R23HTC

Anyone using these heads? http://store.summitracing.com/defaul...Cylinder+Heads

I've lost compression in my #2 cylinder and after doing a compression test believe it's in the head. Probably burnt one of my stock valves. I didn't do much on the upper end when I did the rebuild because it wasn't in the budget and I was planning on doing that later. Well now it appears later just got to be sooner. If I could get away with just swapping heads for now, that would probably be the best. Opinions welcome. All my mods are in on my link in my sig.

FD2BLK

Do a leak down check first and if you need head you may need to look to another set other then TF.

The problem with the TF heads is they have a 64cc combustion chamber and you already have your bottom nend built to work with 54cc heads. If you need them quick (AFR back ordered 10-12 weeks) then you could get a used set of stock cast LT1 heads for $200-300 and get them ported (There is a great GP in the FS section). Another option is a set of LT4 heads (but they will not flow as well as a good set of worked LT1's). If you want a set of LT1 AFR heads you can check with TPIS, I canceled my order last week and they may have a set in stock ready to go.

Cherry6speed

I believe Lt-1 heads ported stage 2 can perform at least as good as those and Stage 3 porting will outperform them. Do you have any flow #'s ? I believe you will come out cheaper in the long run building your heads. Now that's not to say a nice set of AFR 195's and a LT-4 intake wouldn't change my mind That would be a sweet set-up for your 383

kwik_ta

I wouldn't put Trick Flows on a 383. The combustion chamber is smaller and the set up limits you to a max lift of .550 (maybe .60) I don't remember which. TF's are great on a stock motor, but don't seem to perform as nicely on a modded motor or larger displacement motors. Getting the stock heads reworked seems to be a good option. I've heard several great things about AFR heads, but don't know a thing about them. If you go that route, please post flow and dyno ##'s. I'd be interested in seeing those results.

FD2BLK

[QUOTE=kwik_ta]I wouldn't put Trick Flows on a 383. The combustion chamber is smaller and the set up limits you to a max lift of .550 (maybe .60) I don't remember which. [QUOTE]


On a LT1 the Trick Flows have larger chambers 64cc -vs- 54cc (Stock)

R23HTC

[QUOTE=FD2BLK][QUOTE=kwik_ta]I wouldn't put Trick Flows on a 383. The combustion chamber is smaller and the set up limits you to a max lift of .550 (maybe .60) I don't remember which. So that's an advantage or dis-advantage? I don't know much about this at all which is why I'm trying to find out. I had intended on replacing the cam with a custom grind to match a set of heads, but since this happened sooner than I had planned, will my hot cam work with these heads?

I really hate to pull the heads and not install all new parts this time.

FD2BLK

In your case it is a disadvantage (Lower compresion)
You can check with TPIS, they may have a set of AFR LT1 heads in stock ( I cancled an order last week) if you realy want new heads but a set of used LT1's and a good porting would be a great solution as well.

redfast

The only disadvantage it would make is a lower comp. ratio. About a point. I have trick-flows with a built bottom end, tpiszz9x cam mini-ram and the heads are great. You can get the cnc'ed one's for summit like I did and port them your self and there great. I did this b/c i was going to use the AFR's but the flow#'s are close and since i have mine ported they flow pretty close. Doing this I saved 8 hundred bucks and did'nt have to wait months for AFR's.

R23HTC

Well if I spend as much as AFR wants I'll probably get a set of GTP's. I'm still trying to figure out what I want to do.

FD2BLK

That is a big change in comp. The whole atvantage of the LT1 is the fact we have reverse cooling and can run the high comp #s without detonation. The HP would drop quite a bit with that big of a change in comp. If the bottom end was built around the heads then the piston selection can take care of the problem but if you already have a bottom end, like this case, designed to work with 54cc chambers then I would stay with the correct combustion chamber size. As far as GTP goes they are great but don't they just port heads? Stge 3 $2899

aklim

When I first bought the heads, I asked their tech sopport if my RR will clear the head and they didn't know. Asked them whether the cam had too high a lift and they didn't know either. Finally ended up ordering perimeter bolt heads with their improved springs and they didn't have them made up so I had to buy their springs and have them installed myself. Had to clay the engine to find out that there was tons of room. Of course, if I had known that there was no room, I would not have had the motor torn apart at a facility 150 miles away. Instead I had to chance it.

