you dont have electronic ignition.
im switching over to an electronic i just havent decided which setup yet the car is mostly for the strip but itll get driven on the street on special occasions n nice days. i also work at an auto shop so all stock style parts i get at wholesale cost if that makes a difference in your recommendations.
Get the aluminum waterpump. Seems to last a bit longer in my experience. They arent any higher either. I dont know of any stock replacement mechanical pumps that put out any more Gallon per hour than others... maybe someone else can help you on that. Did you mean you were swapping to an electronic ignition/fuel pump/fan? Im not sure what you meant by your last post
i was talking about ignition and if i switch to an electric fuel pump is still in the air because as i said im kinda new to this so i dont know the advantages or disadvantages this is my first engine build and my first drag car. im not sticking to strictly stock style parts i was just pointing out that stock parts that perform well are cheap for me. i also might switch to an electric fan later on ive heard you get some decent power gains by eliminating a major pulley.
so i think all i need to know now is what you guys recommend for electronic ignition and your opinions of edelbrock performer rpm vs afr 185 heads. and if anyone has a different suggestion for something im open to it.
Ive heard best results from the Edelbrock heads honestly. I still suggest the Duraspark ignition.. Im running it and alot of guys are also. Its the baseline for MSD and such. MSD 6a is a good ignition also if you want to spend the money Id just get a duraspark box, duraspark dizzy, a big cap and rotor and some good plug wires and call it a day
yeah i think ill go with the duraspark whats it out of so i can order it or parts numbers? i figure its a reasonably priced upgrade and if i switch later i didnt spend much on it. does anyone else have any opinions on the edelbrock vs afrs i found a set of edelbrock performer rpm heads with crane 1.6 roller rockers for 950 and a set of afr 185 without rockers for 1400..
