Tyler06 266 Posted March 28, 2014 Hi all. Im gonna build a new donk for my ute and T5 it instead of the 302 and toploader its running now. I have some new 377 pistons and 5.7 chev rods but I cant find a crank anywhere. It seems that no one wants to offset grind one either. Im thinking of running a f246 cam and TFC mani with 750 dbl pumper. Msd dizzy and 6al. Ive got good extractors and half a dozen T5s I can break lol. Heads I am thinking just 2v casts with the usual port work and 4v inlets, roller rockers etc. But I do have a roller cam conversion made by howards. Just looking for hints and tips etc maybe some guesses on power I can make. Oh and where I can buy a crank to suit lol Cheers Chris Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 28, 2014 you can't buy a 377 crank, unless someone has already offset ground 351 crank thats how you make a 377 find another machinest. should be no issue to do. cam is a well known performer, F246 will make 480-500hp with decent heads. use a TFC manifold, top quality manifold, work extremely well. head wise, you want them to be flowing 240+cfm from .500 upwards on the intake and 180+cfm @ .500 upwards on the exhaust, at least. that requires more than valves. that means port work. you'll probably spend $700-800 in porting to get them above that. can reccomend someone if you are in Vic. other option is a hyd cam, or hyd roller, if you wanted virtually maintenance free. 1 XTREME KARTS XF reacted to this Share this post Link to post Share on other sites
Tyler06 266 Posted March 28, 2014 Cheers mate I have a guy I will use for my porting ;-) TFC manifold I already have and I would love maintenance free. Any suggestions? Ill try another machinist. Share this post Link to post Share on other sites
gerg 10,871 Posted March 28, 2014 That kind of machine work is definitely possible but not cheap, I'm sure if you dig around, you'll find someone. Be prepared to pay more than you would just buying one as it's a lot more involved than just a grind and micro polish. It will need some serious balancing too. Luckily for us Ford guys, chev-sized rods are as common as dog's balls. It's also handy that Clevo big ends are massive with plenty of meat to offset-grind down to chev size. Share this post Link to post Share on other sites
PRO250 1,506 Posted March 28, 2014 ring prostroke there old school and i bet can still do a offset crankshaftF246 is a big street cam in a manual mines big and border line as a manual anything bigger it would be a turd to drive i think ive driven dans f246 engine and as a manual theres no way id want to own it 1 Trev Vaa reacted to this Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 28, 2014 lunati 62505 hyd tappet cam would be bout 15hp/15ftlbs down at a guess Camtech CT2021-49904-110 hyd roller would be almost the exact same as f246. maybe a bit less torque. pft, daves a pussy , f246 is beautiful on the street! love them, imo perfect weekender! peaks around 6500rpm grouse fun to drive! btw you will need at least 3.5 diff gears. comes down to the person at the end of the day though, you may hate it or love it. i've driven plenty more radical cammed motors with manuals and autos. drove a 302 that shifted at 7800rpm once, i loved it. i love big cam motors, i'm quite comfortable with a comp 308R on the street, i have no issue driving it at all. awesome fun to drive. Share this post Link to post Share on other sites
Tyler06 266 Posted March 28, 2014 I need the offset crank so maybe I should get that first lol Share this post Link to post Share on other sites
ILIED 316 Posted March 29, 2014 Just check the price on recon the heads and porting, it may be better to just buy some alloys Cheers mate I have a guy I will use for my porting ;-) As for the Cam argument, mine in my ute is a bit smaller, its a Comp 280H and its fair soft. My ute is effectively a 3 speed cos ya just dont use 1st. I'm running a 3.5 diff and 33" tyres and I really wouldnt mind something a bit angrier, oh, my ride is like 2.5T so I imagine it would be much cruisier in a Falcon. Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 29, 2014 chaise is right, might only be a few hundred difference.... in which case definitely worth going the alloys. Share this post Link to post Share on other sites
blownxd393 25 Posted March 29, 2014 dont fit 4v valves to the inlets of the 2v's mate. your doing more work to go slower the f246 works well with the 378ci and especially on the street but the f246 works much better with 4v heads i found. in all honesty, i relise you have half the parts but it makes more sense to build a 383 0r 393 and most proberly cheaper in the long run. what pistons do you have trws ? 1 Trev Vaa reacted to this Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 29, 2014 i agree with everything you said blownxd393 bar the 4v comment. ported 2v's that flow properly are much nicer having driven both i find the 4v's are boggy down low. but you need the 2v's to be able to support the flow required. a simple exhaust valve change will not do, you will need to do port work. the advantage to ported 2v's over standard 4v's is the port velocity and the lower lift range on the 2v's if ported correctly will well outflow the 4v heads up to .550" lift (i have the flow figures of my new heads to reference off) .600 and above the standard 4v head will outflow ported 2v's unless major port work is done, at which point it would be cheaper to buy alloy 2v's anyway. @ .550 lift 250cfm on intake and 200cfm exhaust is achievable quite easily on a 2v head in the right hands. (mine flow 243 and 194 at .550") Share this post Link to post Share on other sites