Less than 2 weeks after I had it installed, they sent me a set of guideplates because the ones on the head were not up to spec. Here we go again into the VC area.

Just less than 3 months after the job, I found out that my motor was junk. Call that inexperience. I should have done a compression check. Well, out came that motor and I had LPE clean the heads and check them and at the time, they were fine.

Well, 3 years later, I forget what I was trying to fix. Either an oil leak or some rattling coming from under the VC. Found out that the driver side was fine but the passenger side had "C"s worn out into the guideplates. Took out a guideplate and while I was looking around, I found a broken spring. Replaced it and all the worn guideplates.

6 months later I took the intake manifold out to fix another oil leak. Decided to take the heads off to see if there was any damage since the compression came out around 165 to 180 psi. Found out that the 165 psi one was the #4. When I removed the head I found that I could see the piston ring because a chunk had been broken off by the valve and bounced around. Cylinder was scarred beyond repair and piston was broken. Took the motor out and bought new heads. Traded the TFS ones in towards the R&R. They took the heads apart to inspect them. The driver side one was good. The pass side was so loose that the valves rattled in the guides once the springs were removed.

I'm fairly certain that the resistance between the pushrod and the guideplate and the wobbling of the valves combined caused some sort of problem with the spring and it broke. Since there were 2 springs and 1 broke, it could still close but at higher RPM, it would float and bounced off the piston.

G-Racer

Why not rebuild your cylinder heads ? A good valve job and some professional port work and you will be very satisfied. Check out my site
www.steadfastperformance.com

kwik_ta

All good info!!! It looks like the general consensus is that Twisted Wedge heads are not a good investment. Please let me know what you decide. This has become a rather interesting topic.

R23HTC

Well from reading these posts, I've decided not to get the Trick Flow heads. My problem is, I'd like to get it fixed inexpensively for now, yet I don't want to be pulling my heads and replacing parts if it's not going to be what I had planned on doing in the furture. The plan was to go with what I had till I could get everything else. Now I'm stuck in the middle trying to decide what to do. Since moving to Ohio, we've realized I'm probably going to need a winter car anyway, so I'm probably just going to let the Vette sit till I can get it done right.

What I was considering for the furture was a port and polished intake, headers, GTP stage 2 heads, ASM 58mm TB, and a custom grind cam to match all that. That would also require changing my programming. That would basically finish off the motor to the way I want it.

Now I'm stuck between a rock and a hard place trying to decide to "throw" it back together, or wait and do what I want. Unless I can do it myself for around $1000 and use NEW parts, I'm leaning towards waiting. I don't think I could piece the above and have it run properly.

If I were just to put the GTP stage 2 heads on and run the hot cam, 52mm TB, and stock exhaust manifolds, I'm not sure I wouldn't be restricting it to much? Thoughts? If it's possible, then I may just start off with that.

LT4POWR

Ported TFS heads are a very good choice for a 383. If I had a 383 and needed heads they would be at the top of my list. The only real issue with them is with milling you're only lookin at a combustion chamber volume in the high 50s. Getting your intake port matched would also be a good idea. GTP heads are way overpriced. If you really wanna get some ported stock heads, let me know. I can point you in the right direction. Here is some info I got from a very good LT1 engine builder about the TFS heads...

I have seen 300cfm on a 95-97% max port job on the Trick Flows. High 220's on the exhaust. That's with the right cross section and volume for a 383, never seen a LT1 casting get to the right cross section for a 383 and be worth a **** on them. Most I have seen on a LT1 casting is 275cfm at .500 and up, then again claimed numbers of 280+ never make high 260's on the bench here so it's all relative. Really cfm doesn't mean **** since the min cross section on a LT1 head is so little for any motor over a 355, if you want to make more than Tq on a 383 you have to get a casting that will flow enough and not choke off the system at higher RPM.

