So ive decided that over the next few years im goin to build the moooost kick @$$ 4.9 ever. Or at least try. Soooo to do this, ive got some questions. Which block/head combination would allow for the most extensive work. I know that the EFI heads have shrouded compustion chambers so they are not all that desireable for a HIGH HP application. While I havent decided if I am going with nitrous or a turbo, 1 of the two will be utilized, and for that forged pistons are desirable, which v8 pistons will fit the 300, and does anyone have recomendations on which brand? For rods are there any H beam or I beam forged rods that will fit the 300?
Almost positive Im going with fuel injection, the question is should I buy a 4 bbl manfold and run TBI? What Im thinking about doing is taking a design from a 4 banger, and if youve ever seen a hi po intake manifold (look on eddlebrocks website) its got your runners, and one big, ill call it resivour for the time (just like what the EFI 4.9s have on top (that say Electronic fuel injection)), basically eliminating the upper half of the intake manifold as is. Probably throw the throttle body off a 351 on there, and fab up the mounting and throttle lines. For exhaust, im probably going to use stock EFI manifolds, or I might build something custom, but have them both dump together almost immediatly, and into a turbo. From their going to have the intake pipe go straight foward, and into a side mount intercooler (mounted in the front, reason for a side mound is they normally have the in and out on the same side, so I can go from their, straight into the intake. Water/acly injection will be utilized, and I will probably contact clifford performance to get a custom camshaft ground. The brains of the whole operation will be megasquirt and shock with extras (check ebay, supports things like traction control, shift lights, water injection control, nitrous injection control, launch control, barometric corrections (real time) over rec protection, over boost protection, knock sensor input, the ability to retard timing or drop boost if intake temp gets too high) A LOT OF STUFF. Its a long time coming, but again, its going to be funded over the next 2 years, and done right the first time.
whats it going in you ask? A stripped 280z will be the likely cannidate.
Motor expectations are 400 HP 500 FT lbs of torque ( and about 6000-6500 RPMS to boot), or bust! hehe.. In a car that will weigh about 1800 w/o motor (thats if the quote average for those cars of around 2400 is correct), we should have some fun. the license plate? INLINE6 heheh
or maybe ONLY6CY

basic questions again, for all out performance, should i go with a EFI or Carbed head, and should I run throttle body injection, or try to work out my custom semi stock injection system?

 

That will be a monster. Like that one beauty that Col Flashman created. 300+ horespower, what you might want to achieve in the 300 is the low end torque, and keeping a good flat torque curve. Id love to do that one day but i think the one i have no will spin a bearing within the next couple years. That tranny is really starting to make that motor wind right up. 490,000 km. Be nice got to wind her up to 6000 and twice the horepower and rubber ripping torque. Raw power. That would make some smoke on the asphault eh?

 

Try studying the Col's engine buildup first.

Good luck.

 

EFI is vastly superior to a carb. If you really want all out performance that is the way to go. The only drawbacks with EFI are the cost and finding someone who can tune it for you. Another option would be an carbed IR setup based on the EFI lower intake. Same drawbacks as EFI and not as nice. TBI is nothing more than an electroic carburetor. It still suffers from mixture distribution problems, especially if you have reduced vacuum at idle from a big cam, and flow can be a problem with the injectors hanging right in the path of incoming air.

Different piston and rod combinations have been discussed at length. Do a search and you will probably have more information than want.

The EFI manifolds are silly if you're going to spend all that money on performance. Do it right and have a set of headers built.

6000-6500 rpm is a lot of rev for a 300. Getting it to live isn't that big a deal, but just because it winds that tight won't mean it's making power up there. The biggest thing that seems to go wrong with 300 builds is that people build them like a 302 instead of like a 400 with two missing cylinders. The airflow needs for a 300 cylinder are about 30% greater than a 302, so the head and cam must be designed with that in mind.

 

Silver streak, are you seeing things? He never mentioned running a carb.

Carb HEAD, for all out performance.

