| Author |
Message |
oldschool5er
Samba Member
Joined: May 28, 2007
Posts: 804
Location: Ohio
|
 Posted: Tue Mar 21, 2017 8:43 am Post subject: Re: rally motor build suggestions |
 |
|
| boroko wrote: |
Lucky for me the engine rules are pretty open. Just size vs. weight.
I subscribe to the philosophy of Smokey Yunick who was well known for finding weaknesses in the rules. This isn't racing for money, its more for the personal challenge, so no need for me to stretch too far. And I have the personal pleasure of doing it right.
From what I'm learning, it looks like small stroke, big bore is a better way to go for a number of reasons. That means you need lighter parts to make it last. Oh well, its only money, right? |
But for the sake of discussion can you formalize your original statements of a 3k to 5500 torgue and power band and if still in the lower weight class? If you are going to use any head, any crank, any piston, any NA induction then it is wide open on engine design based on weight class. I am still curious as to what you are going for and expected weight range versus engine design. I have not even heard about transmission gearing needed or the speeds they achieve in the Rallys up there, is this a Rally with long straights and broad curves, hilly, or even short straights and tight turns or all of it? I am only asking because I am interested in this type of racing up there and seems a real potential for dirt track type racing which I am interested in also. No place out here to run my cars except MI seems like.
_________________
HRE in Westerville,Ohio
Full machine shop with all types of CNC. Rapid prototyping available, CNC Plasma cutting, 3D printing and Laser engraving. |
|
| Back to top |
|
 |
slalombuggy
Samba Member
Joined: July 17, 2010
Posts: 9147
Location: Canada
|
| Posted: Tue Mar 21, 2017 9:33 am Post subject: Re: rally motor build suggestions |
|
|
What about going to a short stroke 64mm x 90.5 engine to give the valves some room to breath? .04 deck,26cc chambers = 13:1 on E85 
brad |
|
| Back to top |
|
|
Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7219
Location: Videbaek Denmark
|
| Posted: Tue Mar 21, 2017 10:46 am Post subject: Re: rally motor build suggestions |
|
|
| slalombuggy wrote: |
What about going to a short stroke 64mm x 90.5 engine to give the valves some room to breath? .04 deck,26cc chambers = 13:1 on E85
brad |
IMHO destrokers are not the best solution to this kind of racing. asphalt track racing, fine.
Don´t know if turbo engines are allowed in that class, could be neat though.
I let the analyzer paly with a couple ofcombo´s using the 2070 cc displacement 74 x 94 mm. and one with a split dur cam, Ti valves and Oteva springs, modified IDA´s and a Wasp header from JP Motorsport and set them up for E85. That one pulled 217 hp @ 7250 with peak torque at 177 lbs @ 5700 and a usable power band from about 4500 to 7500 rpm.
A more "conservative" set up with a cheaper straight header and a US camshaft gave me 195 hp@ 6800 with peak torque at 170 lbs @ 5400 with a usable powerband between approx 4000 and 7250 rpm.
I don´t like 42 x 37,5 valved heads on such engines unless a split duration cam is used. The reason is that you have a too efficient exhaust side, which result in loss of torque in the lower to mid rpms. One the stove is hot they´ll perform well. with a split cam you can adjust the I/E ratio to what you want and restore the torque band (or move it around, which ever you want.)
So it is definitely possible to make a good set up that can kick some butt if you have the cahoneys to exploit it  
T
PS. This vid is from the Finnish classic winter rally. They run in the 1600 class, with engine power in the 145 -160+ hp. https://www.youtube.com/watch?v=_N9f1XZXg-w |
|
| Back to top |
|
|
Vagtastic Van
Samba Member
Joined: September 04, 2014
Posts: 17
Location: UK
|
| Posted: Wed Mar 22, 2017 6:14 am Post subject: Re: rally motor build suggestions |
|
|
So Alstrup, you are telling me those are all N/A 1600cc motors?!