I know they can flow up to 300cfm Intake / 225cfm exhaust on the stock valve seats so yeah they are a good place to start. On top of that they have a much better coolant passage design than the AFR's which means more compression or more timing can be used, so therefore more power.
specs...

Trickflow Specialties LT1 23* Cylinder Head

Specifications
Part Numbers: Assembled: 30400010 Bare: 3042B010

Material: A356-T6 Aluminum.

Intake Port Size: 195cc 2.07”x 1.26” Port Opening. (Stock LT1 port opening)

Exhaust Port Size: 75cc, 1.35” Tall x 1.50” Wide.

Combustion Chambers: 62cc.

Valve Sizes: 2.02” Intake, 4.690” OAL, 11/32” Diameter, .250” Tip TFS #51400211
1.60” Exhaust, 4.980” OAL, 11/32” Diameter, .250” Tip TFS #51400212

Valve Guide Material: Manganese Bronze, .500” OD.

Valvetrain Componentry
Valve Locks: 7* Steel, + .050” Installed Height. TFS #51400444

Valvespring Retainers: 7* Steel, 1.460” Diameter. TFS #51400423

Valvesprings: 1.460” Diameter, Dual Spring. TFS #31400414
125lbs Seat PSI @ 1.780” Installed Height.
375lbs Open PSI @ 1.180” Compressed Height.
420 lbs / inch Spring Rate.
.600” Maximum lift.

Valve Seals: Positive Clamp Viton Rubber. TFS # 51400454

Rocker arm Studs: ARP 3/8” diameter. TFS # 51400613

Pushrod Guide plates: For use with 5/16” diameter hardened pushrods. TFS #30400623-8

Flow Data
Intake Exhaust
.100” 50 57
.200” 135 98
.300” 191 136
.400” 229 162
.500” 253 176
.600” 254 189

Exhaust flow testing was done WITHOUT the use of a pipe.
2.02”/1.60” Valve sizes. All testing was done on an AS CAST head.
Flow Testing was done at 28” H2O.

lawcorvette

I have TFS twisted wedge heads on my 406. I got them a while ago when they first came out and they have been ported to a 1206 gasket. My motor has not been started yet as I am still building the car. It is a weekend project- whole drivetrain has been replaced, but these are my observations.

1) The different valve angles of the twisted wedge heads cause headaches.... period. If the valve train geometry is off the valves will run along the guideplate (sideloading) and wear them prematurely. For this reason you have to use an adjustable pushrod checker as trick flow suggests to determine pushrod length.

2) larger spring diameters can cause a problem with roller rockers. I had to go to a stock diameter spring in conjunction with 1.6 crane gold roller rockers to avoid any crashing with the roller rocker fulcrum and the spring.

3) TFS will only recommend crane gold roller rockers... It is something about the dimension from the bearing to the fulcrum.

4) TFS springs as originally provided are low quality- I upgraded to cranes that would support my zz9 camshaft.


I believe the TFS twisted wedge heads may be a good choice if ported and set up correctly and I hope they perform well on my engine as they have caused difficulty in the planning and execution of my engine build.

R23HTC

Thanks for your reply. I've totally ruled them out at this point. I hope you get your problems worked out.

ASRoff

The LT1 heads from trick flow are not a twisted wedge design.

Phil from A.I. has done some testing on these heads. He says that out of the box they flow slightly better than LT-4 heads. When he tryed to port them he ran into thin walls. He called Trick flow and asked them about it they were ral interested in looking at the heads he had because they beleve that the core shifted. Phil stated that if that were the case he would have no problem getting 300 cfm out of them.

If you want to read more about them go to CamaroZ28.com and do a search for "Trick Flow heads" on the LT-1 Tech forum.

I plan to run these heads because they are a hell of alot cheaper than AFR's