| Author | Message | ||
     Ricksbuell |
Was- wondering i've got some parts to install and wondered if anybody might know what kind of horse power it might make? Here goes- 10-over pistons & cylinders- thunderstorm heads-jims lifters-adjustable pushrods-andrew n4 cams-42MM mikuni carb-s&s intake- screaming eagle coil and screaming eagle race module 6500rpm.this whole lot of parts cost me a grand .was this a good price? this was all on a drag sportster very briefly only a couple of runs. Do i need all this or just parts of it? I just want to make my lightning to go crazy fast.Oh yeah and a pingle wheelie bar. Thanks and any info would help . | ||
| Alessio66xb12r |
...a grand ...means 1000 american euros (also called dollars)..right ? very GOOD price . if those heads were on a drag motor maybe they are flowed and with bigger valves and upgraded springs-guides-locks-seats .....and which kind of cyl.-pistons ?? thunderstorm ? which lifters...hydro-solid ? we need some more info to give you an answer.... anyway good price . regarding the heads i don't know if a drag racing set has the same characteristics of a race-track or hot-street heads. give us details and the GERMAN "ACCADEMIA" will answer you ....sure. | ||
| Ricksbuell |
To be more specific the heads are flowed with bigger valves springs, locks,seals,all updated. The cylinders are harley -davidson bored 10 over ,and the pistons are custom made.The lifters are rollers.I just received an e-mail from the guy who sold me these and he said he found out they paid close to a thousand just for the pistons. hopefully this will help answer my h.p. question.THANKS RICK | ||
| Panic |
"they paid close to a thousand just for the pistons" I've been playing with engines for over 40 years, and that price was pulled right out of his rectum, easily 3 × the actual price. "The lifters are rollers" And so are yours, and every lifter H-D built in the last 80 years. Depending on how much work was done to the heads, and by whom, and what condition they're in, you may gotten a good deal, or not. | ||
| Alex |
Giving estimated HP numbers just from a description of parts is pretty similar to guessing how the weather will be on 26th of March 2010  . There is much more involved, I´m afraid. | ||
| Ricksbuell |
Thanks for the replies , I don't expect you to give exact numbers ,just an estimate of what it could be .If it's not worth my effort I'll put the parts on a shelf. Someone else out there has got to have done some of the mods & has an idea of hp & maybe what cc,s would be? I don't want to trouble anyone I just don't want to ask a dealer.Thanks Rick | ||
| Alessio66xb12r |
thunderstorm flowed heads and matching wiseco pistons is an upgrade respect your heads/pistons set . also is mikuni 42 , s.e. module and cams . if lifters are solid type forget about in a street engine ( my opinion). you know to do it right you MUST balance the crank . better if you will use a roller rocker arms on your new heads. .....with those things you will gain some power (3 5 10 hp who know ?) and a better curve if everything is done properly.....but it was said un possible give you an answer from a description of parts , many things involved : conditions , comp. ratio , tuning , exc. not sure ...010 more means 1214 cc . who is going to rebuilt ?? bye Alessio | ||
| Ricksbuell |
Thanks ,Alessio- That is what I was wanting to know .I am wanting to install thunderstorm heads / pistons .Did not know about balancing crank.I have n4 cams- 42mm mikuni.I bought this stuff from a guy who raced sportsters and a friend who stunts on firebolts and drag races a sportster is going to help with the build.I'm just trying to learn as much as possible as to what to do and what to buy.The parts I got were a good deal everything is almost new and very clean.I jut want to do it right.THANKS RICK and thanks about the cc,s | ||
| Alex |
Rick, one of the most important part of a performance engine is the set of heads. As You have reworked heads I would suggest to go to a professional head porter, have him inspect the heads and put it on the flow bench. He will be able to tell You if the heads are suited for the application You want to build. | ||
| Alessio66xb12r |
Alex a question for you (and for everybody knows). when i built my 88 i used my stock heads reworking the chambers and the ports , i used a cp pistons set that has the 15° dome , piston's dome start after a little flat spot , i think you know perfectly the profile of those pistons . now my question is this : can i use a set of thunderstorm heads without reworking the chambers on my engine ?? i think the thunderstorm chambers match the profile of my pistons. thank's for any input. bye Alessio any input | ||
| V74 |
hey alessio are roller rockers worth getting as over here they are over £400 a set,i have always been intrigued by these and wanted to know if they gave any measurable increase in performance or is it just all sales hype ??? | ||
| Alessio66xb12r |
to V74 the proper valvetrain setting is a very important step not only for performance but for engine life to , roller rocker arms will NOT give you any improvement in performance but they will give you a less stressed and maybe longer life in the valves guides area . good to use them with hotter cams good to use them even with stock cams ( my opinion ). bye Alessio | ||
| Alex |
Alessio, the CP pistons that come with the Revolution Performance 88 kit are designed for Thunderstorm heads. The given CR of 10.5:1 is based on the Thunderstorm´s 66cc combustion chamber. So YES they will fit those heads as they are made for those heads without combustion chamber work. There´s only one thing to remember: the Thunderstorm head´s combustion chamber is a rough cast (it is not machined) so the actual squish distance varies from head to head. If You want a tight squish machining of the squish area is required. Afterward You will have to deck the heads to bring the squish band back to stock size in diameter. Then You need to remove material from the combustion chamber to get back to a streetable CR. From my personal experience: I already used the 88 kit with stock Thunderstorm heads (not really stock but stock when speaking of the squish area of the combustion chamber). Regards Alex | ||
| Alessio66xb12r |
thank you Alex this is the bad new , honestly i suspected it , i ended up my chambers at 69 cc 69.5 cc and with a .35 thick head gasket i found out ( considering dome ,valve pockets , ecx.) with the piston at TDC at the perfect edge of the cylinder ...10,65 10,90 COMP.RATIO.(cold) ....don't ask me how . i'm sure i have a perfect squish on the flat spot around the piston /head face (.35) when the dome start ...start my fault 15° on piston dome,and somewhere more than 20° on the heads ....the bike runs really fine now , maybe i'm losing some h.p. i know . i know also what to do when i'll put my hands on the heads again ( report material or buy an used pair of thunderstorms and rework them) .....First experience. thank you very Much. bye Alesio |
