I asked this in the LT1 section and had no replies so I'm gonna try this here. What would be the difference between getting a set of AFR LT4 195's ported and polished and a set of AFR LT4 210's basic package ? Would there be that much of a performance difference ? How much of a technical difference would there be ? (besides the obvious diofference in runner size) Would the flow numbers be so much different that one cam wouldn't work with both ?

Thanks,

 

They tell me that up to (I think) the 220CC runner they are the same casting,just machined different sizes.
There is confusion when people say I'm running a 195CC head,when in reality the heads have been ported and are actually a 220CC.They just BOUGHT a 195 and had them fixed and try to lead ya to believe they are doing miracles with a small runner head,ya know the I am doing this with the smallest head they make syndrome. Doing more with less and they ain't,they just want you to believe they are doing big miracles and the best on earth!!!!!!
Don't exactly know off hand what the flow number difference is but a 30CFM difference is about 60FWHP and thats BIG.
Don't let ANYBODY tell ya that big ports are lazy,just ain't so. Having said that don't go and put a 410CFM head on a 355 and expect it to peak power at 6,000 ya will need to take it to 9,000. So ya need a head to fit your app and RPM's but not small and with the right cross section area.A 383 will need 300CFM++ to start make the HP it is capable of.Our 383 has 247CC runners and flow 330ish with a2.080 valve and is capable of supporting 680-700FWHP if everything else is correct.
Ya also need an intake that don't take 10+% away from the head flow when attached.

 

Well the reason I ask is because sometime in the near future I will be building up a 383/396 (haven't decided which one yet). I do want it to be semi-streetable as it will only see the track 6-7 times a year and I really don't want to have to spin it over 7000 rpm. My train of thought was "why pay $1800 for a set of heads (195's) and then put another $1000 into head work if I can buy a set of 210's with some minor clean up and end up with the same thing. Does that make sense ? Thanks for the reply.

 

Very much so.just remember 300CFM and the larger th head the smaller the cam has to be to make the same HP.If ya are using the stock manifold take 10=12% off of the head flow and a 300+CFM head is plenty street able.

 

So what all would I have to do to a stock LT4 intake to make it keep up with the 210 heads ? (Besides porting for the 58mm throttle body) Would just port matching be enough or would the intake have to be cut apart to have more work done ? Also, If what I'm looking for is 300+ cfm would it just be better to get the 220's instead of the 210's? After all, they are the same price. Just remember this is going to be mainly a (semi) street car.

Thanks again.

 

Always go with the best head ya can afford and build the engine around them.
There is nothing ya can do to the stock intake that will cure it's ill's.Ya can help it but if ya really want to make HP ya need another type and a LT-4 won't do it.This is why I say big heads.If ya get a set that flow 330 then the piston might see 300CFM.(10% is a rule of thumb) and the stock intake takes away more than that. This is one of the main reasons most all engines on the board top at about 400RWHP.

 

Don't get the 190/195 heads. We've flowed a couple sets at Thunder and got 230 - 240 cfm peak. 210's and up, however, do within 5 cfm of advertised. My 210 Race Ready's flowed 280i/218e peak.

1racerdude is right, big ports don't make a motor lazy down low unless you get ridiculous with it. Too big a port may lose 10 ftlb peak down low.

The 220's offset the intake pushrod. Some say that this has caused valvetrain geometry problems (a la TFS Twisted Wedge). I don't know if it's worth this risk for the 5 extra cfm they advertise.

I've seen the LT4 intake chop 30 cfm off a good head's flow numbers. That can be helped quite a bit by raising the runner roof until it breaks through by the injector, then welding up the hole.

Mike

 

Keep up the good responses. I may buy me a set of 210's to replace my cracked LT1's. Would you guys think that a new AFR 210cc head flows more than my old max ported LT1 castings with 2.065/1.600 valves. These really worked well about 450-475FWHP but I would like to buy AFR's just don't have the cash to buy them then port work extra $1k. LMK combo below. Later Clint

 

If ya have to go offset rockers I would get the 227's.I have used them with stud RR's just like a TFS on a Ford and they worked when ya get the guide plates right.

 

I would rather stay with the conventional rockers and the 210's if they won't sacrafice making 500fwhp N/A and about 750 on gas? LMK your opinions. My old combo with 175 and 200HPNX was a beast 10.17@134mph with a 1.52 60' spinning, 3.42's and 28" tall drag radials. I am going to try some 3.70's in my 8.8" Ford and leaving with 125-150HP off the T-brake and another 100HP once it leaves. LMK Clint

 

One of my friends has some mildly cleaned up AFR 210 Race Ready's that still flowed 280/220 on a 408 SBC with a Victor Jr, Holley 750, and 257/269 solid roller. He made 637 fwhp and 550 ftlb torque, so I think they can cover 500 fwhp.

 

Remember the intake,the number's are good on those heads, but the difference in intakes will take 10-15% off the head numbers.@15% that's 238,don't see 500FWHP there(470 maybe,with a BIG old stupid cam). Ya need to get in the 320-330 range to use a LT-1/4 style intake and can make 600+FWHP if the intake flows within 10-15% of the head flow when bolted together.It may be more.

 

Yeah I could see swapping to a VictorE EFI setup on top of those AFR's if it will make 600FWHP or so. Then spraying 200HP would be a 800+HP LT1. That will move a 3,400lb T/A pretty good into the low 9's. Later Clint

 

If 10% reduction in flow results in 10% reduction in hp, then 637 fwhp - 10% = 573 fwhp with BIG old stupid cam that makes power.

 

Did he say his engine was a carbed 408 making 637HP,and would those heads make that HP on his engine??? Remains to be seen(don't think so) IF a street engine on pump gas with a LT-1/4 intake would do that with a cam that is decent for most people.Big and stupid cam is a mech roller in the 260's@50 on a 108+4 and 700+ lift.