View Full Version : Rabbit 1.7 L Engine
ITCEd
11-20-2005, 08:25 PM
I am looking for advice on how to improve the performance of a 1.7L engine for ITC racing. I am new to this forum and would appreciate any help.
Ryan Williams
11-20-2005, 10:24 PM
If I remember right, you can raise the compression by 0.5 point, fully balance all internals, and port match for one inch the intake and exhaust. Beyond that, you are getting into illegal territory. A good race header is allowed.
Cheers, Ryan.
racer_tim
11-21-2005, 01:58 AM
I've got a fresh 1.7 short block sitting on my engine stand.
Crank bearings have been milled 100th and the rods have been milled 200th.
I learned to run a baffled oil pan.
Knestis
11-21-2005, 10:45 AM
You'd be well advised to not to ANYTHING until you carefully read the rulebook. Thankfully, it's available online now at the SCCA site.
Originally posted by racer_tim@Nov 21 2005, 05:58 AM
... Crank bearings have been milled 100th and the rods have been milled 200th.
I'm not following this - sorry.
Kirk (who's building an engine, too and keeps looking back at the book so he isn't trusting his failing memory)
racer14itc
11-21-2005, 11:23 AM
Originally posted by Knestis@Nov 21 2005, 02:45 PM
You'd be well advised to not to ANYTHING until you carefully read the rulebook. Thankfully, it's available online now at the SCCA site.
I'm not following this - sorry.
Kirk (who's building an engine, too and keeps looking back at the book so he isn't trusting his failing memory)
66123
Kirk, I think Tim means the crank has been ground .010" and .020" inch, respectively ("one hundredth and two hundredths").
To answer the original poster, there are several things that I'm curious about:
1. Can a "G" grind cam be used with the 1.7 engine? What cam with the 1.7? And can you even get a new part identical to it?
2. Does the 1.7 Rabbit in ITC have to use the 60mm airflow meter? I believe all the Westmoreland 1.7 Rabbits had the 60mm airflow meter, while the German built 1.7 Sciroccos used the 80mm airflow meter. However, make sure the P/N on the airflow meter matches your cars make/model/year. That's what got Derek at the SIC, BTW. Even though the airflow meter on his car was functionally, dimensionally, and in all respects the correct airflow meter, the P/N on it did not match up to the shop manual. VW tagged different airflow meters differently depending on whether they were going into a Jetta, Rabbit, Scirocco, etc. Very, very PICKY if you ask me. :bash_1_:
3. Does the block number have to match up to the 1.7? Good luck finding a good one. In Prod, we can use dimensionally identical blocks but I'm not sure if IT that is allowed.
4. Are there different throttle bodies for the 1.7 vs. the 1.6? I used to have a box full of those things before I switched to Weber carbs, and each one seemed to have a different combination of vacuum line ports. Do you have to use only the ones that came on a 1.7?
The irony here (and I'm hijacking the thread here a bit) is that Derek got bounced for a NON-issue at the SIC (identical part except for the model P/N), but a couple of years ago a guy won the SIC ITC race with a 2nd Gen Honda with a 5 spd, lightened flywheel, questionable camshaft, and a VIN that didn't match up to the model...and he went through unscathed. :angry:
MC
Bill Miller
11-21-2005, 01:36 PM
Mark,
Not to continue the hijack of this thread, but if that Honda had all those known issues, why wasn't it protested by other drivers? The VIN# one would seem to be a slam dunk, and pretty easy to verify. As far as Derek's issue, did anyone check the VW parts database to see what that p/n crossed to?
racer14itc
11-21-2005, 01:48 PM
Originally posted by Bill Miller@Nov 21 2005, 05:36 PM
Mark,
Not to continue the hijack of this thread, but if that Honda had all those known issues, why wasn't it protested by other drivers? The VIN# one would seem to be a slam dunk, and pretty easy to verify. As far as Derek's issue, did anyone check the VW parts database to see what that p/n crossed to?
66151
Bill,
I don't know. I wasn't racing in that class anymore by then, but I did watch the "race" from the sidelines. It was funny watching an ITC Honda draft with Sam Moore's Volvo and pass SM's down the straight at Roebling. <_< Nobody in the class seemed to be too concerned about it at the time, which I thought was odd. And boy was Scott sure unhappy about what he found after he bought the "SIC Winning ITC Civic". :014:
But it sure seems like Derek's had a big ol' bullseye on his butt this year, because people have been after him from the get-go.
You'll have to ask Derek for the specifics on the part number. All I know is that his didn't match the manual and he couldn't prove the number that was on the one he had came on a 1.7 Scirocco.
