Thanks to Regisgt4 I have a couple sets of throttle bodies to adapt to the 308's I'll post some pic's and look forward to hearing what others think about the best way to execute this installation. Something that dawned on me yesterday is how different the 4v intake is vs. the 2v . . . the 4v has a seperate base doesn't it that will allow the throttle bodies to pretty much sit vertical . . the 2v I think I have to make adapters to change the angle the TB's sit on the head. Thoughts? cheers all .. fun project. Sean
I'm about to do a set for the QV heads I have I think and flow match them before I list them for sale. You're right that on the QV it's a pretty simple job I think. On a 2v, I think you'll still have room to do a simple adapter, the is no reason the TB can't sit at 45 degrees as long as they don't hit each other in the middle. I would make the port/manifold as straight as possible. Throw a piece of 1" stock in your prototrac and circle mill the bosses leaving the flage at least 3/8" thick.....then slap the TBs on and you should be good. That means re-spacing the TB set to match the 308 bore centers, but that is a pretty easy job and the set-up will flow much better then the twisty stock type carb intake.
yeah I'm gonna go hold them up at 45 deg and see if they intefere . . I think they will . . for simplicity I might just use the carb intakes I have for one of my 2v motors. on the 4v config do you have the throttle bodies orientated the same relative to each intake port? . . or do you have the stock linkages on the same side and not moving the linkages meaning the injector spray direction is different between the banks? .. don't you have enough to be working on BTW?? cheers
They'll fit. There is way more room on the QV, but still plenty on a 2v. On a slightly related note, I found a cute little injector to help solve the QV to EFI clearance problem too. The injectors want to be on the outside , they want to point as straight at the valve as possible.....and definitely the same on both sides if not you can almost bet on bank to bank mixture issues due to differences in the way the fuel atomizes in the ports. I do have too much on my plate but I need to sell the QV heads to pay for the v12 project and I think theyll be a lot easier to sell with the TBs matched so I can say bolt this stuff on an you will make 320-340hp. If I sell the heads alone Id be afraid whoever bough them would bugger the flow up with what even they use for an intake system and be disappointed in the final result. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I just went and played with it and here's what I've come up with: they won't fit at 45 deg on the 2v without modifying the water piping or going to a remote mount oil filter . . it could be done but here's what I think I'm gonna do on the 2v . . I can retain the factory cycle spacing and linkage and make an intake that's a flange with holes machined at compound angles that will position the ends of the tubes right in the proper locations to use the throttle bodies as they are . .. I'll interpolate the round area to accept the rubber boots after it's all welded up so everything will be on location . . . I think the only brain teaser will be the compound angle setup and layout . . I have a fixture to hold a flange/intake at any angle already. cheers
they'll be pretty much standing straight up vertically and in that configuration looks like the injectors/rails will be best on the middle of the valley area . . . gets the throttle linkage away from the oil filter too . . I think I'll handle the throttle linkage by running 2 cables to a junction where the one cable from the pedal will attach to it . .. . like my golf cart brakes cheers
I think remote mounting the filter will allow for direct mounting at 45 degrees and for the other bank the throttle cable could run under the stock water piping . . the only thing I like about making another intake like what I'm thinking is I won't have to change anything on the throttle body assemblies . .. . gotta chew on this one a bit.
The question really comes down to whether you want to build a simple bolt on set-up that makes good hp or you want a set-up the makes the most hp. If you aren't planning to do any flow work you are air limited to about 260-280hp anyway so the bolt on set-up is probably the best path for stock heads. If you have thoughts of ever getting the ports fixed it's probably worth the effort to set the TBs up to be as straight a shot as possible and then something about 320hp seems like a reasonable expectation.
two cables will certainly work, but you'll probably find it's easier, cleaner, and more reliably to run the stock cable to a shaft with a couple arms on each end to drive the TB banks.
looking at the angle the 2v port enters the head the TB's standing straight up I don't think is much of a compromise . .. I just laid it all out in 2D and I like how it looks . . . in a way the lower part of the manifold that I'm going to make is just like the stock 4v lower portion . .you're standing the TB's straight up on that yes? yeah I like that on the throttle linkage . . that'll really be it's own packaging excersie to itself. cheers
I was just looking at the cross sections in the WSM and you can see how steep the port enters in the 2V and the 4V . .. for some reason I thought the 4v had a seperate base down there . . the angle is almost horizontal on the manifold surface .. I can probably tilt them a bit on the 2V.
