Hey there guys i am going to do a motor buildup very soon, either a 350 chev or a mopar 340, but either way i want to build an engine that will give me some power to play with but will have low enough compression to run on pump gas...i am a university student and need to save every penny i can...i do have basic knowledge on building motors and the parts involved, but does anyone have any tips on how to build one that is low compression but makes anywhere between 300-450 hp (its gonna be a daily driver)? also, if there are any really good general engine building guides out there that would help me with building a low compression motor, or just help me in motor building in general, please let share the titles....thanks in advance fellow gearheads \m/  

Is there not anyone on this message board that can help me with this at all??? please guys i need a hand here and i would greatly appreciate any advice...  

ok this is for a chevy 350 build up I would use a lunati streetmaster cam kit P#07104LK, a set of full length headers,a set of summit racing heads P#SUM-152123,600CFM holley carb.,and a rebuild kit with flat top pistons. Also you might want to check out www.northernautoparts.com for the rebuild kit they will most likely have the cheapest prices.  

Thanks pontiacman...im assuming you have used this combination before? if you have, do you what kind of compression and horsepower this would give me? thanks very much for the help, especially with the northern site, they have some good deals there. thanks again  

Before you get even more uptight about someone helping you please realize it's not very easy to help you...

When you ask, "please someone help me build my motor," there are literally thousands of topics that could be addressed. I say you get A LOT more specific and make it a little easier for us to address your needs.

A couple of questions to start with...

What kind of vehicle do you have that you have the choice of a Mopar or GM engine? Why the HUGE range of desired horsepower? 300 Hp versus 450 can be the difference in ten or more miles per gallon on the street. I say you narrow down your goals.

For my own input 450 horsepower is by far too much for a daily driver. What kind of street manners do you think you need for a daily driver?  

my question is not someone please build my motor...i asked if anyone has any tips about building low compression motors....i didnt ask for a parts list or for someone to tell me what part i HAVE to buy, but help like that which pontiacman gave was really helpful and i appreciate it...really i dont want help from people like you who jump to conclusions that im getting "uptight"...im behind a computer screen so you really wouldnt know what im doing...i dont appreciate people telling me what im doing...if you think im uptight why would you even want to help me? like i said before, just hints and tips of little things when your building an engine to help lower compression (i.e. use certain thickness for head gaskets)is all i ever wanted to know about....so once again, to anyone who has any tips on building low compression motors out there, id appreciate any help.

thanks  

Just so you know you're asking advice on a topic that is completely arbitrary.

It's impossible to help you with something that has no concrete definition, so I won't! And rather than having you talk down to me, I won't be posting in this topic again. Have fun!  

Great! you basically just contradicted yourself...if the topic is so arbitrary and has no definition (although someone else has already been very helpful about it) then why would you have even posted in the first place at all? you shouldnt have came on this thread talking down to me when you have nothing to say at all...as the saying goes, if you got nothing good to say, dont say it at all....and thank you for wishin me fun, as this is quite entertaining

Back to the original thread...if anyone can lend a hand with any tips or advice on building a low compression motor, please help...i dont want this thread to be ignored now because of this stupid useless shitstorm started by a cocky no it all...im asking for help, which means im short of knowledge, so please share anything you guys no on the topic. thanks  

Problem is you've done no research on your own.  This is perhaps the most popular type of build in the history of hot-rodding...and you're asking for extremely general help on it.  Pump gas??  Simple...keep your compression ratio below 9.6:1 for all iron...less than 10.5:1 for aluminum heads.  Other than that its the same formula as any other engine...get a good set of cylinder heads, decent intake, decent headers, properly sized cam and carb.

This is not a low compression engine.  A low compression engine would be something in the 8:1 compression range (or lower)...generally saved for forced induction applications.  Just about any build you find on the internet is going to be for pump gas (unless otherwise stated).  Hell CC has a build using Vortec heads that resulted in 440 HP.  That one has 10:1 compression...but you could easily drop that to 9.5:1 (though I doubt it needs it).

Read the tech articles on CC, Hot Rod, Chevy Hi-Performance, Popular Hot Rodding, and similar sites...  

well i have done the research but i havent included any of my own knowledge for sake of having someone give me their side of the story...i already knew i would probably need a 9.5:1 compression ratio since i am going to use iron heads, and i have looked over alot of the tech articles here and at mopar muscle on this topic...i was just hoping that maybe some of you out there have similar motors (340 mopar or 350 chev) that you guys run on pump gas on the street and get good mpg's with, and if you do, any tricks or tips on what you have done/do...i guess since this is so hard for alot of people to answer, as I can tell by previous posts, im just going to go with what i already know...the question is very general, i agree, but the responses have all been more than vague...just any little tips and tricks is all i was asking about, but thanks anyways guys.  

Your compression will be around 9.5:1 and should put out 375H.P. with a good dual plane intake like a summit stage 2 or a weiand stleath manifold maybe alittle more. Also I think cc did a article on iron vs aluminum heads they had if I remember right 10.88:1 with no detenation from either. I have went as high as 11:1 CR with iron heads with no detenation on 93 octane it's all about the timing.  

cool man that sounds awesome...if i do end up building my chevy motor im probably gonna go the route you mentioned...seems like a good setup and isnt gonna break the bank either man....thanks alot i really appreciate it  

Your welcome just glad I could help.