Lahsak80 1 Posted May 31, 2020 Hi All, I was wondering if it is possible to obtain decent power from bolt-on mods, and parts that do not require any machining work? If anyone has done this, what kind of power have you achieved? The aim is not for any race/track purposes, just want something with guts when needed. Thanks. Share this post Link to post Share on other sites
CHESTNUTXE 7,260 Posted May 31, 2020 take factory fan off 20hp gain Share this post Link to post Share on other sites
Lahsak80 1 Posted May 31, 2020 That's cute, was also thinking of bolting on those ebay turbo whistle exhaust tips, apparently another 15hp from each tip. Share this post Link to post Share on other sites
gerg 10,871 Posted May 31, 2020 Nah Chestnut's dead right. Dyno tests are proof of that. Go electric fan as they only come in when needed. Cuts the horrible noise too. Bolt-on mods only get you so far, and depends on where you're starting from. If you have the standard 4 barrel manifold and carby, they're both good for 400 HP, so no decent gains in swapping them for performance versions. Biggest things holding back a stock 351 are cam, exhaust and heads. If you don't want to take the heads off to shave them (compression), change the valves and retainers (single piece and single grooves) and do the ports (flow) , then that narrows it down to exhaust and camshaft, which in this case is limited to something around 0.500" lift on stock valve springs and probably 220 duration at 0.050", given that you're working with stock compression. So... Piss off the mechanical fan, bolt on a set of extractors and shove in a mild cam/lifters/timing set and that's about all you have if you don't want to open up the engine. Sent from my CPH1607 using Tapatalk 3 Thom, motoSycho and bear351c reacted to this Share this post Link to post Share on other sites
winton 399 Posted May 31, 2020 1 hour ago, Lahsak80 said: That's cute, was also thinking of bolting on those ebay turbo whistle exhaust tips, apparently another 15hp from each tip. Haha, i find this amusing Share this post Link to post Share on other sites
bear351c 10,260 Posted June 3, 2020 .......and find some 302 CC heads. ......and change the ignition system to ICE or similar. 1 gerg reacted to this Share this post Link to post Share on other sites
Lahsak80 1 Posted June 4, 2020 On 6/3/2020 at 12:25 PM, bear351c said: .......and find some 302 CC heads. ......and change the ignition system to ICE or similar. Yeah was def looking at the ICE ignition, local product with good support. With regards to the heads, was planning CHI heads, or is that a waste if you consider the gains achieved with 302 heads. Share this post Link to post Share on other sites
Lahsak80 1 Posted June 4, 2020 On 5/31/2020 at 5:15 PM, CHESTNUTXE said: take factory fan off 20hp gain Sorry ChestnutXE, thought that you were taking the piss with that comment. Will change the fan for sure. Share this post Link to post Share on other sites
bear351c 10,260 Posted June 4, 2020 No, not at all. CHI or AFD will work wonders, just wasn't sure of the budget. Looking at around 2 grand each, I reckon. The weight saving over the front wheels makes a difference too.! Change to alloy heads, alloy water pump, alloy intake manifold and radiator, would be close to 50 kilos. 1 gerg reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted June 4, 2020 Yeah clevos are a heavy lump... Around 250 kg dressed.By bolt-ons, I wasn't sure of how far you wanted to go and still consider it bolt-on.CHIs are definitely bolt-on power. You would gain simply by having them and nothing else (except roller rockers, which these heads need regardless). However to take full advantage of their potential, you really need a roller cam, decent intake, big carby, headers, it all starts to add up. Sent from my CPH1607 using Tapatalk Share this post Link to post Share on other sites