Back on topic:
ITCed: once you determine the proper camshaft and airflow meter for the 1.7 Rabbit, I'd suggest the usual IT engine prep procedures to find horsepower. Balance, match port, get a good exhaust header, put a crank-scraper in the pan, etc. Clearances on the mains and rod bearings can be opened up a bit to release some hp, the VW's are good about having enough oil pressure.
Good luck!
MC
Bill Miller
11-21-2005, 03:49 PM
Mark,
Sorry to hear that people have been gunning for Derek. I'm guessing that someone knew what they were looking for when he was protested. I can't see that being something a tech guy is going to look for, out of the blue. As far as that Honda goes, that's a prime example of what happens when nobody does anything. I remember someone telling me that they went to look at an ITB Rabbit GTI. He looked at the cam through the oil filler. Didn't look quite right. Pulled the valve cover off, and low and behold, it was a hydraulic lifter head!! :o :119:
Back on topic. As Kirk said, read the rules first. Make sure the car is an '81-'84 car, and can legally run a 1.7.
Campbell
11-21-2005, 05:12 PM
ITC Ed,
I think Mark's suggestion to look into the big bore airflow is a good suggestion, as well as the cam. You can also go .040 over on the bore as well.
Good luck
racer14itc
11-21-2005, 05:25 PM
Originally posted by Campbell@Nov 21 2005, 09:12 PM
ITC Ed,
I think Mark's suggestion to look into the big bore airflow is a good suggestion, as well as the cam. You can also go .040 over on the bore as well.
Good luck
66198
Actually Campbell, I was kinda going the other way. IIRC, the 1.7 Rabbits all had the 60mm airflow meter and would have to use it w/ a 1.7 engine in ITC. Unless of course you can document that a 1.7 came with a 80mm airflow meter.
I'm pretty sure the 1.6's all came with 80mm airflow meters. If someone is looking to upgrade to a 1.7 in their ITC Rabbit, this might be something to ponder (you'd have to run the smaller airflow meter w/ the 1.7 engine). Also, I don't think that you could get the g-cam allowance for the 1.7 engine. All the "documentation" was done for the 1.6 engine, from what I can remember.
Also, the 1.7 Rabbit only gets the WIDE ratio 5 spd, not even as good as the gearbox allowed in the 1.6 Rabbit in ITC.
All in all, I don't think the 1.7 Rabbit is a good package for ITC. IMHO.
MC
Bill Miller
11-21-2005, 05:41 PM
Originally posted by racer14itc@Nov 21 2005, 05:25 PM
Actually Campbell, I was kinda going the other way. IIRC, the 1.7 Rabbits all had the 60mm airflow meter and would have to use it w/ a 1.7 engine in ITC. Unless of course you can document that a 1.7 came with a 80mm airflow meter.
I'm pretty sure the 1.6's all came with 80mm airflow meters. If someone is looking to upgrade to a 1.7 in their ITC Rabbit, this might be something to ponder (you'd have to run the smaller airflow meter w/ the 1.7 engine). Also, I don't think that you could get the g-cam allowance for the 1.7 engine. All the "documentation" was done for the 1.6 engine, from what I can remember.
Also, the 1.7 Rabbit only gets the WIDE ratio 5 spd, not even as good as the gearbox allowed in the 1.6 Rabbit in ITC.
All in all, I don't think the 1.7 Rabbit is a good package for ITC. IMHO.
MC
66202
Mark,
You can't legally 'upgrade' to a 1.7 in an ITC Rabbit. You can run a '75 - '80 w/ either of the 1.5s or a 1.6, or you can run an '81 - '84 w/ a 1.7. That's why I made my earlier comment about checking to make sure it was a car that came w/ a 1.7. Now, if we get them to combine all the ITC Rabbits on the same spec line, w/ different motors @ different weights, this would be a moot point. They've already got the 1.5s and the 1.6 on the same spec line, why not just add the 1.7s and list another trans configuration and weight?
Side note (yet another one) why is the 1.7 a 70# penalty for the Scirocco Is, but only a 50# penalty for the Rabbits?
ITCEd
11-22-2005, 11:08 PM
Thanks for the comments. I get the feeling that a 1.7 would not be everyone's choice for an ITC Rabbit ???
I realize that I need to watch the rules. I am as concerned about being legal as everyone else is.
ITCEd
[quote]
Mark,
Not to continue the hijack of this thread, but if that Honda had all those known issues, why wasn't it protested by other drivers? The VIN# one would seem to be a slam dunk, and pretty easy to verify. As far as Derek's issue, did anyone check the VW parts database to see what that p/n crossed to?