No. I will mount them in line with the port which is about 11 degrees off vertical. On the V12 though there just isn't roon to keep them straight, I'll about a 20 degree kick I think....one more thing on the list.....
here's a layout .. . I can rotate them a bit if I have clearance in the middle to line up with the ports better . . that's what the bottom left layout shows . . . that's 5 degree increments cheers Image Unavailable, Please Login
looks good. Now remember, there is absolutely nothing majic about vertical with EFI, no float blows mean no orientation limits. Also, be sure to layout room for a nice big radius in the bends, I wouldn't use anything less than 2" centerline radius and 4" would be better.
okay thanks for the tips on radii . .. optimum distance throttle blade to valve is? the hidden lines are just for me to get rough sizes . . I'll drill everything small and open it all up by hand . . .I'm thinking about doing the flanges first . . that's gonna be most of the headache .. I'll have to setup each angle so I want to put a tooling ball on my fixture to pick up a home position 'cause I'm gonna tilt the fixture so I can interpolate the holes to whatever size I end up making the runners . .. the only reason I'm trying to stay vertical is to maximize working room in the middle . . think it was pretty tight . . gonna go take another look and post some pics. cheers
There are lots and lots of theories on that. The 355 has is centered between the bacl of the valve and the top of the velocity stack but I really don't think it's critical.
confirming a few dim's and clearances . .. I think I might cut something for it tomorrow. Image Unavailable, Please Login Image Unavailable, Please Login
What sort of total cost would this set up come out at. I am currently considering one of the superchargers that are available, but after seeing this I am wondering whether to go down that road instead. I have an Xdi but presumably would need to change that for an Xdi2. Also I have an old pair of 4v intakes that I bought on fleabay a few years ago if they are of any use for modification.
I'm not selling anything . . .you can copy what I do . . .there's a chatter on here that's gonna market it so be patient.
bummer . .. got some inteference issues with one of the manifold studs at the compound angle . . I've got a few options . . . could just seperate the throttle bodies as pairs . . I think that will solve this clearance issue . .. mentally masturbating over whether to do that or just split all of them and get rid of the compound angles on the intake . . splitting all of 'em spreads 'em out and gets the linkage near other "stuff" . . . . cheers Image Unavailable, Please Login
after a semi sleepless night I'm thinking machine the outer runners straight and then the inner two at a compound angle . . might be easier to make all new connections for the TB's and spread 'em out but I'm trying to use all the stock linkage and it starts getting close to a lot of things if I add the length.
after a couple more hours of staring/cutting/fitting . . . I'm liking what Newman mentioned in Mark's V12 thread . . making the runners longer and crossing them over to the other side . . was just hoping whatever linkage I came up with on the 2v would work on the 4v which is a bit simpler I think. here's a pic of something Modena use to make or probably still does if you've got the bank whioh along those lines. I'll figure out the pic later .. it's a bitmap image. cheers
alright doing this makes me want to take the easy route and buy some 2 1/4" i.d. silicone elbows (edit: 45 degree) . . . might be a good first itteration and can always make a billet runners later when everything's layed out. thoughts anyone? . . Summit has some 45 deg elbows that look alright . . Image Unavailable, Please Login
Mcmaster has aluminum pipe elbows that find there way into just about every manifold I build it seems like. If you use the silicone 45s you'll probably want to do something to secure things a big more...it seems like the TBs would be pretty floppy if you just attach to the 45s.
