Hi, im building a 1300 motor and i want to make it a little hottie, itll suit my car, but i wana leave it as a 1300 for a bit of a challenge
i will have dual carbs (Solex) with a fram filter, what else can i do
ive heard
1600 rockers, larger valves, head porting
what do u think that would make this a wild little 1300 daily driver?
1300 hottie
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RoWaMe
- Posts: 1698
- Joined: Fri May 24, 2002 12:01 am
In the USA, the 1300 engine was only offered in 1966 and had single-port heads. Is that what you have, or are you in Europe where the 1300 was also a dual-port in the '70's?
Do you want to open the engine case up to install a mild cam (no more than an Engle 100 or Scat C-25, or similar), or even install a stroker crankshaft? If you go for any cam other than the stock one, you should install single heavy-duty springs in the heads. Steel pushrods (like the ones Gene Berg sells) are a good idea too, whereby some companies sell good HD aluminum pushrods (www.aircooled.net).
Are the "dual Solexes" you mention the 34mm that CBPerformance now offers, or used ones from a Type 3 (32 PDSIT), or the 40mm Solex-Kadrons?
The 1300 single-port head had small valves compared to the 1500 SP head and the 1600 dual-port;s all those had 35x32 valve sizes; the 1300 was 32x30, I think. The 1300 single-port head's intake runner is also slightly smaller inner diameter than on the 1500 single port's head, but you can do some porting in there to open it up a bit.
1300 rockers and 1600 rockers are the same at 1.1:1. So no advantages there. You can buy 1.25:1 rockers that look like a VW casting from various sources (around $100) that slip onto your stock rocker shafts (or buy HD shafts for about $40) which should give you a slight power increase. But the biggest increase will be with the dual carbs, matched to a 1 3/8" header. It's quite an expense to have your 1300 valves replaced with the 1500/1600 valves, since the valve seats must be removed, the head machined for the larger size seats and the new ones set in. If you do decide to do that, have the shop also perform a good 3-angle valve job. See Rimco's website for prices which are representative (www.rimcovw.com) to see if that work and $$ is worth it to you.
A year ago I also had a US-spec 1300 to play with. I installed the 83mm P&C from a 1500 engine, which required having the heads bored open but not the case. Kept the small 1300 original valves but did port the heads a bit in the intake runners. Installed an Engle 100 cam, set the CR to about 7.8 and have Kadrons (40mm single-throat Solexes). Runs well; will keep my '64 Ghia coupe easily at 80mph (but the engine is buzzing on the highway at about 4500 rpms with its stock 4.38 tranny).
Do you want to open the engine case up to install a mild cam (no more than an Engle 100 or Scat C-25, or similar), or even install a stroker crankshaft? If you go for any cam other than the stock one, you should install single heavy-duty springs in the heads. Steel pushrods (like the ones Gene Berg sells) are a good idea too, whereby some companies sell good HD aluminum pushrods (www.aircooled.net).
Are the "dual Solexes" you mention the 34mm that CBPerformance now offers, or used ones from a Type 3 (32 PDSIT), or the 40mm Solex-Kadrons?
The 1300 single-port head had small valves compared to the 1500 SP head and the 1600 dual-port;s all those had 35x32 valve sizes; the 1300 was 32x30, I think. The 1300 single-port head's intake runner is also slightly smaller inner diameter than on the 1500 single port's head, but you can do some porting in there to open it up a bit.
1300 rockers and 1600 rockers are the same at 1.1:1. So no advantages there. You can buy 1.25:1 rockers that look like a VW casting from various sources (around $100) that slip onto your stock rocker shafts (or buy HD shafts for about $40) which should give you a slight power increase. But the biggest increase will be with the dual carbs, matched to a 1 3/8" header. It's quite an expense to have your 1300 valves replaced with the 1500/1600 valves, since the valve seats must be removed, the head machined for the larger size seats and the new ones set in. If you do decide to do that, have the shop also perform a good 3-angle valve job. See Rimco's website for prices which are representative (www.rimcovw.com) to see if that work and $$ is worth it to you.
A year ago I also had a US-spec 1300 to play with. I installed the 83mm P&C from a 1500 engine, which required having the heads bored open but not the case. Kept the small 1300 original valves but did port the heads a bit in the intake runners. Installed an Engle 100 cam, set the CR to about 7.8 and have Kadrons (40mm single-throat Solexes). Runs well; will keep my '64 Ghia coupe easily at 80mph (but the engine is buzzing on the highway at about 4500 rpms with its stock 4.38 tranny).
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Marc
- Moderator
- Posts: 23741
- Joined: Thu May 23, 2002 12:01 am
Like RoWaMe, I'd like to know what flavor of 1300 you have.
To make any serious power out of a 1300 you'll need to buzz it pretty hard.
Obviously you don't care about keeping the appearance stock with dual carbs, so dualport heads are in order. The Euro-spec 1300DP heads already have 35.5x32 valves (they're basically the same head as a 1600DP, just not bored out as big and with a smaller chamber) - 35.5s will actually hit the cylinders with a 77 bore if you have a lot of lift and/or flycut for a lot of compression - you might need to clearance the cylinders slightly - obviously the cylinders are shrouding the intake valves pretty badly already so going larger probably isn't worth the effort...but some porting would be. If you don't have 1300DP heads, 1600DPs will work - the wide seating surface of the 77mm cylinders makes it relatively easy to get them to sit down squarely even without spacer rings, or you can have them step-cut for the smaller jugs. Even if you want to stay with SP heads, using 15/1600 parts would be the way to go rather than putting larger valve seats into 1300 (33x30) heads.
The lighter pistons will let you rev to 5500 or so before the crank-flex gets bad enough to pound the case badly, but a counterweighted crank would still be wise, at least if you go DP. Short gearing (or at least small tires) will probably be needed
To make any serious power out of a 1300 you'll need to buzz it pretty hard.
Obviously you don't care about keeping the appearance stock with dual carbs, so dualport heads are in order. The Euro-spec 1300DP heads already have 35.5x32 valves (they're basically the same head as a 1600DP, just not bored out as big and with a smaller chamber) - 35.5s will actually hit the cylinders with a 77 bore if you have a lot of lift and/or flycut for a lot of compression - you might need to clearance the cylinders slightly - obviously the cylinders are shrouding the intake valves pretty badly already so going larger probably isn't worth the effort...but some porting would be. If you don't have 1300DP heads, 1600DPs will work - the wide seating surface of the 77mm cylinders makes it relatively easy to get them to sit down squarely even without spacer rings, or you can have them step-cut for the smaller jugs. Even if you want to stay with SP heads, using 15/1600 parts would be the way to go rather than putting larger valve seats into 1300 (33x30) heads.
The lighter pistons will let you rev to 5500 or so before the crank-flex gets bad enough to pound the case badly, but a counterweighted crank would still be wise, at least if you go DP. Short gearing (or at least small tires) will probably be needed
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Guest
Hey thanks guys for the info,
its a single port engine from an austalian model beetle,like the US spec 1966 one) the dual carbs will be those that were originally put on the motor as a single carb rejetted just 2 of them, im putting a Fram filter on and plumbing that in and going for a kind of okrasa look, i wouldnt like to open the case but i may do that, but prefer just little things that i can do that will maximise my opwer, just something for fun
its a single port engine from an austalian model beetle,like the US spec 1966 one) the dual carbs will be those that were originally put on the motor as a single carb rejetted just 2 of them, im putting a Fram filter on and plumbing that in and going for a kind of okrasa look, i wouldnt like to open the case but i may do that, but prefer just little things that i can do that will maximise my opwer, just something for fun