Always considered "bolt-ins/ons" to be the Big-4, Carb/Intake/Cam/Headers, since I was a pre-'teen. There were no killer heads to bolt onto anything, W2's for a SB, but I didn't know anyone personally who'd even seen a set back then...at least not in person. Now.....whole different ballgame, and yet I see people complaining there's not as much/it costs too much vs Chebby junk, get over it & be glad there actually ARE the bolt-ons to do a WAY over 300hp 'teener.
300 HP out of a 318, is it possible with bolt ons?
- Thread starter madjak.06
- Start date
-
I can agree with that. It's like Mike was sayin, if you include camshafts as a "bolt on", where does it stop? Cylinder heads too? I would say yes to the heads maybe if "all you had" was a short block.
I don't have any numbers for comparison but I took a fresh .030 over stock 318 that I pulled out of a Dodge Aspen wagon, purchased from an insurance company salvage auction and dropped it into a 1970 Dart GT, drove it like that, with the 2 bbl and original 1970 points ignition until it popped a head gasket. Then I put on a pair of 340J heads and matching cast iron intake with a big old thermoquad of unknown origin. If that thing didn't make 300 hp, it had to be damn close, night and day difference, even with stock exhaust manifolds it still went like a raped ape!
she doesn't even need a light.
michiganpat
Well-Known Member
magnum heads, 4bbl, headers, and a cam in the [email protected] range should get you there and still be plenty streetable.
michiganpat
Well-Known Member
suppose I should qualify that as at the flywheel. 300 HP at the rear wheels would be more like 360 gross at the flywheel, which might still be possible with a stock short block, headers, something like an RPM air gap, magnum heads, and a cam in the [email protected] range. this is a good, but older article: https://www.motortrend.com/how-to/mopp-0409-318-engine-build/
personally, I'd just start with an '85-up roller or magnum engine, and look at doing a reground roller cam. it allows for more aggressive ramps, and longer .200" duration for the same amount of .050 duration, getting more air in while also giving better street manners and low end...
personally, I'd just start with an '85-up roller or magnum engine, and look at doing a reground roller cam. it allows for more aggressive ramps, and longer .200" duration for the same amount of .050 duration, getting more air in while also giving better street manners and low end...
junkyardhero
Well-Known Member
i see this motor build referenced time to time-- in fact it was mentioned up thread and i commented on it-- and what people fail to realize is that while yes, it is a stout piece, don't just look at the lofty numbers. look at where the power is made 4000~6000 rpm
i've built this motor, exactly this motor, twice. if i was looking for 300hp and a nice street driver, this isn't where i'd start, especially on a budget.
michiganpat
Well-Known Member
the engine I built about 15 years ago for my 5th avenue was the stock block, reringed with moly rings, thin MP head gaskets, magnum heads with a fresh 3 angle valve job that I did some bowl porting and gasket matching, 600 cfm edelbrock on an RPM air gap, hedman headers, stock magnum lifters and rockers, and had the LA roller cam reground by bullet cams to their HR256/326 on the intake (256 adv/[email protected]/[email protected]) and I can't remember what lobe on the exhaust, maybe the HR267/325, and that engine ran GOOD. IIRC the stock LSA on the factory cam was 112, I think I installed it 4-6 degrees advanced (106-108 ICL)...can't remember what springs, maybe hughes 1110? I remember I limited my lift so I didn't have to have extra machining done either on the valve guides, or it was a limit I could handle before coil bind....it was a long time ago....anyway, that engine had great street manners and power from off idle to about 5500 RPM, and ran as strong as the stock long block 360 with the same induction system and a comp XE262 flat tappet, which it replaced, but got another 5mpg....
if I remember right, the .2" lift duration of that roller lobe was actually the same or a few degrees bigger than the XE262.
Be ALOT quicker than doing a straight 8 vehicle !!!
Dan the man
Well-Known Member
I Don't think that the year of the engine makes any difference as far as the compression height goes as all of the replacement pistons are the same. I've never seen a selection of pistons for a particular year engine.
Dan the man
Well-Known Member
300 horsepower at the flywheel put your car in the high 11's? That's roughly 240 - 255 to the ground. What gear ratio and stall speed converter did you have? I've been told that it takes 300+ horsepower at the wheels to get out of the 12's. But I don't know this as a fact.
Dan the man
Well-Known Member
Back in the day, we all considered bolt ons to be a 2 barrel to a 4 barrel swap, better air cleaner assembly, headers and true dual exhaust, electronic ignition conversion and a curve kit along with better rotor, cap, wires and plugs. We also would relocate the coil to help keep it cool. Also cool cans were sometimes used. Some guys would even take the carburetor apart and deburr the inside and remove the choke horn. We was all kids Back then working were ever and so we had to get our cars to run as good as we could with what we had. One guy even put a torque converter from a powerglide in his turbo 350 as that was a poor man's stall converter. We had loads of fun and never had a fortune in our cars. What was cool too is that everyone helped everyone it didn't matter what brand of car you had.
dirty white boy
50 yr old Juvenal delinquent
well,..depends!! 300 hp wil get a 2800 lb car in to 11s, but a 3600 lb car gonna need more hp! wallace has a calculator to figure your power to weight ratio....DWB
junkyardhero
Well-Known Member
read the rest of the thread, it's all in there.
4.xx gears and a monster stall with a bunch of tire, and a very well tuned chassis, along with a good driver.
Dan the man
Well-Known Member
Sounds like a good combination
-