I am going to spend some time watching Finnish rallying now |
|
| Back to top |
|
|
boroko
Samba Member
Joined: September 11, 2012
Posts: 326
Location: S.W. Michigan
|
| Posted: Wed Mar 22, 2017 9:23 am Post subject: Re: rally motor build suggestions |
|
|
| Quote: |
| But for the sake of discussion can you formalize your original statements of a 3k to 5500 torgue and power band and if still in the lower weight class? If you are going to use any head, any crank, any piston, any NA induction then it is wide open on engine design based on weight class. I am still curious as to what you are going for and expected weight range versus engine design. I have not even heard about transmission gearing needed or the speeds they achieve in the Rallys up there, is this a Rally with long straights and broad curves, hilly, or even short straights and tight turns or all of it? I am only asking because I am interested in this type of racing up there and seems a real potential for dirt track type racing which I am interested in also. No place out here to run my cars except MI seems like. |
The statement about torque was just throwing something out there. Emphasis on wide torque, and not on a 500rpm power band. In the couple of days that I have been reading, I'm beginning to realize that I can probably go higher. Obviously I can if I want to spend 10k on the motor, but that's not the goal. Seat time is the first goal. As I get that I'll have a much more intelligent view of what I really need.
A turbo is the obvious way to gain power, but that puts me in a class that is much more competitive. As a reference point, one of the cars that I crew on is a Subi BRZ with engine management coming in about 190-200hp. Way more than I expected to get from an A/C. I have been in contact with a few guys that have raced this type and I'm trying to learn what they felt they needed.
_________________
'87 SyncroWesty: Smokey the Turtle, '85 SubiWesty: Chappie, '84 GTI, '86 GTI in full Rally trim,
previous: 2 Syncro tin tops, 2 Vanagons, 3 busses, 3 Ghias, 2 Jettas, a 411, a gas and a diesel Bunny and about 25 Beetles, one that only drove left. |
|
| Back to top |
|
|
Pruneman99
Samba Member
Joined: February 22, 2012
Posts: 5013
Location: Oceanside
|
| Posted: Wed Mar 22, 2017 6:37 pm Post subject: Re: rally motor build suggestions |
|
|
| A destroked revver motor with a light valve train sure would sound cool. When you pass someone, they would think your car was powered by loud, angry bees. I have a buddy that builds motorcycles, and he is always trying get me a to build a destroked revver. Not sure if it would be optimal or not. Is there a lot of on throttle off throttle? I would think an engine like that would want to stay high up in the rpm band. This is all just a completely uneducated guess. I'm sure someone out there has gone short stroke, large bore that could give you real life experience. It sure would let the heads work though. |
|
| Back to top |
|
|
boroko
Samba Member
Joined: September 11, 2012
Posts: 326
Location: S.W. Michigan
|
| Posted: Wed Mar 22, 2017 6:49 pm Post subject: Re: rally motor build suggestions |
|
|
From almpst everything I'm seeing, the thing is really "build some heads and put a motor under it".
I really had no idea that the bottom end with some basic prep is able to handle pretty crazy revs. I guess I never had the occasion to see it done. Lighter pistons, counterweight, and a valve train is where all the effort is. Or at least, that's I'm hearing from a number of people.
Having been out of A/C'd for so long is kind of like having Alzheimer's, every thing is always new and exciting.
I'm becoming less nervous about a reving motor. Besides, it sure sounds nice!
bo
_________________
'87 SyncroWesty: Smokey the Turtle, '85 SubiWesty: Chappie, '84 GTI, '86 GTI in full Rally trim,
previous: 2 Syncro tin tops, 2 Vanagons, 3 busses, 3 Ghias, 2 Jettas, a 411, a gas and a diesel Bunny and about 25 Beetles, one that only drove left. |
|
| Back to top |
|
|
Pruneman99
Samba Member
Joined: February 22, 2012
Posts: 5013
Location: Oceanside
|
| Posted: Wed Mar 22, 2017 7:09 pm Post subject: Re: rally motor build suggestions |
|
|
I know there is a thread here somewhere where someone took a stock single port, turboed it a ran it like a rented mule for years before a failure. That was on non-counterrweighted crank. Not saying that's the normal, but the bottom ends can sure take some abuse.