Headers, no efi exh manifolds.

I would imagine your gonna need more than a stock 351w throttle body can support, since your using the megasquirt, you can pick and choose throttle bodies, would imagine a big single bore would be a good idea.

I'd say a carb intake, adapted to a throttle body/injectors, would be the best bet here, v8 people have been doing this for years, jeep did something simillar on their OE 4.0 engines as well. I keep seeing a clifford dual carb intake, with two single bore throttle bodies. As ss mentioned, a stock efi lower, with a plenum (or aluminum box) on top, might work well, then you could sit a couple throttle bodies on top.
TBI is not desirable.

Once you get the intake flow/head flow/cross sectional area/etc., surely any reputable cam company could set you up, I would be afraid clifford would charge out the wazoo.

390/351w pistons will work, depending on whether your thinking n/a-nitrous oxide or boost.

Ross would be a good place to look for rods/pistons.

Why not go all out and get a custom LS1 head made, I would imagine you know the one I am talking about.

Good luck!!

 

I guess so. I could have sworn that he asked if he should run a carb or EFI. Maybe I read the line about the 4 barrel intake and got lost?

I think a 302/351 TB will be sufficient, but will be at it's limit.

I would steer clear of the 390 pistons for the kind of rpm and power you want. 0.050 over is stretching it a bit on most of these. If you do go that route make sure you have the block sonic checked first. On a build like this a custom forging is the only way to go.

The LS1 head flows like Niagra Falls, but is a lot of work. You can get over 300 cfm for a 300 head, or if that isn't enough you could siamese two small block Ford heads for a lot less money and have the same results as the LS1 head.

 

From what I have seen, the ls1 wouldn't be much more work than any other cobbled together head.

Small block ford heads cheaper? LS1 aren't that expensive. You'd be looking at some port work to get a OE or cost effective SBF head to flow like the LS1, unless you wanna go with the australian aftermarket castings everyone is becoming familiar with. Maybe I haven't had as much luck finding reasonably priced SBF aftermarket heads.

300cfm ~from a stock 300 I-6 head = big bucks I would imagine.

 

Yes, porting the 300 head is big bucks for that kind of flow, and it will still have heat transfer issues between the intake and exhaust ports. A lot of that can be negated with the use of coatings.

You can buy a new set of TFS heads for a 302 and have them ported for about $1500. If you shop around you can find used heads ported for half that or less. There are out of the box SBF heads that outflow the LS1. Even a ported LS1 often won't flow 300 cfm. The head bolt pattern is different on the LS1 as well, even though it is close enough that it can be made to work. It would probably need custom head bolts to make it happen. The ports, especially the intakes, are also a very different shape than the stockers which makes the intake manifold that much more difficult to adapt. I think in the end you'd be money ahead with the Ford heads.

 

I get what your saying but if I recall correctly, $1500 would get you the custom LS1 head. $1500 TFS and then you shell out the bucks to have them cut up and welded. Heck why stop there, go with AFR.


Either will probably end up cracking so...maybe that ported stocker with some nitrous is looking better by the minute...

 

i dont know these things lolz. If 1500 to 2000 K will get the ls1 head, then I might jus go for it, the flow numbers were supposed to support close to 500 CFM, or at least thats what i was reading. Oh well, if thats the case, then intake will be need to be fabbed with runners ect, and exhaust will be fairly custom id imagine, but with that, and the clifford cam (the one that has power to 6500 will prolly be used.) and compression ratio near 9.5 or 10, a healthy 50 to 100 shot of nitrous should push it over the 350 HP mark with ease, and maybe closer to 400. The slight loss in TQ, or at least upward shift in RPMs might be what i need to both gain traction, and save the stock crank, which clifford told me would warp at over 500 HP or 500 FT Lbs. Oh, and if it doesnt work, ill just import the 260 PS 550 NM 4.0 monster from australia, i bet it gets good gas mileage, and it comes with a t56 so i can run at least 4.10s in the rear .
Time to go into the part of arkansas with no internet (darn christmas). Everyone have a safe and merry christmas, and keep the ideas coming.

