It wont be long now, I picked up his heads and he is here to pick them up now. He looks pretty happy. The heads are worth more than he paid for the whole engine. Here is a picture, can you guess the size of the valves? They are ported and polished on top of that.

While everyone will OOOHHH and AAAHHH over these heads, I think he is in for a very rude awakening. He wasted his money.

The intake to exhaust ratio will be even worse than it is from the factory, he has shrouded the intake valve a whole bunch, He won't be able to run any kind of camshaft without having to notch the pistons and thus losing compression, He wil be lucky if that intake seat doesn't land on the piston soon, and those puny ass springs will not be able to keep the valves out of float.

Hate to piss on his cheerios but he should have planned a little better. Bigger is not always better.

brutal man! how long till he over rev's this one? jk jay! is it gonna be done by the AX? you promised jay!

Well, ya know, its funny you say that about these heads, he bought the engine from RedBeard and it came with the large valves already installed and the engine was built as a race motor and from what I hear ran very well. I took the heads in for a valve job and to replace one valve that was chewed up on the end from not running valve caps. As for the puny ass springs as you so eloquently put it, what you dont see in the picture is that they are dual springs. I know its hard to see but when they are right in front of you, it shows. I dont think he will have any problems with these heads. I took them in to have them all checked out so he wouldnt have any problems. Rimco has been doing these for many years. So piss away, I think he is having corn flakes anyway.

i have to agree on that part, he should have opted for bigger exhaust valves instead,
to help the engine breath ...

Andy

The dimensions are 48X38, what are the factory sizes?

Stock 2.0 liter is 42 x 36.

Don't listen to these guys, the heads are going to be just fine, plus they are nice and shiny.

I assume he didn't use the 1.8.

Did he spring for a new clutch?

Did he buy a book on sync'ing carbs?

Inquiring minds want to know............................

They will be fine. Could have been better, but they will work fine.

I'm with Brett.....

A 48mm valve is only used on my engines for offroad use. This is because offroad engines need grunt and alot of flow at very low lifts to attain this.

That huge intake creates a hellacious charge that HAS TO GO SOMEWHERE and the cripped exhaust port of the Type IV head (especially a 1.7 head) make that a real challenge, even for a smaller valve.

These size valves are the most common mistake we see. That huge 48mm intake valve also creates huge concerns in piston/valve interferance as it protrudes down so far, and getting closer to the valve all the time.

what I"m saying has been provem on the flowbench, as well as on my dyno. The fact is that many of my 200+ HP engines feature a small 42 or 44mm intake valve and a 38mm exhaust, or 36mm. At the present we are working with a port shape for a 34mm valve to couple with a 40mm intake for high rev applications and the theory behind this is that the valve gets in the way of flow!

The huge 48mm intake valve is super heavy and hard to control. The gain he might have made in HP due to the valve (even if the ratios were perfect) would be soaked up by having to run 400 pounds of spring tension with duals just to control it! An uncontrolled valve is disaster waiting to happen!

The other area of concern that I have is the shrouding of that intake valve. That small 1.7 chamber isn't even unshrouded at all! Look how the cutter cut right into the beef around the chamber but no hand work was done to unshroud this. Basically that entire side of the valve will be useless at filling that chamber! (that might be a good thing in this particular situation)

Rimco does very good seat work, and general valve work. They don't take the time to unshroud, port and polish or to research to find the best combinations of valve sizes to attain particular ratios valuable to proper engine configuration. They are a production shop, not a custom engine or cylinder head shop.

The engine may run and operate well, but it won't be comparable to what it could be if it were effectively set up with the proper valves. He will notice a big boost in down low power and of course the engine will be stronger. Pay very careful attention to camshaft selection, as a split duration cam will be NECESSARY to get these heads to do anything! Also watch ignition timing and advance curves because that big charge likes to detonate at low revs.

