Cylinder head prep Level 1
- Thread starter Jeffyoung
- Start date
JessePrather
Well-known member
Full prep is full porting on the head. Whatever you want to do. Valve size is limited by the spec line but besides that it's wide open.
In the older full prep cars that included compression, intake manifold, etc.
Nearly killed off prod in the 90's with guys building time bombs. My dad always had 2 engines over 15:1 compression in his MGA and often the engine got swapped at the runoffs for the 1 race engine. At the minimum we'd pull the head and lap the valves and change the head gasket. I don't miss those days...
In the older full prep cars that included compression, intake manifold, etc.
Nearly killed off prod in the 90's with guys building time bombs. My dad always had 2 engines over 15:1 compression in his MGA and often the engine got swapped at the runoffs for the 1 race engine. At the minimum we'd pull the head and lap the valves and change the head gasket. I don't miss those days...
hoffman900
Well-known member
What Jesse said, with the caveat you can’t add material.
Fun fact, in the 1960s, some of the factory teams had access to raw castings to get around that rule. Something like a TR4 head has too big of intake ports (at the flange) from the factory for their power level back then. Alfa’s are similar as well.
Fun fact, in the 1960s, some of the factory teams had access to raw castings to get around that rule. Something like a TR4 head has too big of intake ports (at the flange) from the factory for their power level back then. Alfa’s are similar as well.
Thanks guys, helpful.
So, advice/recommendation.
I know there is always work to be done to gain power, but I'm very close to the end of the development curve in my opinion. How do I know? Changes are producing no results. I've done 3 custom cam designs, 2 custom exhausts (the last from Mr. Ellston, thanks again Bob), two Rover V8 engine builds prep a set of heads, etc. Nothing is producing any more power at this point. 235 wheel (one plot is at 242 but and a few lower than 235, but 235 is repeatable enough to conclude that's where I am).
Torque curve is flat but not outrageously high --210/220 peak, but flat curve.
I/we/people with a lot of Rover V8 racing experience like John Eales all believe we are at the max of what the heads can support.
Without seeking provoke a debate, a race weight of 2500 lbs before the transmission (necessary as the stock transmission can't handle EP power) and brake (same) modifiers), puts me down quite a bit hp/weight to the BMWs (Ive seen a dyno plot at 268 whp, even if it is 10 less it's still a significant advantage), RX7s (225 whp and something like 2300 lbs), 240z (something like that as well).
So, after 4 years of development (which I admit was more like 2-3 years of "normal time" given Covid), it's time for (in my opinion) a final adjustment to the car. I see two paths forward:
1. Drop the weight to 2350 or so; OR
2. Ask for Full Prep cylinder heads to cure the power deficienncy.
With EP becoming something of a hp war class, I lean towards 2 as 1 doesn't help with hp/drag ratios which are increasingly important.
Thoughts?
So, advice/recommendation.
I know there is always work to be done to gain power, but I'm very close to the end of the development curve in my opinion. How do I know? Changes are producing no results. I've done 3 custom cam designs, 2 custom exhausts (the last from Mr. Ellston, thanks again Bob), two Rover V8 engine builds prep a set of heads, etc. Nothing is producing any more power at this point. 235 wheel (one plot is at 242 but and a few lower than 235, but 235 is repeatable enough to conclude that's where I am).
Torque curve is flat but not outrageously high --210/220 peak, but flat curve.
I/we/people with a lot of Rover V8 racing experience like John Eales all believe we are at the max of what the heads can support.
Without seeking provoke a debate, a race weight of 2500 lbs before the transmission (necessary as the stock transmission can't handle EP power) and brake (same) modifiers), puts me down quite a bit hp/weight to the BMWs (Ive seen a dyno plot at 268 whp, even if it is 10 less it's still a significant advantage), RX7s (225 whp and something like 2300 lbs), 240z (something like that as well).
So, after 4 years of development (which I admit was more like 2-3 years of "normal time" given Covid), it's time for (in my opinion) a final adjustment to the car. I see two paths forward:
1. Drop the weight to 2350 or so; OR
2. Ask for Full Prep cylinder heads to cure the power deficienncy.
With EP becoming something of a hp war class, I lean towards 2 as 1 doesn't help with hp/drag ratios which are increasingly important.