Another guy I saw built a light valve train engine and was dynoing it at over 10k. The sound was teeth clenching.
It can be done with proper planning and a few greenbacks for sure.
I vote for the de-stroker because it's your money and I want to see it  |
|
| Back to top |
|
|
madmike
Samba Member
Joined: July 11, 2005
Posts: 5292
Location: Atlanta,Michigan
|
| Posted: Thu Mar 23, 2017 3:59 am Post subject: Re: rally motor build suggestions |
|
|
I'd build a 2276 with a close ratio trans 
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works" |
|
| Back to top |
|
|
owdlvr
Samba Member
Joined: June 23, 2008
Posts: 684
Location: Squampton BC
|
| Posted: Sat Mar 25, 2017 10:57 am Post subject: Re: rally motor build suggestions |
|
|
Just out of curiosity, have you looked into Mark and John Huebbe's build? They rallied their beetle in the RA series for many years/events.
-Dave
_________________
---
Instagram: @DaveHord
1971 1302s - Salzburg Tribute the #RallyBug
1958 Beetle
1975 Beetle
1973 Super Beetle
1993 C3500 with Cummins swap
1967 MGB
1963 MG Midget |
|
| Back to top |
|
|
boroko
Samba Member
Joined: September 11, 2012
Posts: 326
Location: S.W. Michigan
|
| Posted: Sat Mar 25, 2017 12:07 pm Post subject: Re: rally motor build suggestions |
|
|
I looked at all that i could find about them, but could never find a build log concerning their motor. I finally did find a way to contact Mark, and he was gracious enough to talk to me a few days ago. I was furiously scribbling notes and have to condense them now. I'm hoping to catch up with him at Southern Ohio Forests Rally.
_________________
'87 SyncroWesty: Smokey the Turtle, '85 SubiWesty: Chappie, '84 GTI, '86 GTI in full Rally trim,
previous: 2 Syncro tin tops, 2 Vanagons, 3 busses, 3 Ghias, 2 Jettas, a 411, a gas and a diesel Bunny and about 25 Beetles, one that only drove left. |
|
| Back to top |
|
|
tdrrally
Samba Member
Joined: January 05, 2011
Posts: 181
Location: charleston,wv.
|
| Posted: Mon Apr 10, 2017 4:10 pm Post subject: Re: rally motor build suggestions |
|
|
| boroko wrote: |
| I looked at all that i could find about them, but could never find a build log concerning their motor. I finally did find a way to contact Mark, and he was gracious enough to talk to me a few days ago. I was furiously scribbling notes and have to condense them now. I'm hoping to catch up with him at Southern Ohio Forests Rally. |
i'm working on a beetle too, i will be at SOFR as a volunteer, i'm planning to drive my beetle there
Last edited by tdrrally on Tue Apr 11, 2017 3:37 am; edited 1 time in total |
|
| Back to top |
|
|
madmike
Samba Member
Joined: July 11, 2005
Posts: 5292
Location: Atlanta,Michigan
|
| Posted: Tue Apr 11, 2017 2:59 am Post subject: Re: rally motor build suggestions |
|
|
Hey TDRRally, Do check out the 'Punisher' That's my Son Shawn, he really puts on a good show alway on the throttle or the brakes,
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works" |
|
| Back to top |
|
|
tdrrally
Samba Member
Joined: January 05, 2011
Posts: 181
Location: charleston,wv.
|
| Posted: Thu Apr 13, 2017 3:57 am Post subject: Re: rally motor build suggestions |
|
|
back to the question at hand
for my rally beetle i'm planning to build a stock crank 1835 with a single hpmx
do to a very limited budget.
if you have never rallied before stock with a strong stock to 1835 engine focus on the suspension chassis brakes and your self before worrying about big power
ideally you want a strong mid range with a linear power band like an electric motor drive ability to me is more important than power, its easier to go fast in a forgiving car than to fight the road and the car to go fast. |
|
| Back to top |
|
|
|
