 DrifterJay's heads back from Rimco |
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| skline |
 Oct 15 2004, 10:48 PM
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#1
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Born to Drive  Group: Members Posts: 7,910 Joined: 26-December 02 From: Costa Mesa, CA Member No.: 17 Region Association: Southern California  |
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.
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Replies(1 - 19)
| Brett W |
Oct 15 2004, 11:06 PM
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#2
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Advanced Member Group: Members Posts: 2,856 Joined: 17-September 03 From: huntsville, al Member No.: 1,169 Region Association: None 
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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. |
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| Aaron Cox |
Oct 15 2004, 11:13 PM
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#3
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
QUOTE(Brett W @ Oct 15 2004, 10:06 PM) 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! |
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| skline |
Oct 15 2004, 11:48 PM
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#4
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Born to Drive Group: Members Posts: 7,910 Joined: 26-December 02 From: Costa Mesa, CA Member No.: 17 Region Association: Southern California |
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.
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| SirAndy |
Oct 15 2004, 11:52 PM
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#5
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Resident German Group: Admin Posts: 41,640 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Brett W @ Oct 15 2004, 10:06 PM) Bigger is not always better. i have to agree on that part, he should have opted for bigger exhaust valves instead, to help the engine breath ... (IMG:style_emoticons/default/cool.gif) Andy |
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| skline |
Oct 16 2004, 12:06 AM
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#6
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Born to Drive Group: Members Posts: 7,910 Joined: 26-December 02 From: Costa Mesa, CA Member No.: 17 Region Association: Southern California |
The dimensions are 48X38, what are the factory sizes?
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| maf914 |
Oct 16 2004, 06:32 AM
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#7
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Not a Guru! Group: Members Posts: 3,049 Joined: 30-April 03 From: Central Florida Member No.: 632 Region Association: None
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QUOTE(skline @ Oct 15 2004, 10:06 PM) The dimensions are 48X38, what are the factory sizes? Stock 2.0 liter is 42 x 36. (IMG:style_emoticons/default/idea.gif) |
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| machina |
Oct 16 2004, 06:44 AM
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#8
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Advanced Member Group: Benefactors Posts: 2,030 Joined: 21-June 03 From: Miami Beach, FL Member No.: 848  |
Don't listen to these guys, the heads are going to be just fine, plus they are nice and shiny. (IMG:style_emoticons/default/smile.gif)
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| SLITS |
Oct 16 2004, 10:05 AM
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#9
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
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............................ |
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| McMark |
Oct 16 2004, 02:07 PM
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#10
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
QUOTE(synthesisdv @ Oct 16 2004, 04:44 AM) Don't listen to these guys, the heads are going to be just fine, plus they are nice and shiny. (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/agree.gif) They will be fine. Could have been better, but they will work fine. |
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| Jake Raby |
Oct 16 2004, 02:55 PM
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#11
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
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- (IMG:style_emoticons/default/pissoff.gif) 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! |
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| SirAndy |
Oct 16 2004, 03:01 PM
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#12
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Resident German Group: Admin Posts: 41,640 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Jake Raby @ Oct 16 2004, 01:55 PM) what I"m saying has been provem on the flowbench, as well as on my dyno. (IMG:style_emoticons/default/agree.gif) i have seen the flow numbers and they're not pretty ... (IMG:style_emoticons/default/icon8.gif) Andy |
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| Jake Raby |
Oct 16 2004, 03:06 PM
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#13
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Probably well over 200 CFM on the intake and 125-130 on the exhaust if that...
How close am I?? |
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| SirAndy |
Oct 16 2004, 03:55 PM
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#14
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Resident German Group: Admin Posts: 41,640 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Jake Raby @ Oct 16 2004, 02:06 PM) Probably well over 200 CFM on the intake and 125-130 on the exhaust if that... 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! (IMG:style_emoticons/default/icon8.gif) Andy |
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| Jake Raby |
Oct 16 2004, 08:25 PM
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#15
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
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... |
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| SirAndy |
Oct 16 2004, 08:49 PM
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#16
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Resident German Group: Admin Posts: 41,640 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Jake Raby @ Oct 16 2004, 07:25 PM) The stock data we have from a 2.0 head that Len tested on his bench seen here [...] was much better than that... my quote was actually data from *you* that you gave to brad quite a while ago ... (IMG:style_emoticons/default/biggrin.gif) Andy |
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| McMark |
Oct 16 2004, 09:02 PM
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#17
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
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.
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| Brett W |
Oct 16 2004, 11:03 PM
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#18
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Advanced Member Group: Members Posts: 2,856 Joined: 17-September 03 From: huntsville, al Member No.: 1,169 Region Association: None
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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.
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| rhodyguy |
Oct 17 2004, 09:13 AM
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#19
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,080 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
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 |
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| DrifterJay |
Oct 17 2004, 10:11 PM
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#20
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I break stuff... Group: Members Posts: 1,034 Joined: 25-May 03 From: Oceanside, California Member No.: 737 Region Association: None |
well fuck....got the whole engine for 400 bucks....complete minus carbs...I will live...darn (IMG:style_emoticons/default/smile.gif) ....if it doesnt blow up, well....then I will have a smile on my face and my middle finger extended out the window... :finger2:
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