Escort 1600 Posted July 5, 2012 Share Posted July 5, 2012 Doing it on the Cheap 1300 pistons are an easy way to gain more compression but you dont get as good burn that you get with the 1600 pistons as the combustion chamber in the 1300 pistons is offset to one side of the piston crown so dosn't fill as well + the 1300 pistons have a thicker crown which also makes them heavy. You get best results from decking the block and turning down the piston crowns to suit. You will also probably find you will need to pocket the pistons to give some clearance to the valves if you ar running a hot cam. Various tuners have different Ideas regarding the flat heads and chambered heads and there are many arguments for and against each. I'm running the chambered head on mine with big inlet valves, 1600 sport exhaust valves, 10:1 compression using 1600 pistons and decking the block, standard twin throat weber carb BCF3 cam and after a good tuning session on the dyno its been sweet reliable and drivable motor at 110hp, Ive put alot of cars to shame that are claiming much bigger power than what mines making! Quote Link to comment Share on other sites More sharing options...
krindaryl Posted September 9, 2012 Share Posted September 9, 2012 Guys what horsepower would a 1600 kent with flat head having 43.7mm intake valve and 35mm exhaust valve,kent 272 cam.specs are 304/12.8mm lift,I'll be using flat top pistons,datsun L20 crank and fueling is threw 48mm throttle bodies Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 9, 2012 Share Posted September 9, 2012 Guys what horsepower would a 1600 kent with flat head having 43.7mm intake valve and 35mm exhaust valve,kent 272 cam.specs are 304/12.8mm lift,I'll be using flat top pistons,datsun L20 crank and fueling is threw 48mm throttle bodies Carbies or EFI? The use of "48mm throttle bodies" could indicate ether, approximate compression ratio you expect will help to. Tuned headers, Inlet? Other head mods? 10-1, headers, flow work, carb around 170hp ATW. 11-1, headers, flow work, EFI around 190hp ATW. More with a good combo assuming pump gas is used? Please correct me if I'm wrong. Will be one angry engine and you will be getting very close to the limits of the block, keep up the good work. I do have a couple of comments which you might want to look into. Not sure the L20 crank will be up to the 9500RPM the 272 will allow. I hope those "Flat top pistons" aren't 1300 ones. They will fly apart, Forged will be needed. You will need to spend up large on flow work to get enough for the increased demands this combo will create, could be time to think Lotus head. With that much lift you are going to punish the valve train big time and a bit more than pocketing the pistons may be required. I think you will also have to recess the valve springs to let the valve open that far not mentioning retainers, followers, push rods etc none of which will live much past 7K if stock. An oil cooler will be needed and dry sump could be an option to maintain reliability at this level of tune. Don't expect it to last very long, you will be lucky to get a season of racing. A3, A4, 254 or 262 might be a better option if you plan to use such an animal on the street, the 272 is a very big cam and will have nothing under 4K on the rev counter and I do mean nothing. It's not called the "Ultimate" for no reason. Quote Link to comment Share on other sites More sharing options...
J-W-G Posted September 10, 2012 Author Share Posted September 10, 2012 Keep in mind that 200hp n/a has never been achieved with a kent. Has come very close. Id say that youd get to say 160 to 180 bhp atw Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 10, 2012 Share Posted September 10, 2012 Keep in mind that 200hp n/a has never been achieved with a kent. Not with a OHV head at least lol Id say that youd get to say 160 to 180 bhp atw I'd say he's not going to get BHP anywhere but the flywheel... Quote Link to comment Share on other sites More sharing options...
J-W-G Posted September 10, 2012 Author Share Posted September 10, 2012 Keep in mind that 200hp n/a has never been achieved with a kent. Not with a OHV head at least lol Hmm peaked my interest Raizer! Has an OHC head or say a 12 or 16 valve head been fitted? Link it please! Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 10, 2012 Share Posted September 10, 2012 Not talking about his, but quite a few of the BDA family engines put out over 200bhp NA. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 10, 2012 Share Posted September 10, 2012 20 years ago I was getting 160hp ATW with an A3 11-1 and twin 45's on Av Gas from a 1600. Had a shit load of other goodies in there to but that's for reliability not more hp. Surly some one must have reached 200ATW with a 8 valve NA stroker combo. Does a 50hp shot of NOS count or is that cheating? LOL. Quote Link to comment Share on other sites More sharing options...
Escort 1600 Posted September 13, 2012 Share Posted September 13, 2012 A really good crossflow with big valve head, side draught carbs, forged pistons and rods ect you would expect to make around 160hp at the flywheel. Some big budget builds with alot of trickery make over this but they are big budget. 160hp crossflow engine aint slow! Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 13, 2012 Share Posted September 13, 2012 When I did mine a huge amount of $ was spent in development and head work. What we found was the total flat top pistons hurt the hp more than small valves did. A shallow elliptical bowl with the deepest point towards the spark plug side in the top of the piston with the head shaved to get the compression right improved output way more than the big valves did. Sort of a wedge / hemi combo when the head is done as well. We even offset bored the valve guide holes to get as big as possible valves in and I have seen some that plugged them and re-bored them to create an angled valve to get straighter ports. The shape and shaft size of the valves can make a difference to. I used some that where almost flat on the port side and had a tapered shaft. Frigin expensive little suckers but made an extra 5 hp with just that mod. True race motors also use a very narrow valve seat that is unsuitable for a road engine and that helps output as well. Valve grinds required about twice a season. Reductions in the piston and con rod weight by using forged bits also saw some surprising increases in hp. Most of the work I did was in the combustion chamber once the head had the flow required in an attempt to get a clean fast burn throughout the chamber, that's something that takes time and money, about 10 sets of pistons and 20 heads where consumed to achieve the wanted results and a dedicated team behind you. Quote Link to comment Share on other sites More sharing options...
krindaryl Posted October 4, 2012 Share Posted October 4, 2012 I didn't keep updated with the formula because I was building my street 1600 kent with v6 intake valves,BCF2 cam,32/36 weber,1300 pistons with a 2mm decked block,polished conrods,polished crank,a balanced bottom end...a 5speed sierra conversion with a 3.89 diff in my mk1 escort and suprisingly the engine made 109whp which I was impressed with hopefully I'll take it too the track and tell you guys sometimes...Those flat top pistons aren't 1300 pistons they actually flat top pistons which I'll get custom made...and the conrods will be forged..the crank will be knife edged to loose someweight...the block will get a strengthing liquid which I'll import...I'll use hardened V8 pushrods...roller rockers,I'll put all the good stuff in this engine...its not going too be something too joke around...I'll use this engine for 1/4 mile drags only and maybe some saturday night racing....lol.. Quote Link to comment Share on other sites More sharing options...
krindaryl Posted October 4, 2012 Share Posted October 4, 2012 I was thinking a compression around 12.5:1...the head will be ported and flowed too the max....I was hoping 200hp from that kent...that motor would have been built properly with all the right components Quote Link to comment Share on other sites More sharing options...
krindaryl Posted October 5, 2012 Share Posted October 5, 2012 Guys...I've started collecting parts for my kent build...I already got a set of ITB's which I'll be running EFI...I also got a complete engine just waiting to get worked on...I got my whole fueling setup...like management,fuel injectors which is 750cc primary and 350cc secondary,fuel rails,my manifold and my crank trigger setup..now I just need to collect all my parts then everything can get machined...I'll also swirl cut and polish my valves,3 angle valve seats,bronze valve guides....Hope it can put my dads 300hp duratec and 200hp 4age too shame... Quote Link to comment Share on other sites More sharing options...
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