Be been on the fence for a while about permanently installing a cage or roll structure and finally got up the nerve to start in on it. I was struggling to find a kit from anyone for s good price and felt that I could buy the steel and do the bending to get the job done myself. In my struggles I decided to buy a main hoop but struggled in finding one to fit from an online supplier. As it turns out competition products main hoop for a 1970 to 1981 Camaro was a perfect fit and at $62 shipped to my door it was a no brainier. It definitely gives me the flexibility to build the rest how I want and with mostly straight pieces. If anyone is interested the part number from them is C3121. I'll post pictures soon. -Ryan
Ryan, is the car going to need a rollbar or are you just putting it in for safety sake ? I have been avoiding putting one in my car but need one to run at full potential. Are you going to race at PIR or Woodburn,perhaps we will see you there someday
With just a 6 point & sub frame connectors & decent traction bars you will get better launches.This will make your 60fts improve because no more body flex.Probably with some chassis tuning & 9in slicks I bet you can gain at least 1 sec. in qtr. mi. time because you will be able to put all the power to the ground,good luck & have fun,it`s going to take me at least 2 more yrs to get to the trk.
Hey Mike, For drags, the car will be close to needing one with the current powerplant. But I intend to do some road coarse as well which mandates a cage with door bars unfortunately. I race a lot at both Woodburn and PIR so probably either way. Plans for the future of a turbo 351 with megasquirt managed sequential port fuel setup. Current engine is a 302 with batched port fuel, mega squirt controller, Flotek heads with minor port and bowl work 2.02, 1.60, 195cc. Howard's mechanical flat tappet 106 LSA 240/246 at .050, .573/.590 on a 1.7 rocker. Pistons are .012 out of the bores. 2 VR, with .031 quench and 55cc chambers. 30 over, Heddman 1-5/8 long tubes, OE 5.0 FI lower intake with my own upper to convert to single plane. 24 lb injectors, flamethrower coil controlled by MS2. Last time the car was weighed, it was tipping the scales at 2400lb. But I think I will have shaved some and gained more back with the cage. As long as I'm under 2800 lbs as far as I understand, SCCA only requires a 1 1/2 dia roll structure. NHRA requires I think 1 5/8. The Camaro hoop works out fine at 1-3/4. I'll be aiming to meet tech requirements for both bodies for when I can afford to go faster.
Nice motor setup. What throttle body is that? The main hoop looks a little tall for anyone wanting to keep a headliner. Do you plan to cut it down a little so it is not soo tall? Aesthetically, it may actually fit the contour of the B pillar better if you lowered it down about 2".
Yeah, it's tall alright. I'm pogoing to cut it down for sure but I didn't have a chance to before u snapped the pic. The T-body is from a early FI truck 5.0 and has, if I remember properly, twin 56mm bores. They are cheap and fairly available.
Love these kinds of builds. Ryan, not trying to add more unneeded stress to your build or start another big debate for the debate team around here(although there aren't many hardcore engine builder types here anyways). Just friendly advice about running much tighter than normal quench heights on anything spinning higher rpm. After having done enough builds for myself and others while simultaneously studying this stuff almost every single year of my life I would surely say your "too tight" on this combo. Budget short-blocks/cast components can still get the job done well enough for most.. but you MUST add margin based on the physical stresses the parts are being used in and assure that they fall within the specific parts design limitations. And with that cam you'll likely be power peaking somewhere at least around 6,700'ish once it's sorted, plus the added over-rev capability past peak.. should zing to 7,000 rpm easy as pie.. to reduce ET/laptimes, so things will start to rock and roll while stretching and noodling around a bit, not to mention the aluminum piston and the head grows too(assuming the much preferred aftermarket bolts are doing their job and the head isn't lifting, this can compress the gasket slightly during sustained peak loads/higher temps and further reduces the original calculated quench height). MLS head gaskets can help this issue too but more $$$. How far you go out onto this edge should be fully dependent on the parts and blueprinting precision used. Hopefully you have slightly longer/stronger aftermarket rods with bigger bolts and pistons with at least long'ish skirts to help avoid potential issue. Shorter pistons are worth power but they come at a price as they increase rock. Longer rods help counteract that tendency. Your bigger clearance issues eventually come after the engine wears past optimum and the bearing clearance along with skirt/bore starts to go out over time(ring seal can still be perfectly fine though), and history shows that piston rock contact patches will eventually pound the bearings out or crack pistons/rings and bite you in the keester. Most running without knock sensors never hear the cumulative damage occurring and many have driven right over their pans which is obviously one of the most dangerous things to do in a racing/speeding car. Have you run that manifold before? Seen tons of Chevy guys plus a few other Fords do similar and I'm very interested to see how the shorter runners affect the engines power band. Should push the torque peak up several hundred rpm and will surely make the car more tractable down low for cone racing. Absolutely love the tight lobed cam.. many get this wrong with shelf EFI or alphabet cams.. but you have tuning at your fingertips. Will you datalog too? Would also seriously consider chopping that cookie cutter collector and running a merge "cone style" collector. Haven't run you numbers through pipemax but the engine is still small and would guess ballpark optimum choke ID of around 2.25" - 2.375" then back up to around 3" for the collectors/mid-pipes although me thinks 2.75" OD piping would be more towards optimum for this combo). The higher compression is surely good as it inherently reduces reversion but adding the collector choke will greatly reduce that tighter cams reversion up into the plenum box and make it much easier to dial in the tune as well. Powerband will be fatter, crisper, wider, even more efficient/cleaner.. engine will feel more refined and larger than its actual size as peak torque goes up. Pretty big dollar/horsepower gains to be had from a simple weld on investment. Ideally, you build them custom to begin with utilizing a bit shorter primaries or in a perfect world.. a 4-2-1 setup for broader powerband. But good headers are not cheap and modding shelf parts can get you much closer than most will think. Do you know what "pipemax" is? Or did you use any other decent calculators to check the resonance for those shorter runners? PS. sorry for all the buried questions.. I got too excited about engines again. I better shut up and go work on my junk for a change. lol
Ryan, now I see why you are a Broke A$$ Mechanic. Funny I havent met up with you before but I havent raced very much lately but plan on getting back into it. Keep up the good work
I'll try and answer all your questions. Let me know if I miss any. That quench measurement was based on the tightest cylinder. I have considered running a 10 thou shim gasket to gain some more clearance. Pistons are forged trw pieces, Rods are or fit with arp waveloc 5/16 bolts and premed and tifftrided. Crank is also an OEM piece that's had similar treatment. I figure if Shelby and his team could run them at over 7 grand in harsh conditions then I hope I can too. Haven't used this type of throttle body before but I hope it goes well for me. There shorter runners were all measures out and calculated out by hand to the 4th pulse if I can remember. Plenum is sized at just under 2x displacement. Heard of pipe max. Never used it. Haven't looked too much into exhaust either. 3" collectors right now with 2.5 two chanbers
NHRA wants everything 1& 3/4 inches which includes main hoop,side bars to floor,roof box with bars off them to the front floors & the 2 bars coming off main hoop going into the trunk.Most of the other bars can be 1 5/8 in,all have to be .134 metal thickness to be certified.Most builders rule of thumb is to not have pistons more than .005 out of the blkeven though I have seen some exceed that.