Its all in the combo! Don't expect to get anything more than marginal power gains without perfecting that COMBINATION!

Yes the heads could have been made better-
-Correct valve/port sizing
-Correct I/E ratio
-Step cutting procedures to enhance cylinder sealing wile keeping proper quench
- Unshrouding and balancing chamber volumes


Get mad or pissed at me if you want- I'm giving you part of the theory behind the reasons our 2270 makes more power, runs cooler and lasts longer than a huge 2600 without the right combo! Its all dyno and track proven and the customers can't believe the results! The smallest of changes make drastic changes to the engine!

Maybe I should start back on my book sometime soon......... But the performance engine video will come next!

BTW, ensure he ccs those chambers, the heads must have had one hell of a flycut to need the top fin decked that much!

i have seen the flow numbers and they're not pretty ...

Andy

Probably well over 200 CFM on the intake and 125-130 on the exhaust if that...

How close am I??

worse ...

2.0L stock exhaust valve (36 mm)

lift - flow
==========

100 - 40 cfm
200 - 55 cfm
300 - 65 cfm
400 - 67 cfm


2.0L stock intake valve (42 mm)

lift - flow
==========

100 - 65 cfm
200 - 130 cfm
300 - 145 cfm
400 - 165 cfm
500 - 180 cfm


and this is *without* any headers/muffler which will restrict flow even more!

Andy

Andy,
An intake and exhaust pipe on the head during testing will actually help it..

Were these the heads that he is using or just data you had lying around??

The stock data we have from a 2.0 head that Len tested on his bench seen here http://www.aircooledtechnology.com/service...bench-flow.html

was much better than that...

my quote was actually data from *you* that you gave to brad quite a while ago ...

Andy

Could he help compensate for the big intake with a low lift? Or is that just silly? Semms like low lift might help keep velocity up.

If you are going to intentionally limit lift why bother with a valve this size. The problem, and I have seen this with the SBC, is the big valve shrouds the port too much. The smaller valve has a smaller area this not appearing to the air flow as being as big as it is. IN most cases the bigger valve is not fitted to the proper seat ID thus over hanging the seat and creating a smaller window. I will be taking several sets of heads over to Len's shop in a couple of weeks and will try and share some of the results. Most of these will be based on the Production rules using a modified 2.0 head though.

this matter was discussed at length around the table at dave's last night. that set of heads you were selling a while back was quite the deal jake.

kevin

well fuck....got the whole engine for 400 bucks....complete minus carbs...I will live...darn ....if it doesnt blow up, well....then I will have a smile on my face and my middle finger extended out the window... :finger2:

good attitude to have. dude. AX and D and G this weekend. hurry up.

Always gotta keep a good attitude with this crowd.

Put the motor in and go AX. You'll be able to walk the walk if not talk the talk.

yeah jay, you gotta try and beat me at the ax man. my skills and car vs youre pimped ride man!
i wanna help you dammit!!!!! college blows

exactly why i won't leave!

its pretty boring. damn commuter school, how much fun can a bunch of engineers have? lol. dorm life is fun, im uup 50 bucks in poker.
oh...time to study

Hey!! Listen up dickhead. I've struggled my whole life with a High School education. Be happy you have a chance to go to college. College blows but life without it blows even harder. Finish school or I will personally hunt you down and kick your young ass!!
Cheers, Elliot

damn, i did sound like a prick in that post. . i did work hard in high school etc, im saying that college is work without fun. it will pay off i know, but thats 5 years from now.

thanks elliot.
( i wouldnt mind flying planes. that would be fun)

join the army rofl....

good plan

QUOTE (DrifterJay @ Oct 18 2004, 12:05 AM)
join the army biggrin.gif rofl....

Hey Jared,

You can probably learn more in the Army than most do in College. The most important thing people learn in College is how to listen and learn and to finish things you start. Two lessons that alot of people just don't ever get.

Two lessons that are into you in the Miliitary!!