3400 build up

[rx191]

i'm looking into building a very hi po 3400 and wanted some intoo my specs,

3400 block stock bore
3.4 dohc pistons
stock rods shot peened polished with arp bolts
crank knife eged and the whole lower end balenced
3500 heads gasket matched and cleaned up
3400 upper manifold poted with twin 58 mm throttle body on it flows 1065cfm
roller cam with roads chevy lifters
cam specs:

lobe center 114
intake centerline 112
intake duration 282
exhaust duration 286
intake lift 530
exhaust lift 550

compression should be about 11.50, custom headers with 40" primarys and 1 5/8" tube, crane rockers and custom pushrods. looking for about 350+ hp
engine will be spun about 8200 rpm max! the engine will also be megasquirted what do you guys think.

[bszopi]

Twin 58mm TB is WAAAAAAY overkill.

Is this RWD? IIRC, you have a FWD car, so the 40" primaries on the headers is going to be near impossible.

No way it will spin to 8200rpm. Modded DOHCs don't even spin that high. There is no way you will get one of these pushrod engines to do it.

[AaronGTR]

Yeah, no 8200 rpm. Especially with stock rods, I don't care what you've done to them or what rod bolts you use. You'd have to destroke the motor to get much higher than 7000 rpm, and then you'll run into valve train stability issues. You'd need something like the shaft mount rocker systems they have for the LSx engines, but since we have splayed valve heads thats impossible. I think you need to be more realistic about your build. What about those lifters you mentioned too... do you even know if they'll fit a 3400 block? I've never heard of anyone finding any lifter alternatives for it.

[rx191]

boy i'm starting to think this site is full of pepole who don't know much of anything, i know of at least 3 people who have built very high performance race motors that are spinning them 8000+ RPM, the heads will support this and more if preped right, ask around on here i remmber talkingto a few guys thatare spinning there motors to 7500 rpm, the rods i'm not sure if they will be good to 8000rpm but i guess we will find out. the motor will not be going into a FWD car it's going into a custom built race car that is RWD, and by the way bszopi the throttle body is only 8% over what the enigne will use for peak power at 7000 rpm, it is not overkill for a full race motor. you need to go and learn a little more about something with a very high VE% i have built many engine that have made upwards of 2 hp per liter and i know what it will take to get it there.

[IsaacHayes]

Yeah, what everyone else has said. If you want to rev, go with a 2.8 crank, destroking the motor to 3.1L. I'm not sure if destroking will let you run higher compression on less octane (I read somewhere years ago that it can sometimes), but it would help you rev more.

I'd keep the 3500 UIM though, and gasket match everything. The 3500 is a nice design which once port matched will gain you power over a 3400 anyday. And it accepts a 65mm TB stock (no porting for that).

[bszopi]

Then maybe you should say all that in your first post. There is a difference between a hi-po 3400 in a street car and a race prep 3400. And if you have already built so many hi end engines and you know what it takes to get there, why are you asking a bunch of people who "don't know much of anything"?

[john_V63400]

I agree with BsZopi. You should of said race prep racing.
I think you could come close.
But forget about using those stock rods.
U got some good ideas though. Good Luck

[SappySE107]

Sorry.

How much experience do you have with 60V6 engines? How many of those high RPM engines were 60V6s? How many used modified stock forged rods achieve that? How many used modified hydraulic roller lifters? How aggressive is the ramp up rate on that cam (need more specs). Why are you using a 3400 upper intake manifold? Why only 1 5/8 with custom headers pushing 350 hp? Why 40" long for 8000 RPM operation? What are you doing to lower the compression using 3500 heads and 3.4 DOHC pistons (something needs to be modified quite a bit).

You sound pretty arrogant to be questioning our knowledge of what you did and did not mention in your first post. I look forward to your answers.

[AaronGTR]

I really doubt you'll be able to run adjustable rockers on those heads at 8200rpm with any kind of stability. The stock guide plates most use for those aren't that strong either so you'd at least need custom guide plates... also seeing as how they won't fit on the 3500 heads unless you don't mind grinding down the tops of a couple of intake runners. So thicker custom guides would be the way to go. Of course if you're talking about a racing engine that really changes things doesn't it? And you should know all this so why ask us in the first place?

[rx191]

i do not have very much experince with high rpm 60 v6 motors i have only built one and it was a drag motor that was rebuilt after every race and only ran about 3 min at a time, it was spun to 9000rpm but only for a sec. it was a 3100 with a custom twin turbo set up. anyway i'm figureing on makeing peak power at about 7200-7500 rpm with redline (limiter) set at 8000rpm i don't know if the stock rods are good to that or not even preped thats why i was looking for peoples opinions, i haven't decidedon a ramp rate for the cam yet but it will problay be pretty agressive, i also have looked into lifters, i can bore the lifter galleys a little bit and fit sbc rollers in the block i planed on useing roads lifters. the reason i'm using the 3400 upper is because 1 i have a spare, 2 it's an open chamber so it will work well with the throttle body i have, i don't know if it will have enough volume or not but i can modify it or build a custom intake if it doesn't work. and you where right about he compression ratio my math was a little off, so i may run a 3.4 piston to get near what i want, the 40" long primary is just what the cars frame desighn calls for but i can shorten or lenghten them if needed, (i haven't done any figures on it yet) and i aslo didn't mention it will be a race motor because i figured anyone witha little sence would have looked at the basic cam spec and compression and figured it isn't going to be driven much on the street. i haven't looked into the vavletrain yet but i do plan on running a custom guide plate with custom rockers, i ahve been thinking about destrocking the thing but haven't really lookedinto it yet to see what my options are, i really don't want to mess with a custom rod if idon't have to, it's a pain in the but to get it done right around here, i figured a stock well preped rod would be good to 7500 rpm and 8000rpm on miss shift.

[SappySE107]

What else was done to the 3100 to run 9000 RPM. How much did that cost? The rods will handle an 8000 burst from a missed shift, but thats about all I have heard on them. You should go with an aftermarket rod and piston though for anything like what you want.

Your compression is kinda low for me to consider it an NA race engine.

[AaronGTR]

I agree ^ , aftermarket rods and pistons will be needed to keep it from coming apart at those rpm. 11.5:1 compression is pretty high for a street engine, but for an NA race engine you should be higher and running race gas, maybe methanol too.

The cam specs wouldn't give us any clue that you were building a race motor. They aren't all THAT extreme. People around here are running cams on the street with similar lifts and some pretty long durations. The only real clue to the motors purpose is the rpm you want to run.

[SappySE107]

Yup, and that centerline doesn't scream high RPM either.

[rx191]

what you guys recommend for a good cam, those are specs i came up with using a dyno simulator i have, the engine seemed to make good power every where with those specs, so any thing you guys recommend i will look into, i was goign torun a custom piston based on the 3400 DOHC piston specs but i may add a inverted dome into them to get teh compression where i want it, i guess i could mod the rods but if i do i'm playing with the idea of doing a 3400 with a 2.8 eagle crank, with a 6.00 rod

[SappySE107]

I want to see this drag motor you talk about. Im sorry, but after you tell us how we don't know shit, and now you are asking us questions...I dunno. You made a deal out of 2hp per liter (so less than 10 hp for a 3.4 liter V6). You haven't answered my question about the twin turbo 3100 drag car that turns 9000 RPM. You rebuilt it after every race, so how quick was it? What kind of parts were you putting in it after every race? Do they give you time to tear it down to replace parts like that or did you keep a stack of them in the trailer to swap out after every race?

What length rods did the race motor use? Got pics? Id love to see something that bad ass.