Wow.. old school.. you put a lot of time and cash into improving those stock parts. I'm nose deep in bodywork right now.. but if you PM me all your engines physical spec's I will run it through pipe max and send you the minimum to maximum engine spec's printout. Here's the program layout to get an idea of what I'll need to plug into it. Just remember "garbage in garbage out" applies heavily and the more precise your numbers are the closer you'll end up to optimum data. If you have it all sorted and figured out well enough or don't care about "optimum spec's" simply because most of it can't be changed at this point?.. probably not even worth the electricity to punch in the numbers. Couple of quick and friendly tips to consider. Shelby's cars weren't the most powerful combo's when compared to today's parts so it's not apples to apples lined up across the same exact board.. if you catch my drift here. The stronger waveloc bolts surely help but ideally, stock 289/302 rods need to step up to the oddball 11/32" arp bolt sizing since 3/8" size upgrade is too big a jump.. actually eats too far into the big ends ID and ultimately diminishes the big ends integrity. Going too far basically just changes it to where the cap breaks before the bolt itself ever reaches its fatigue limit or failure point. lol Not saying that you will in fact have issues here.. because I too have pushed my luck, even with stock, parts WAAYYY past stupid more times than I would care to admit.. only that myself and others have stretched many fancy bolts used for the sake of stopping and starting atrociously heavy older designs of forged pistons. Might not ever cause a failure at all.. but when you measure the bolts free length and/or try to easily slide the caps off the bolts at teardown.. you'll know something's up. The 400 horse club being added to rpm plus heavier reciprocating weight equals more stress than is typical is the main point I'm getting at here. These adjustable variables are why it's nearly impossible to put rpm or horsepower limits on factory hard parts. I believe you likely still have more than ample margin built in here.. just be cautious with the tune and make damned sure you have a rev limiter keeping your right foot in check, is all. Interesting build and I'll be watching for sure. Who did the porting work on the heads and manifold?
Hooker 6208 1 3/4in super comps will really wake that thing up,those 1 5/8 in Hedmans I don`t think will cut it.
Pure drag duty?.. maybe. I could see running a step style header here but can also easily imagine that running full 1.75" primary pipes wouldn't help such a small motor where it's most needed. Especially true since there isn't nearly enough room to really make them long enough to help preserve low to mid range torque(2,000-4,000'ish rpm). Not to mention that larger header would most definitely need a merge collector to reduce reversion during overlap. Basically all I'm getting at here is that typically speaking, road racers need some added "pipe time" down lower in the rev range too. Dry intake manifold or not.. you usually never want reversion skipping around between cylinders in a common plenum such as this. A smaller primary pipe will work to prevent this and help to fatten/broaden up the rev range(more average power) even though peak power may be down slightly. 1.625" OD primaries(about 1.5" ID) have also been used on many a 500+ horse engine through the years. Because it makes a difference in what's considerd optimum, I also have to wonder.. what trans and gears will be used here?
The issue with 3/8 rod bolts was definitely something I was concerned with but I wasn't aware of an 11/32 alternative at the time. All of the porting and head work was done by myself at the direction of a family friend and 40+ year head building veteran. The transmission I'm going to be running is a C4 manual VB, foot braking/line lock on a 3200 stall converter, currently rear end is set up with 3.80 gears and a mini spool although I'm looking into stepping to either a 4.11 or 4.62 gearset. Although cruising at 38oo rpm on the freeway doesn't really seem to appealing at this time. As far as NHRA requiring 1.75 around, I was talking about requirements for a full cage 8.50 spec. which as far as I can tell depends on the number of bars being used. With the season getting as close as it is, I'm not sure that I will have time to complete the cage prior to the start and may have to post-pone construction. Hopefully it won't be an issue to start. At the current point in time, I made the jump and swapped intakes back to carb trim and will be running a holley 650 DP, HEI, and a performer intake I found in the shop until I manage to work out some kinks in my FI setup. Trying not to miss out on early points even if I'm getting knocked out first round. -Ryan