 

Actually, if I were considering this myself, I might think against a crossflow head, either way your gonna need custom headers and intake (ls1 or SBF), not to mention, there is a high likelihood the custom head will crack where the two(three) pieces were joined, seems to be the nature of the beast.

Getting to 300hp isn't a problem, 400hp naturally aspirated is doable with ported stock heads, If it were me, I'd shoot for 350hp naturally aspirated with strong internals, add 100-125 shot...see what I could break. Then you have common parts and won't pay out the wazoo for custom intake/header work.

If this is a strip only deal and I were doing it, I would probably go carb. Sure efi is great but a well tuned carb isn't that bad.

Well enough of me trying to spend your money, have a good christmas yourself.

 

Only 9.5-10:1 compression? Why not go for 12:1, if its gonna be a strip car. I'd get a 240 head and get it worked to the moon. Port polish mill bigger valves rockers...

I agree with motorhead going with carbed. I wouldnt wanna screw with all the computer crap. 2 4 barrels can breath more than any TB from a 351 or 460.

 

300 H.P. @ 4600 rpm & 400 Torque @ 3200 rpm w/ a 9.5 to 1 C.R.
It idels @ 675 & is smooth as glass, a quarter was placed on top of the Valve Cover & it Did Not move Nor rattle @ least on the stand anyway.

Ross Pistons 4.060
Hastings Power Flex Rings .060
Federal Mogul Mains .020 Under
Clevite Performance Bearings Std.
Federal Mogul Cam Bearings Std.
Melling Torque Cam
Melling H.V. Oli Pump
Eagle H-beam Rods 6.300 2.100 Rod Journal
Crane Gold Race Roller rockers
ARP Main Stud Kit, Rocker Studs,
Fisher International Ballancer
Bore 4.060
Power Hone 4.060
Full P&P Intake & Exhaust
Performance valve job
Performance Balance job on Steele Crank w/ in 7 grams
Grind Rod Journals to 2.100
Plumb Intake for Heat via Water Pump
Deck Block to Square
Align hone to Factory specs
Deck block for Zero Deck
Offenhauser C Intake
Holley 1850 600 CFM
S.S. Borla 2 into 2 Header
8' of 3" tubes attached to Flowmaster 40's
4 Core Desert Radiator mated w/ the Original Radiator Housing
2 1,200 CPU Electric Fans, on @ 180*, off @ 170* mounted diaginally
MSD 6A Eclectronics Package & Coil
D.S. II Electronic Ignition

Happy Christmas and A Merry New Year

 

Reason for the Efi was I wasnt sure if I was going to go with turbo or not, and the thought of building a carb to handle a turbo is alot scarier than EFI. I didnt realize i could get over 350 HP out of a 300. As for crossflow heads, are you all talking about a custom crossflow because I didnt realize that there were any crossflows for the 300 or the 240 sister engine. If there are, link me please. Another reason for a turbo was if I stayed out of boost, especially in the target car, gas mileage would still be quite resonable, and the motor would be quite streetable. I wouldnt need that gut wretching torque to get off the line beause the car will weigh less than 2300 pounds or so, and again, out of boost and seeing 20-25 MPG should be that bad, with the right tune. Ok, well I found out time hadnt forgot ARKANSAS and I found the internet, so Im back lol. Are there any V8 pistons that fit that wont require a 50 or 60 over bore to stuff into the ford block? Thanks again, Merry Christmas all, and Happy and safe new year.

 

351w pistons would work, four inch bore on up.

some companies offer forged OE replacement type paw at performance a reasonable price.

we were discussion custom crossflow heads, there are inline specific crossflow heads for sale, check the other popular ford inline six website, under the big six section, will be titled "ford 300 crossflow heads".

sorry about the lack of specifics but the posts were blocked and wouldn't show up, wouldn't let me pm you either.