Title: what heads size?? Post by: speedwell on March 25, 2015, 18:27:58 pm hi ,
i'm collecting parts for my engine 82x88mm i've got an 82mm okrasa crank with carillo rods(porsche journal) and i've also 88mm cima pistons/cylinders now i would like to order my heads , but i need to know what valves size i will have , i've 48ida on race trim short manifolds and what rockers arms ratio can i've , ??? my engine would be more for a street use than dragstrip thx in advance for yours advice fabs ;) Title: Re: what heads size?? Post by: Zach Gomulka on March 25, 2015, 18:43:27 pm Nice parts :)
Some 40x35.5 heads would suit it very well. What RPM range do you want the engine to work? Edit: If I was you, I'd build it simple since you aren't trying to set the world on fire ;) Engle 120 cam, stock rockers, 9:1 compression. Title: Re: what heads size?? Post by: speedwell on March 25, 2015, 20:43:31 pm Nice parts :) 40x35.5 was the size i was thinking Some 40x35.5 heads would suit it very well. What RPM range do you want the engine to work? Edit: If I was you, I'd build it simple since you aren't trying to set the world on fire ;) Engle 120 cam, stock rockers, 9:1 compression. yes , don't want to set the world on fire , but i want to play with. my engine sometimes , at the red light , not doing some runs on the street , but just beat some rice rocket or gti or some kind of car like this , and may be going on the strip sometimes . no idea about the RPM range , i've now idea how an engine like this can go Title: Re: what heads size?? Post by: Zach Gomulka on March 25, 2015, 20:58:22 pm Well, as an example the 1915 I built for Asshull uses a Engle 120 with 1.25 rockers (and 40x35.5 heads with IDA's). It will pull to 7,000 rpm easily and has very drivable torque. It would probably run low 14's at the track. Your engine will produce even more torque. More duration means higher RPM power, with less torque in the lower RPM. You could use an Engle 125 for more mid range and top end power, but will you use it or need it??
I would personally keep valve lift below .500", and stock 1.1 rockers for simplicities sake. Title: Re: Post by: speedwell on March 26, 2015, 07:56:05 am Ok thx zach
Title: Re: what heads size?? Post by: cedric on March 26, 2015, 10:19:31 am Why not fk7.. Its a torq cam...i buy first my heads go to a flow beanch and then order my cam to te spec of my heads...
Just my 2 cents Title: Re: what heads size?? Post by: Jeff68 on March 26, 2015, 13:09:09 pm Those parts are a very strong foundation to build on. What everyone said above ^^ is great advice. If you decided to go a little wilder the K8 is a tried and true cam. I have a similar engine in my car. When I was picking the cam I kept going back and fourth between the K8 and K10. I picked the K10. You would have to use ratio rockers though. My engine is 82 X 90.5 with ported heads 42 X 37.5 valves and 48 IDA's. Have fun!
Title: Re: what heads size?? Post by: nicolas on March 26, 2015, 18:08:56 pm fk8, works great, does everything, uses 1.4 rockers. ;D
Title: Re: what heads size?? Post by: nicolas on March 26, 2015, 18:10:49 pm besides if Fabs means 'modest', see what rpms he pulls in his stock 1600 with IDF's….
"nicolas, it doesn't pull very good at 5000 rpms" ::) ;D ;D ;D Title: Re: what heads size?? Post by: speedwell on March 26, 2015, 19:47:26 pm besides if Fabs means 'modest', see what rpms he pulls in his stock 1600 with IDF's…. "nicolas, it doesn't pull very good at 5000 rpms" ::) ;D ;D ;D ;D ;D ;D ;D ;D ;D Title: Re: what heads size?? Post by: Udo on March 26, 2015, 22:25:15 pm 42x35,5 heads hand oval ported and FK8 with 1,4 rockers or T7E8 pauter cam
Udo Title: Re: what heads size?? Post by: nicolas on March 27, 2015, 17:42:59 pm 42x35,5 heads hand oval ported and FK8 with 1,4 rockers or T7E8 pauter cam Udo just out of curiosity, why chose a 42 intake valve over a 40 with the 35,5 exhaust valve? i would assume the 40x35 combination would work really well along with the 88 cylinder even better then the 42. what is you thinking behind this choice? Title: Re: what heads size?? Post by: Udo on March 28, 2015, 16:45:21 pm A 42 would make more power. but 40 is ok too
Udo Title: Re: what heads size?? Post by: nicolas on April 01, 2015, 16:35:34 pm A 42 would make more power. but 40 is ok too Udo OK, thank you. |