Please post details on that motor. You simply dont need 195cc heads on a TBI motor under 5800 rpm.

https://www.thirdgen.org/forums/tbi/...ile-quick.html

1/4 mile quick TBI's.. i see 13's in there... best one ever that i have seen is Fast355's 312 vortec TBI that moves a 5600lb van to 99mph. That is a vortec motor that doesnt have 195cc heads either...i dont have the dyno chart but from what I remember seeing it was done by 6000 rpm
Again i dont see the point in buying new 195 cc heads for a street only driven non 1/4 mile 350" TBI type motor trying to get 20's mpg

 

Do you guys really put MGP at the top of the list when you are planning a build? I understand it's ON the list. I was referring to LSx motors before, big heads, big power, decent mpg.

There is not many wild TBI builds to reference unfortunately, most guys go the truck motor route on TGO or they go carb. I take Fast355's opinion on the matter in high regard, he says; Note he didn't say he ran out of throttle body. Surely he came to this conclusion tuning the ECM.

If that dyno is one I'm thinking of it's cut off at 6300RPM where it was still peaking. Of course you wouldn't put 195cc heads on a street 305 . And his vortecs were ported too, IIRC, so we can assume over 170cc.

I agree you don't need 195cc heads for that RPM, but that doesn't mean it's a bad idea. You could use 160cc heads if you wanted, it would still make power there. Sound logic but poor advice IMO.

There's other good heads out there but I choose these based on the OP's wants. Aluminum, Broad power band, under $1200. They fit the bill perfectly my .

 

Here is a down right nasty TBI thanks Fast355.

https://www.thirdgen.org/forums/tbi/...ack-times.html

Still making crazy power at 6,600 RPM with TBI. There is a lot of good information in that thread check it out.

 

Go back and read the first post of this thread and post #9...why do you want him to build a high rpm race motor? Thats not what this thread is about. Broad powerband with TBI is 0-6000. If it was another intake, go for revs ands 195 heads. I'll leave it at that because I can see we are butting heads and will have to disagree
There must be a reason for this...and its not because people tend to build truck motors

Plus LSx is completely different animal all together than SBC. 95% of sbc builds will never match the power and efficiency of the LSx

2.02 valve 195's from profiler may end up costing 1200+ if you get them with better quality components than what some sell them with for 950 bucks. They will work but I dont think anywhere near as well as a proper spec'd head for that RPM range. If you upgrade from TBI then yes, 195's are there in the future for more power and revs

 

Probably the only TBI build where I've seen high rpm potential..and guess what...mild ported ZZ4 heads which are in the 170-180cc range. You could get similar 6000-6400 rpm performance with a 350 with same setup and not have to turn the rpm of that 312 (6500+). You dont really need the 195's. That 312 moved well since its a 2840lb car with driver. An average street thirdgen is 3400lbs..big difference there, and with a stick..that low end will be suffering

I'd be real curious how that little motor runs with 280XFI cam..I've been in a 350 HSR car with that cam at full weight and its streetable but not quite a broad powerband...needs 3600 stall and revved up. Probably better with 4000. Its definately cammed. I'd go alittle less cam and with good compression it will have a great broad torque curve and hp curve

 

The cross sectional needs between a 305 and 350 are very different. Using a stock 170cc Vortec head that is 1.66 for example on a 305 that would be 5,900 RPM limit and a 350 would be 5,100 limit before the port starts to lock up.

The ported zz4 heads is a great idea for someone who's some what experienced. I honestly can't recommend a noobish type grinding on valuable heads like that though, it's just not realistic. I would port a set up with bigger valves if I found a pair cheap enough, better be damn cheap too since I don't get free hardware or machine work. But grabbing a pair for a "first" port job?

6k is not radical, and it's not "high rpm race motor", my . Fast355 has loads of videos idling, warming up, racing, ect. It sounds rock solid and make 300ftlbs at 2k. That's not bad for that cam, that peak, in that 305.

Orr I don't see people even trying to build a TBI screamer so the only results I do see are successful ones. All the slow ones are built slow and follow suit.

I again agree that the LSx makes is effienct and makes more power then 95% of our SBC's and the feedback in this thread has a good bit to do with it IMO.

 

Yeah, I was recommending a professional to do the port job on the set which can be found for 300 bucks. Just a thought.

I agree, 6k rpm is not high rpm race motor but 6500+ is getting up there for a milder street build goal in mind. My 383 could go to 7K and it was a blast but it was certainly not for everyone. Maybe I am just assuming the OP's goals are alot more mild than what he has in mind. When I see TBI and 210-220-ish deg cams in the first post, I think somewhat conservative build where big heads arent necessary even tho there are good deals out there.

Hoping to see more TBI builders chime in. I'm new to TBI so just browsing and offering my 2 cents worth

 

Agreed, those take some work and larger valves to get them to do anything.
Think the best I got out of a stock valved 113 head was 230ish int/207 exh@.600 lift which really isnt impressive at all. The guy they were for was on an extremely tight budget running a small cam;looking back I wouldnt do it again. Ran strong though enough to scatter a 2k trans within 8 miles though lol.

They really need a bigger valve and some "real work" to make it into something decent the intake port, seats etc arent real great yet people go gaga over them and pay a lot even for a used set.
In the right hands they can make some fair power though.