Thoughts?
JessePrather
Well-known member
I'll answer this with an opinion but one that I feel will be the answer from the CRB to your request.
You need to drive this car more. There isn't enough data out there to know what the car can and can't do. I totally understand you've spent a LOT of money on this project however you've been asking for things every year and have continued to get an allowance every year which I think has definitely been warrented. I think you need to focus on getting the car out more so they can see more data on what this car is doing in your hands. Just an honest opinion.
I agree that the car may need some weight off as well.
I don't think you'll get a prep level 1 allowance for the head. The committee has been against any prep level 1 anything for 20 years now.
You need to drive this car more. There isn't enough data out there to know what the car can and can't do. I totally understand you've spent a LOT of money on this project however you've been asking for things every year and have continued to get an allowance every year which I think has definitely been warrented. I think you need to focus on getting the car out more so they can see more data on what this car is doing in your hands. Just an honest opinion.
I agree that the car may need some weight off as well.
I don't think you'll get a prep level 1 allowance for the head. The committee has been against any prep level 1 anything for 20 years now.
Protech Racing
Well-known member
I built a few of these TR8 style cars. They made about 220WHP with the offy intake, crane fire ball cam , and Holley 390 carb . A few more with the holley 650 . They were all done at 6200. Stock with FI was about 155. Carbed was about 140.
The exhaust ports were a large hinder .
The exhaust ports were a large hinder .
Protech Racing":1tryd2rk said:
That's all certainly the conventional wisdom on these cars (well, stock HP ratings were 133 carb, 138 -- sometimes erroneously quoted as 148 -- FI).
Here's what we have learned over 20 years of racing this motor:
1. It will rev. It needs the valvetrain support (rocker shaft supports, billet shafts, etc.) allowed by the rules, but 7000 is not a problem.
2. It will make power above 6200. My peak is around 6600-6700 and it doesn't really start to tail off until close to 7000. This is a stock FI setup (manifold, plenum, throttle body) with the open cam (lift limits) and exhaust, and IT porting on the head.
3. I make 235 whp regularly. Sometimes a few less, one time 242 whp. No one in the Rover V8 world thought this possible. How did we get there? We maximized everything. Three custom cam grinds. Careful legal head work. Good ring package. And most importantly, exhaust. Most Rover V8 people go way to big on the primaries on the 3.5. After using Pipemax to get close, I took it to Calvin Ellston in Charlotte and got him to custom design one. His approach to scavenging and flow really is the main difference I think. The heads are the restriction and this is one of the few ways to really help it.
Protech Racing
Well-known member
Sorry to see you get wrecked.
Can you explain why the ride height is so high?
The car is really well done otherwise.
Thanks
Can you explain why the ride height is so high?
The car is really well done otherwise.
Thanks
Aaron Johnson
Well-known member
I’d kill for 220ftlbs and your weight!
Try the 2686 club and a lot less
Try the 2686 club and a lot less
You want my live rear axle and front struts and shit stock transmission that can't handle 200 whp and shit stock brakes that were dangerous on the ITS car? lol......
So after several months of thought and some basic parts collection, I have decided to build/rebuild the EP Starship Turd8. Build back better. While the original build was close to balls out, we definitely learned some things that can be done better, and will do them this time.
Car is still too heavy at the power it makes v. the Z3 and a few others, but it is close, so hopefully I get it on track late this year and then spend a year racing a LOT. When I was fastest -- winning races and regional championships in a competitive class -- in ITS was when I was racing the most. Hope to see everyone at RA in 2025.
So after several months of thought and some basic parts collection, I have decided to build/rebuild the EP Starship Turd8. Build back better. While the original build was close to balls out, we definitely learned some things that can be done better, and will do them this time.
Car is still too heavy at the power it makes v. the Z3 and a few others, but it is close, so hopefully I get it on track late this year and then spend a year racing a LOT. When I was fastest -- winning races and regional championships in a competitive class -- in ITS was when I was racing the most. Hope to see everyone at RA in 2025.
Just kind of buggered things up with the ride height. On V2, that will be addressed. P.S. I didn't get wrecked, I wrecked. Ugh. Totally my fault. Apologies again to Greg and David.