blownxd393 25 Posted March 29, 2014 i agree with everything you said blownxd393 bar the 4v comment. ported 2v's that flow properly are much nicer having driven both i find the 4v's are boggy down low. just to clarify mate, was this particular combo with the 4v heads a 351ci or 378ci ? only reason i ask is i had ported 2v heads on my 378 with a 246 and switched to 4v cc heads same cam with zero lathargic bottom end issues. dont get me wrong i love my 2v heads. i could understand if it was a 351 with your comment. Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 29, 2014 383ci on the 4v's 377 on the 2v's again it comes down to what the 2v's can flow.... like i said they do require a proper port job. do you remember what your 2v's flow? Share this post Link to post Share on other sites
blownxd393 25 Posted March 29, 2014 Not sure what they flowed. I ported the oc 2v heads myself years ago but they are faced to 60cc. Still got them on shelf. What comp and cam you have on the 383 ? Seems strange to me your bottom end issues and even with those cubes should of woken it up earler I would of been thinking. Share this post Link to post Share on other sites
PRO250 1,506 Posted March 29, 2014 Im sure ive showed this a zillion times but it seems more fitting then ever LOLstock 351 bottom end f246 2V open chamber heads no port work at all i shit you not. this thing went 12.0 off the trailer at 108mph 10km on the clock never on the rollers how that for having a go LOL arr booooo no wes i will say this thing was a shit street car fun for a frap around the block but no way id have it in a car i drove a lot Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 29, 2014 both motors run similar compression and f246, id say your lack of power was due to what your head flowed. the physical size of a port on a 4V reduces airflow velocity so much so it effects engine breathing, loosing bottom end, thus the bog down. yeh i remember you talkin bout that ute dave. fyi dont ever buy a motorbike you will hate the whole no power till 8000rpm thing. 1 bear351c reacted to this Share this post Link to post Share on other sites
blownxd393 25 Posted March 29, 2014 Where did I say lack of power on my combos ? Iam bit confused now sorry cob. Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 29, 2014 sorry my mistake, you just said it was nicer on the street with the 4v's. my bad. Share this post Link to post Share on other sites
blownxd393 25 Posted March 29, 2014 sorry my mistake, you just said it was nicer on the street with the 4v's. my bad. All good mate, The point I am trying to make is that the f246 and 378ci on the street is no slouch down low... From my exsperiance. Just to add I also used to have a f246 in my tunnel rammed 4v xd also 378ci 12.2-1 comp, 3.5 gears and a UN matched 3k all fast stall . Again the myths of no bottom end power was put to rest even with the ram and twin 750cfm carbs. Carl 1 Trev Vaa reacted to this Share this post Link to post Share on other sites
gerg 10,871 Posted March 30, 2014 I think what we can gather is that 4Vs can make power with less cam. I've read posts about how you can't approach a 4V build the same way you would with a SBC or Windsor. I think if you stick to the philosophy of the original engineers who designed them, you cant go wrong. GTHO cams are not really that wild by today's standards (probably about halfway down a cam catalogue from mild to wild), but Hoeys are known for punching out a factory (unofficial) 370-380 hp in their day. It's likely that that comes mostly from the head design. If you go shoving a cam in that makes good power on a 2V, it will be a dog in a 4V down low because the ports are so big and will lack velocity. I guess you could sum it up by saying that 2Vs make power with long gulps of air, 4Vs make it by using big nostrils. 2 bear351c and Trev Vaa reacted to this Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 30, 2014 agreed, f246 is extremely driveable all through the rev range. Share this post Link to post Share on other sites
Butcha 111 Posted March 30, 2014 Compression ratio plays big part in how doughy a cam is down low. The extra cubes will bring cam operating range down a few hundred rpm. Get your headflow, timing and compression right and grandma will still take it to bingo no worries Share this post Link to post Share on other sites
blownxd393 25 Posted March 30, 2014 Compression ratio plays big part in how doughy a cam is down low. The extra cubes will bring cam operating range down a few hundred rpm. Get your headflow, timing and compression right and grandma will still take it to bingo no worries This is reason I asked what comp he had. Run 10 to 1 with the mighty trusty old fashion f246 and I will be a lethargic slug until Mr velocity wakes up ! Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted March 31, 2014 nah both were around 11:1 plenty of comp Share this post Link to post Share on other sites
blownxd393 25 Posted March 31, 2014 nah both were around 11:1 plenty of comp i take it yours were oc 4v heads then yeah ? Share this post Link to post Share on other sites
