I know the nascar guys run an 830 holley. Would a 4500 dominator make more power?
thanks.

Yes

Hi Alan,
thanks for the reply.
would either 1050 and 1150 carbs work?
thanks.

It would make a difference on how many CI and the RPM
you plan on turning

The maximum size allowed by NASCAR is the 830 CFM Holley. The actual carb used by the top NASCAR teams may look like a 830, may have the correct dimensions for a 830 Holley-----but the are not a 830 Holley.

Yes, a P7 can use more than an 830, but how much more depends on RPM the engine is running. When we used our 358" P7 in an 2300 lb. oval track car, we used a highly modified 800 Holley---and it was good to about 9000. The cylinder heads are highly efficient, so it doesn't require as much carb as less efficient heads do.

Hi,
were you rule limited to 800 cfm for that oval track car?
thanks.

No, there are NO engine restrictions for late model dirt cars in the US. The ONLY restrictions are one carb and one spark plug per cylinder.

But, we raced primarily on short 1/4 and 1/3 mile tracks and sometimes we had RPMs down as low as 2500 under race conditions. So, engine response was important. And the 800CFM was seriously worked---flowed well over 900 CFM and the fuel curve was good for our type of race car.

Where can you get mechanical fuel injection for the R5 P7, what part number is it? What is the approximate cost?

There are only a few intakes available to for the R5P7 motors. One is the original casting of which I think there are 3 but could be as many as 5. These are for specific tracks and some teams got their power in different ways from others.

There is a company that makes a cast intake that will take either a single 4 or a doul 4. They are a little pricey at $1600 each.

Then there is the all out lets go fast model which is the Sheet metal version and best bet there is a 2x4.

Now for the injection, you will need a specific intake built so your choices are limited. Built means either modify a current intake or have one built.

I know the engine builder I talked to said I would make the most power with a sheet metal intake. Not sure if I want to drop the $4000 on one or just pony up the $1600.

Yes 40Ford is prob. the most knowledgable on the board about these followed by Jesse(R5P7Duster) I am still a guppy in this shark tank...

Charles Sanborn (40ford) had Engler Machine make his stack injection, I think it was a one off. Contact them and find out

Engler had three castings for "I think" a Toyota or SP-2 sprint car head that had not had the manifold bolt holes drilled yet. The port spacing was almost identical to the P-7, so it was just a matter of drilling the P-7 bolt pattern and matching each base to the heads. The butterfly bodies are separate and could be bolted to different bases if needed. They (Sanborns)had three different sets of P-7's (Elliots, Davis's and one other, Arringtons, maybe)so that gave them flexibility if they decided to use a different head than the Elliots, since from what I understand, the intake ports are somewhat different on the three heads.

Georg,
Spud is great, but I think in this case, Engler is probably the only one that has the casting base that will work with the P-7 head, and I meant to say SB2 above, not SP....fat or dyslexic fingers on the keyboard....
BTW, I only answered for Charles last night because I knew it was late and he was already in bed.....

Oh yeah, most definitely would be the simplest way, especially with the P-7 being a rather specialized head. In Sanborn's case, the nostalgia association we run required straight port injection only, along with zoomies instead of collector headers for open wheel dragsters/altereds, although they have since relaxed the rules in regard to tunnel-ram/hat combo's. If Sanborn was starting from scratch building the car for the present rules today, he may very well have gone the manifold/hat route. And I apolgize for somewhat getting this thread off the OP's topic....

Soory I didnt knew about those rules in nostalgia class

I'm running a quickfuel 4150 1050 cfm. The engine handles it great and performs much better than with the 900 I had on it originally. Granted both carbs worked well. I have no expeience running both in warm weather though, I ran both of them in -10° to 25° F

Tim Engler was very instrumental in supplying the stack injection for the P7. It was not just a matter of "adapting" the toyota or SB2 to the Dodge. The basic mold was used but a custom program was written for the cylinder heads. We supplied him with heads, valley cover and specific dimensions as well as air flow (cfm) to develop what is currently on the engine. He treated our project with as much attention as a team that would order multiple injection units (we only needed one). His help and advice after the fact has been second to none and always willing to listen and advise when asked. FWIW this engine is for sale (complete down to the custom converter) as we have moved to the 7.0 pro class with a 607 injected hemi. The 358" P7 achieved a best of 7.40 and more can be gotten but the hemi engine sort of just fell in our lap as a joint venture and we couldn't pass it up (besides it just looks plain sexy in a full bodied FED). If anyone has questions or wishes to inquire feel free to PM me.