for streetability like i am at 13.6:1 right now with ths stock heads milled to 50 cc's even at the 54 cc stock it would have been 12.5:1 real high for my liking to even try a mix of pump gas i run straight vp 116 @ $5.50 a gal lots of people are not willing to do this so instead they get heads with bigger cc and reduce it to around 11.1 which you can run 93 all day on

 

I didn't think about a stroker's compression being higher... I see.


So the general idea everyone can agree on is no heads/cam without beefing the bottom end of the motor? I could have sworn it was pretty common to just bolt on heads and cam with no issues.

 

I don't know if I would say it can't be done without working on the bottom end but since we all know that working on these cars is a PITA why not do some bottom end work if you are taking off the heads and putting in a new cam? Well, actually there are a lot of reasons like not wanting to take your motor out!

Of course this could lead to a lot more money obviously and depending on the miles and condition of your stock bottom end it may be OK with stock parts. However, I don't think THESE heads are designed to be used on a stock bottom end. I think there are plenty of guys porting stock heads with the stock bottom end.

 

I thought I read that they flowed 212

 

The Trickflow Combustion chambers are 62cc and it's not hard to angle mill .030 off and get them down to 58cc that is what I had done to my new heads. I bought them new from a guy off the board bare for $700 shipped and sent them to Lloyd E to get ported. I already had 2.05 intake valves, 1.625ex valves and titanium retainers so for $1,500 complete including new valve springs, machine work and porting I have some killer heads that flow 300cfm@600lift. These heads are really nice and just got finished up on my 355" LT1. I should have some new times in the next week or so then I plan on doing some dynoing. It would be another $300 for Ferra valves and Titanium retainers still only $1,800 for some really nice heads. Later Clint

 

I think they are good heads but definitely get them ported if you wanna get the most potential out of them. For that much money you could port LT1 stock castings that would outflow the Trick Flow heads in their original condition.

 

I agree. I would port the stockers, or go with something besides the trickflows. They really drop the compression ratio.

 

http://chevyhiperformance.com/techarticles/41598/

Great database for flow numbers. Looks like LT4 heads are just as good as trick flows, and those are a factory direct item. I was right on the stock LT1 heads, they are more in the 212 range, not the 230 range like someone else suggested.

 

When I started researching my 383ci. build, I wanted to sell my
LT4 heads and get some TF's and use a flat top piston.

After much debate with my LTx friends, I decided to get a dished piston,
keep the LT4 heads and have Lloyd E. work his magic on them.

If I already had a set of TF's I would have kept them and sent them to
Lloyd, but LT4's are a fine head that can stack up against the TF's.

LT1's flow about 210'ish
LT4's flow about 240'ish
...and I don't know what the TF's are doing.

I may get some TF heads and a blower somewhere down the line though...
I love having that option!

 

well my cousin has a flow bench and my castings were close to 230 stock

 

On a flat top piston stroker they are a great place to start from. Porting them is a good idea as well, but I wouldn't put them on a 350-355 motor since you just cant get the compression out of them that you need.

Here is a example of what they can flow:

Flow Numbers
Lift--Intake--Exhaust
.200--138.9---106.7
.300--204.4---153.2
.400--249.0---185.7
.450--268.5
.500--289.2---210.9
.550--297.3
.600--307.4---222.0
.650--307.7---
.700--308.0---228.8
.750--308.0
.800--308.2---234.8

I've seen a lot of TFS castings ported and most times they can get to 290-300cfm.

Bret

 

Well Brett I understand your point about compression but what kind of compression do you think my 355" LT1 has now since I put the TF's on? I anglemilled .030 off them, zero decked block, Flattop Lunati pistons and running a Felpro .039 thick headgasket. I fiqured at least 10.5-10.8.1. I had a problem with my fuel rail this weekend so I didn't get to go run the car yet. Later Clint

 

why 30 thou they did not cc them to make sure they are equal ????

 

~10.8:1 is what I calculate. Assuming 7cc's ?? for the flat tops.

-Mindgame

 

Clint, you are very close. Everything I calculate show that if you have zero deck, flat top pistons (7cc valve reliefs) on a 4.03 bore, wtih a 4.1 gasket bore (average felpro gasket bore), and a .039 compressed gasket thinkness , on a stock stroke is:

• 10.905156625938348:1 Compreesion with 58cc heads (what you said the TF's would be after anglemilled)
• 10.157011211931703:1 Compreesion with 64cc heads
• 11.475749186530954:1 Compreesion with 54cc heads (if this was done with unmilled stockers)

So, if your heads are anywhere below 61 cc's you will be at least 10.5:1 or so.
I can give you a closer number if we had the exact size of the heads combustion chamber volume, and valve reliefs...