66151
SEE JAN FAST TRACK' THE PART IN QUESTION WAS NOT AN OE VW PART BUT A AFTERMARKET BOSCH HP AIRFLOW METER. SEE BILDON ONLINE CATALOG, A 8%HORSEPOWER GAIN IS CLAIMED FOR THIS VW MOTORSPORT UNIT......AL HARRIMAN
racer_tim
11-23-2005, 01:48 AM
Thanks for the correction's Mark.
BTW, the 1.6 is a much better crank / rod setup than the 1.7
racer14itc
11-23-2005, 09:40 AM
Originally posted by al h@Nov 23 2005, 04:43 AM
SEE JAN FAST TRACK' THE PART IN QUESTION WAS NOT AN OE VW PART BUT A AFTERMARKET BOSCH HP AIRFLOW METER. SEE BILDON ONLINE CATALOG, A 8%HORSEPOWER GAIN IS CLAIMED FOR THIS VW MOTORSPORT UNIT......AL HARRIMAN
66425
Al, you are exactly right. I am disappointed because Derek failed to mention that little tidbit during our conversations. I was under the impression that it was simply an OE unit from another car.
The DQ and suspension are justified in this case. :018:
MC
Bill Miller
11-23-2005, 11:15 AM
Originally posted by racer14itc@Nov 23 2005, 09:40 AM
Al, you are exactly right. I am disappointed because Derek failed to mention that little tidbit during our conversations. I was under the impression that it was simply an OE unit from another car.
The DQ and suspension are justified in this case. :018:
MC
66442
Yep, that's a shame. Certainly explains why the car seemed so honkin fast.
Not to hijack this thread even more, but IIRC, Derek's penalty was significantly more severe than the one for the driver involved in Jake et al's protest from last year.
In Derek's case, I saw that the gear ratios were also in question. Did they tear his tranny down? If so, did he get the bond for that, even though there was another, unrelated non-compliant part found?
racer_tim
11-23-2005, 03:07 PM
All the COA says is that " the gear ratios were found to be stock and compliant".
[quote]
All the COA says is that " the gear ratios were found to be stock and compliant".
66486
THE RATIOS WERE CHECKED BY TURNING WHEELS. NO TEAR DOWN. THE CAR HAD A 1.13 4TH, ACLOSE RATIO TRANS. THIS TRANS WILL BE PROVEN TO WRONG EVENTUALLY IT GOT ON THE SPEC LINE FOR THIS CAR ON SOME VERY THIN GROUNDS, CHECK ANY PRIOR GCR. ALSOTHE CAR HAD NO VIN PLATE.
golfracer
11-23-2005, 08:29 PM
Originally posted by al h@Nov 23 2005, 11:53 PM
THE RATIOS WERE CHECKED BY TURNING WHEELS. NO TEAR DOWN. THE CAR HAD A 1.13 4TH, ACLOSE RATIO TRANS. THIS TRANS WILL BE PROVEN TO WRONG EVENTUALLY IT GOT ON THE SPEC LINE FOR THIS CAR ON SOME VERY THIN GROUNDS, CHECK ANY PRIOR GCR. ALSOTHE CAR HAD NO VIN PLATE.
66517
Al,
you seem to know a lot about this. Can you tell us how the car received a log book with out a vin? Are you sure it just wasnt because the car didnt have 2 vin locations?
George Stein
Bill Miller
11-23-2005, 09:42 PM
Originally posted by al h@Nov 23 2005, 07:53 PM
THE RATIOS WERE CHECKED BY TURNING WHEELS. NO TEAR DOWN. THE CAR HAD A 1.13 4TH, ACLOSE RATIO TRANS. THIS TRANS WILL BE PROVEN TO WRONG EVENTUALLY IT GOT ON THE SPEC LINE FOR THIS CAR ON SOME VERY THIN GROUNDS, CHECK ANY PRIOR GCR. ALSOTHE CAR HAD NO VIN PLATE.
66517
Al, regardless of the information you have on this car, it's considered bad form to 'yell' (all caps). As someone else pointed out, you seem to have a lot of info on this car. I noticed that you were not the driver that protested it. If you have so much info on this car, and feel that it is/was illegal, why didn't you protest it?
Happy Thanksgiving, one and all! :023:
Originally posted by Bill Miller@Nov 23 2005, 08:42 PM
Al, regardless of the information you have on this car, it's considered bad form to 'yell' (all caps). As someone else pointed out, you seem to have a lot of info on this car. I noticed that you were not the driver that protested it. If you have so much info on this car, and feel that it is/was illegal, why didn't you protest it?
Happy Thanksgiving, one and all! :023:
66532
Sorry about caps, new to chat. Just giving account of what i observed.
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